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1
7
HAH
US Army Corps
of Engineers
NEW YORK DISTRICT
GENERAL DESIGN
MEMORANDUM
SHINNECOCK INLET PROJECT
Long Island, New York
SUPPLEMENTAL DOCUMENTATION
COST ESTIMATE
ENGINEERING AND PROJECT
DESIGN CONSIDERATION
STONE STRUCTURAL
REHABILITATION AND REPAIR
BENEFIT EVALUATION
FINAL REPORT
JUNE 1987
REVISED MARCH 1988
COST ESTIMATES AND APPORTIONMENT
APPENDIX B
APPENDIX 5
COST ESTIMATES AND APPORTIONMENT
TABLE OF CONTENTS
Paragraph
Subject
Page
I COST ESTIMATE
B1
Introduction
31
B2
Basis of Cost
B1
B6
Alternatives Considered
32
B10
Recommended Plan
B3
B12
Estimated First Cost
33
B13
Contingency, Engineering, Design,
34
Supervision and Admimistration
314
Construction and Funding Schedule
34
315
Real Estate
34
II COMPARISON OF COST ESTIMATES
B16
Comparison of GDM Estimate With
B4
Authorized Document and Latest P3-3
B17
Channels
B5
B18
Jetties
B5
B19
Permanent Operating Equipment
35
B20
Engineering and Design
B5
B21
Supervision and Administration
B5
III ANNUAL CHARGES
B22
General
B5
B23
Periodic Dredging of Deposition Basin
B5
""
TABLE OF CONTENTS
Paragraph
Subject
Page
III ANNUAL CHARGES (continued)
B25
Periodic Dredging of Fishing Facility
E5
Dock Area
B26
Stone Structure Maintenance
B6
B27
Annual Charges
B7
IV APPORTIONMENT OF COSTS BETWEEN INTERESTS
B28
General
B7
B29
Apportionment
B7
V DEVELOPMENT OF ALTERNATIVE CONSTRUCTION METHODS
330
General
37
331
Other Dredging Plants Considered
B7
LIST OF TABLES
Number
Description
Page
B1
Alternative Channel/Basin Sizes
39
Total Annual Costs
B2
Deposition Basin-Initial Construction
B10
Volumes and Maintenance Dredging
Requirements of Channel Alternatives
B2A
Total First Cost and Annual Cost for
B12
the Jetty Extension with Fixed Sand
Bypassing Plan Alternative
B2B
Detailed Estimate of Fixed Sand By-
B13
passing Plan
B2C
Detailed Estimated Stone Work for Jetty B15
Extension Plan
ii
LIST OF TABLES
Number
Description
Page
B3
Summary of Investment Costs -
Recommended Plan
B16
B4
Alternative Channel/Basin Sizes
B:8
Total First Costs (Excluding Non-
Federal Dredging)
B5
Alternative Channel/Basin Sizes
319
Annualized Dredging Maintenance Costs
(Excluding Non-Federal Dredging)
B6
Detailed Estimate- Initial Construction 320
of Recommended Plan For Dredging
B7
Total Annual Cost- Recommended Plan
B21
3a
Apportionment of Costs-Recommended
B22
Plan
B9
Uniform Feature Breakdown of Estimate
B23
of First Cost
B10
Construction and Expenditure Schedule
B24
iii
APPENDIX B - COST ESTIMATES
AND APPORTIONMENT
I - COST ESTIMATE
B1. INTRODUCTION: This Appendix presents cost estimates for
initial construction, annualized maintenance, cost
apportionment and total annual costs for a single purpose
navigation improvement which provides the following: (1) an
inner channel within Shinnecock Bay with a minimum width of
100 ft. at a depth of (-) 6 mlw, (2) an outer channel with
a width of 200 ft. at el (-) 10 mlw from its connection with
the inner channel at the Bay side of the Inlet, through the
Inlet and across a bar area to deeper water in the ocean; the
channel is to be enveloped by a deposition basin 2600 ft
long, 800 ft. wide to el. (-) 20 mlw oceanward of the jetties
for advanced maintenance, (3) rehabilitation of the existing
east and west jetties and (4) construction of a 1,000 ft.
long revetment facing the Bay, east of the Inlet, extending
from the Bay side of the jetty to provide beach erosion
control for the integrity of the east jetty. It is to be
noted that no construction is involved for provision of the
inner channel. Refer to Plate No. 4 for the plan layout.
B2. BASIS OF COSTS. Cost estimates presented herein are
based on October 1986 price levels. The quantities for
dredging and revetment construction are based on the detailed
plans as shown in the main body on Plate No. 4 and 5 which
were developed from June 1985 hydrographic and topographic
surveys. The quantities for jetty rehabilitation were based,
in part, on a jetty conditions survey in March 1986 and, in
part, from the June 1985 survey mentioned previously. The
unit prices were developed on the basis that the construction
procedures and schedule will be as outlined herein.
B3. Dredging cost estimates are based on the use of a 27"
hydraulic dredge. The cost estimates are based on pumping
dredged material equivalent to 61,000 c.y. annually for each
dredging operation on the beach front within 3,000 ft. west
of the Inlet, and pumping the remaining dredged material
offshore, approximately 5,000 ft. west of the Inlet.
Material is required on the beach within 3,000 ft. west of
the Inlet to stabilize this beach area which historically
has suffered significant erosion. Without stabilization,
it is anticipated, based on erosion rates discussed in
Appendix C, that a breach could occur as early as 10 years
(1996) which will cause serious problems to the stability of
the Inlet system. Dredged material placed offshore 5,000 ft
downdrift of the Inlet will provide necessary sand bypassing
to maintain the littoral flow of material westward across the
Inlet. A 5,000 ft. pumping distance is required to preclude
pumped material from flowing back towards the Inlet area due
B1
to the existence of a nodal point along the shoreline 5,000
ft. west of the Inlet.
34. The production rate unit cost for dredging utilized for
the (-) 20 mlw and (-) 22 mlw basin depth alternatives is
$6.50/c.y. For the (-) 18 mlw basin depth alternatives, a
unit production rate of $7.50/c.y. is utilized due to
additional non pay yardage required. A mobilization and
demobilization cost of $500,000 is utilized for all
alternatives.
35. The cost for stone for the jetty rehabilitation and
revetment is based on barging from a Connecticut quarry to
the site where it will be rehandled. Construction of the
scour blanket at the outer end of each jetty will be
accomplished by floating plant.
36. ALTERNATIVES CONSIDERED: Two basic alternative plans
were studied to provide navigation improvement at the Inlet:
(1) extend the east and west jetties 1400 ft. to el (-) 12
mlw to provide a sheltered area for navigation traffic and
(2) provide a stabilized navigation channel 200 ft. wide with
an alignment to allow for safe approach with minimum
operating depths of (-) 10 mlw by constructing a deposition
basin to envelope the navigation channel; this basin provides
for advanced maintenance to prevent channel infringement from
shoaling and thus afford stability to the navigation channel.
B7. Concerning the jetty extension plan, extension of the
east jetty would trap additional sand from the littoral
regime proceeding in the predominant direction to the west.
By interrupting this flow of sand, downdrift beaches would
suffer significant erosion. As mitigation, a fixed sand
bypassing plant, as envisioned in the authorizing document
plan, would be required to bypass trapped material. This
plant would consist of a steel pier, adjacent to and updrift
of the east jetty, supporting a dredge pump operated by
diesel engine and mechanically operated derrick mounted on a
rail car. The pump would be equipped with a suction pipe
which would be supported by the derrick over the east edge of
the pier. A discharge line connected to the pump would
extend along the pier, and across the Inlet to a feeder beach
approximately 5,000 ft to the west of the Inlet. The fixed
sand bypassing plant would operate approximately 200 days per
year and bypass approximately 300,000 c.y. of trapped sand
which is the approximate equivalent net littoral drift rate
to the west. The plan layout for this alternative is
displayed on Plate No. 7 with a typical section of the fixed
sand bypassing plant displayed on Plate No. 8. Minimal
maintenance dredging of the navigation channel between the
extended jetties would be required every 2 years. This
alternative however, was deleted due to its high cost, i.e.
total annual cost of $6,600,000 (detailed in Table B2A)
compared with between $3,400,000 and $4,400,000 for the
B2
alternatives utilizing the deposition basin. In addition,
the required pumping distance increase to approximately 9,000
L.F. as compared with 3,000 L.F. for the authorizing document
plan would pose additional mechanical reliability problems.
B8. Concerning the deposition basin plan, two alternative
channel design depths and three alternative deposition basin
widths and depths were analyzed to determine the most cost
effective channel depth and deposition basin size. The three
alternative basin dredge depths studied were (-) 18 mlw, (-)
20 mlw and (-) 22 mlw; the three alternative basin widths
studied were 500 ft., 700 ft. and 800 ft. and the two channel
depths studied were (-) 10 mlw & (-) 12 mlw.
B9. The initial construction costs and dredging maintenance
costs for the various alternative widths and depths are
developed in Tables B4 and B5, respectively. The maintenance
costs for the alternative plans displayed in Table B5
are based on the dredge requirements displayed in Table B2
which in turn are based on the shoaling rates developed in
paragraph C80 and Table C5 of Appendix C. Table B1 displays
the sum of the results of Tables B4 and B5 plus a $90,000
annual cost for stone maintenance to arrive at the total
annual costs for the plan alternatives. It is to be noted
that the interest rate used in screening alternatives is 8
5/8%. The recommended plan is updated to reflect an 8 7/8%
current interest rate.
B10. RECOMMENDED PLAN. Although the channel annualized
maintenance costs, as displayed in Table B5, for the
(-) 10 mlw channel depth with an 800 ft. wide basin
alternative for basin depths of (-) 20 mlw and (-) 22 mlw are
comparable, the (-) 20 mlw basin depth alternative is the
least costly due to the significantly higher initial
construction of the (-) 22 mlw basin alternative. This is
reflected in Table B1 for total annual costs. Therefore, the
selected plan based on cost effectiveness incorporates a
navigation channel through the Inlet offshore area of 200 ft.
width and (-) 10 mlw depth enveloped by a deposition basin
800 ft. wide to a depth of (-) 20 mlw.
B11. In addition to the features indicated in paragraph B1,
the recommended plan will include 3700 c.y. of initial
construction dredging at the fishing facility dock area to
assure necessary depths for navigability at currently shoaled
areas. This dredging would be accomplished by clamshell
dredge and disposed by barge and rehandled to the east of
the Inlet as part of jetty rehabilitation construction.
B12. ESTIMATED FIRST COST. The estimated project first cost
of the recommended plan is $12,185,600 which includes
dredging 552,000 c.y. for the construction of the deposition
basin and handling 90,000 tons of stone for the jetty
rehabilitation and revetment work. Also included is interest
B3
during construction for the jetty rehabilitation and
revetment work applied at the midpoint of construction or 10
month period. Excluding interest during construction, of the
$11,841,000 first cost, $9,203,000 is Federal apportionment.
Details of the first cost are presented in Table B3 with a
backup of detailed estimates of dredging cost displayed in
Table B6.
313. CONTINGENCY, ENGINEERING, DESIGN, SUPERVISION AND
ADMINISTRATION. A contingency of 20% is utilized for
initial construction which is in compliance with EM 1110-2-
1301 (31 July 1980) "Cost Estimates - Planning and Design
Stages". Engineering and design costs cover preconstruction
planning including preparation of the report and plans and
specifications in addition to engineering during
construction. Supervision and administration includes
supervision, overhead and inspection.
B14. CONSTRUCTION AND FUNDING SCHEDULE. The time schedules
for construction and expenditure of the recommended plan are
shown on Table B10 and are based on the timeliness of the
report's approval and allocation of funds by Congress, the
foregoing construction procedures and the ability of local
interests to implement the necessary items of local
cooperation, principally the furnishing of land, easements
and rights of way and the provision of a cash contribution.
It is to be noted that construction of the revetment will be
curtailed between April and August to preclude detrimental
environmental impacts to the species piping plover.
315. REAL ESTATE. The total area of land required for the
project as shown on Plate No. 6 consists of 80 acres of
permanent easement and 30 acres of temporary easement.
The entire acreage required is publicly owned with 75 acres
of permanent easement below mean high water. The non-Federal
interests shall provide the lands, easements, rights-of-way,
relocations (other than utility relocations) and dredged
material disposal areas necessary for the project. The value
of lands, easements, rights-of-way, relocations, and dredged
material disposal areas shall be credited toward the payment
required. The Federal Government will not credit the locals
with lands that are under Federal ownership or control.
II - COMPARISON OF COST ESTIMATES
B16. COMPARISON OF GDM ESTIMATE WITH AUTHORIZED DOCUMENT
ESTIMATE AND LATEST PB-3. Changes in the current GDM
estimate from that of the authorizing document (H.D. No. 126)
and the latest approved P3-3 dated October 1986 are shown in
Table B9. The total estimated first cost of the GDM
recommended plan is $11,841,000 (excluding interest during
construction). This represents a decrease of $6,859,000
compared with the latest PB-3 estimate. The decrease is due
primarily to the deletion of the jetty extensions and the
B4
associated fixed sand passing
plant. The following paragraphs compare the changes by
feature of the GDM estimate with the latest PB-3 estimate.
Since the latest PB-3 estimate is generally reflective of the
authorizing document plan with cost updating, the PB-3
estimate will be representative of the updated authorizing
document plan.
B17. CHANNELS. The cost increase of $3,787,300 is due
primarily to the dredging of 552,000 c.y. for the channel
construction and deposition basin for advanced maintenance in
lieu of the 137,000 c.y. for channel construction only
reflected in the PB-3 estimate. It is to be noted that
existing channel depths for the GDM estimate are
substantially deeper than the channel depths on which the PB-
3 estimate was based; this held down the cost increase.
B18. JETTIES. The cost decrease of $7,631,300 is due
primarily to deletion of the jetty extensions. Navigation
improvement as per GDM is to be afforded by stabilizing the
navigation channel with advanced maintenance in lieu of
creating a sheltered area between extended jetties.
B19. PERMANENT OPERATING EQUIPMENT. The decrease of
$2,510,000 is due to the deletion of the fixed sand bypassing
plant which was associated with the deleted jetty extensions.
Sand bypassing as per GDM is to be accomplished by hydraulic
dredge.
B20. ENGINEERING AND DESIGN. The decrease of $258,000 is
primarily due to a decrease in the scope of work for the
project improvement.
B21. SUPERVISION AND ADMINISTRATION. The decrease of
$107,000 is due primarily to a decrease in the scope of work
for the project improvement.
III - ANNUAL CHARGES
B22. GENERAL. The estimates of annual charges (for
comparison purposes) for all alternatives are based on a
useful project life of 50 years and an interest rate of 8
5/8%. The annual charges include interest and amortization,
periodic maintenance of the channel offshore of the Inlet
entrance and the fish facility dock area and maintenance of
the jetties and revetment. Table B7 however, summarizes the
estimated annual charges for the recommended plan at 8 7/8%
interest rate.
B23. PERIODIC DREDGING OF DEPOSITION BASIN. Periodic
dredging of the deposition basin is required for advanced
B5
maintenance of the channel. This dredging is recommended to
be accomplished by a 27" hydraulic dredge. Based on the
shoaling rate developed in Appendix C for the recommended
plan of an 800 ft. wide basin to an elevation of (-) 20 mlw,
the basin requires 456,000 c.y. of dredging every 1.5 years
to prevent channel infringement. Of the 456,000 c.y., 92,000
c.y. ( the prorated annual amount of 61,000 c.y.) is to be
placed just to the west of the Inlet on the beach front to
counter the significant erosion rate at this location and
thus stabilize this beach section to preclude a breach (refer
to paragraph C34 of Appendix C). The remaining 364,000 c.y.
of dredged material is to be pumped a mile to the west and
discharged just offshore to allow this material to continue
in the littoral system. A nodal point exists along the
shoreline a mile to the west of the Inlet so that placement
of dredged material closer than a mile could allow for some
of this material to return to the deposition basin area.
B24. Based on our experience with other Inlets on the South
Shore of Long Island, it is recognized that dredged channels
through bars tend to shoal rapidly. It is for this reason
that the recommended plan provides for a deposition basin
enveloping the channel that is large enough to handle the
rapid shoaling without channel infringement. Maintenance of
a channel, limited to the project channel dimensions only
without a deposition basin, is not only more costly, but is
impractical due to the frequency with which maintenance
dredging would have to take place, i.e., to ensure project
dimensions would require maintenance dredging on the average
of once every 2 months at an estimated cost of $1.2 million
per operation or $7.2 million per year. This compares
unfavorably with the estimated maintenance cost of $2.285
million associated with the recommended plan and therefore a
channel only plan was not developed.
B25. PERIODIC DREDGING OF THE FISHING FACILITY DOCK AREAS.
Currently shoaled areas in the dock area of the fishing
facility are anticipated to require maintenance for better
navigability at the fishing facility on the bay side just
west of the Inlet. The estimated maintenance dredging is
1,000 c.y. to be accomplished every 2 years by clamshell
dredge and disposed on an adjacent beach in the vicinity of
the Inlet utilizing dragline rehandling.
B26. STONE STRUCTURE MAINTENANCE. Annual maintenance cost
for stone structure maintenance is based on 2% of the
estimated first cost of the east and west jetties and 1 % of
the first cost of the new 1,000 ft. long revetment.
Customarily, annual maintenance of a Corps designed stone
structure is estimated to be 0.5% of its first cost where no
B6
Revised March 1988
records are available to establish required maintenance
costs. Since the existing jetties do not comply with Corps
design criteria, but can sustain acceptable damage levels,
the maintenance of the jetties has been increased to the 2%
indicated to allow for higher damage levels than anticipated
with Corps design criteria. The new revetment has been
designed utilizing Corps criteria with the possible condition
of structure submergence with design project hurricane
occurrence. Therefore a 1 % of first cost is used for an
annual maintenance cost.
B27. ANNUAL CHARGES. Total annual charges, as summarized in
Table B7, for the recommended plan, using an interest rate of
8 7/8% with a 50 year project life is $3,480,500.
IV - APPORTIONMENT OF COSTS BETWEEN INTERESTS
B28. GENERAL. The apportionment of the first costs of the
considered improvements between Federal and non-Federal
interests are based on the present policy governing
navigation improvements. The basis for apportioning the
costs involved is described in the following paragraph.
Details are given in Table B8.
B29. APPORTIONMENT. Federal policy provides for
apportioning the first cost of navigation improvements on a
Federal and non-Federal basis for recreational benefits and a
Federal apportionment for commercial benefits. The
navigation improvement will accrue, both recreational and
commercial benefits (as developed in the Benefits Appendix)
which results in a first cost apportionment of 71% Federal
and 29% non-Federal. Maintenance cost for commercial only
apportionment is 100% Federal. This results in the total cost
apportionment for maintenance of 71% Federal and 29% non-
Federal.
V - DEVELOPMENT OF ALTERNATIVE CONSTRUCTION METHODS
B30. GENERAL. Alternative methods initially considered for
constructing and maintaining the channel with its deposition
basin include use of the following: hopper dredge with pump
out capacity, clamshell and dipper dredges, fixed sand
bypassing plant, and the jet pump sand bypassing system also
known as the "Eductor System".
B31. OTHER DREDGING PLANTS CONSIDERED. A hopper dredge with
pump out capacity would be suitable for the dredging
construction required, however, plant availability is better
for a 27" hydraulic dredge, the selected plant.
B7
SUPPORTING DOCUMENTATION
APPENDIX
TITLE
A
PERTINENT CORRESPONDENCE (Contained in Main
Report)
A1
COMMENT RESPONSE SECTION (Contained in Main
Report)
B
COST ESTIMATE
C
ENGINEERING AND PROJECT DESIGN CONSIDERATIONS
D
STONE STRUCTURAL REHABILITATION AND REPAIR
E
BENEFIT EVALUATION
F
FISH AND WILDLIFE RESOURCE INVENTORY
332. Clamshell or dipper dredge would operate on a spudded
floating plant to anchor against the rough ocean environment
during its operation and deposit material, taken from the
basin, onto a tug drawn split hull type SCOW for delivery to
the disposal area - offshore to the beach one mile west of
the Inlet in 10 to 12 foot deep water. the operation of this
dredge in the ocean environment is considered impractical and
highly inefficient. This dredge can only operate in seas
with waves less than about one foot high; since this wave
height is exceeded much of the time, the dredge would require
a significant amount of down time. In addition, the
production rate of such a dredge would be less than 2,000
c.y. per day compared to approximately 13,000 c.y. per day
for the hopper and hydraulic dredges. Costs were not
developed for this alternative.
B33. The Fixed Sand Bypassing Plant consists of a
permanently mounted dredge on the east (updrift) jetty which
would pump up material from the required area and pump it
across the Inlet onto the beach on the downdrift side of the
Inlet. This plant has a limited range from where material
can be pumped. Because the deposition basin extends to 1800
feet oceanward of the end of the east jetty, the plant cannot
be utilized since much of the basin lies outside of the
dredge's range.
B34. The Jet Pump Sand Bypassing System consists of a water
pump permanently mounted on land that supplies water under
pressure through a submerged pipe to jet pumps which are
buried under the area to be excavated; the jet pumps then
suck in the sand to be removed with the incoming water under
pressure to form a slurry which is pumped through another
submerged pipeline to booster pumps back on land and then
pumped to disposal site on the beach. The disadvantage of
this system is that the distance between the jet pump and
booster pump should be no more than approximately 600 ft.,
the maximum jet pumping distance. This system cannot be used
at this location since the jet pump to booster pump distance
reaches a maximum of some 2,600 ft.
B8
TABLE B1
ALTERNATIVE CHANNEL/BASIN SIZES (a) (b)
TOTAL ANNUAL COSTS
CHANNEL DESIGN DEPTH (MLW) /
ALTERNATIVE BASIN WIDTH (FT)
BASIN DREDGE DEPTH (MLW)
500
700
800
10/18
$3,916,700
$3,761,900
$3,709,400
10/20
$3,572,300
$3,470,000
$3,439,400
10/22
$3,572,700
$3,512,000
$3,535,500
12/18
$4,418,500
$4,130,600
$4,055,400
12/20
$3,873,800
$3,719,400
$3,679,300
12/22
$3,787,900 $3,704,300 $3,696,700
a
Developed for an interest rate of 8 5/8% for a 50 year project
life.
b
Excludes non-Federal dredging.
B9
TABLE B2
DEPOSITION BASIN - INITIAL CONSTRUCTION VOLUMES
AND MAINTENANCE DREDGING REQUIREMENTS OF
CHANNEL ALTERNATIVES
CHANNEL DESIGN
INITIAL
ALTERNATIVE BASIN WIDTH(FT)
DEPTH (MLW) / BASIN
CONSTRUCTION/
500
700
800
DREDGING DEPTH (MLW)
MAINTENANCE
DREDGING (a)
10/18
INITIAL
295,300
379,100
418,500
CONSTRUCTION
C.Y.
C.Y.
C.Y.
MAINTENANCE
213,000
293,000
332,000
REQUIREMENTS
C.Y.
C.Y.
C.Y.
every 0.7
every 1.0
every 1.2
years
years
years
10/20
INITIAL
382,000
496,000
552,000
CONSTRUCTION
C.Y.
C.Y.
C.Y.
MAINTENANCE
294,000
402,000
456,000
REQUIREMENTS
C.Y.
C.Y.
C.Y.
every 1.0
every 1.3
every 1.5
years
years
years
10/22
INITIAL
475,400
620,600
691,800
CONSTRUCTION
C.Y.
C.Y.
C.Y.
MAINTENANCE
387,000
527,000
597,000
REQUIREMENTS
C.Y.
C.Y.
C.Y.
every 1.3
every 1.7
every 1.9
years
years
years
12/18
INITIAL
295,300
379,100
418,500
CONSTRUCTION
C.Y.
C.Y.
C.Y.
MAINTENANCE
175,000
240,000
273,000
REQUIREMENTS
C.Y.
C.Y.
C.Y.
every 0.6
every 0.8
every 0.9
years
years
years
(a)
Dredging cycles shown are rounded to the nearest tenth of a
year.
B10
TABLE B2 - (CONTINUED)
DEPOSITION BASIN - INITIAL CONSTRUCTION VOLUMES
AND MAINTENANCE DREDGING REQUIREMENTS OF
CHANNEL ALTERNATIVES
CHANNEL DESIGN
INITIAL
ALTERNATIVE BASIN WIDTH (FT)
DEPTH (MLW) / BASIN
CONSTRUCTION/
500
700
800
DREDGING DEPTH (MLW)
MAINTENANCE
DREDGING (a)
12/20
INITIAL
382,000
496,000
552,000
CONSTRUCTION
C.Y.
C.Y.
C.Y.
MAINTENANCE
255,000
350,000
397,000
REQUIREMENTS
C.Y.
C.Y.
C.Y.
every 0.8
every 1.1
every 1.3
years
years
years
12/22
INITIAL
475,400
620,600
691,800
CONSTRUCTION
C.Y.
C.Y.
C.Y.
MAINTENANCE
347,000
475,000
539,000
REQUIREMENTS
C.Y.
C.Y.
C.Y.
every 1.1
every 1.4
every 1.6
years
years
years
(a) Dredging cycles shown are rounded to the nearest tenth of a
year.
B11
TABLE B2A
Total First Cost and Total Annual Cost for the Jetty Extension
with Fixed Sand Bypassing Plant Alternative.
I. First Costs:
a) Jetty Rehabilitation & new revetment (1)
$ 6,100,000
b) Initial Bypassing (2)
$ 7,935,000
c) Stonework for Jetty Extension (3)
$25,170,000
d) Fixed Bypassing Plant @ East Jetty (4)
$ 6,918,000
e) Navigation Channel Dredging (to el-14 mlw) (5) $ 2,000,000
f) Interest During Construction (2 yrs.)
$ 4,630,000
Total First Cost
$52,753,000
II. Annual Costs:
a) Annualized First Cost (6)
$ 4,624,000
b) Annual Channel Maintenance (7)
$ 700,000
c) Annual Fixed Bypassing Maintenance and Pumping
Costs
$ 880,000
d) Stone Maintenance
$ 340,000
e) Non-Federal Maintenance @ Dock Facility
$
9,000
Total Annual Cost
$ 6,553,000
Rounded
$ 6,600,000
1) From Table B3.
2) Based on bypassing 2 years of drift (600,000 c.y) for
trapped material during construction of jetty extensions.
3) From Table B2C.
4) From Table B2B.
5) 150,000 c.y. of dredging required.
6) Based on n=50 years for 8 5/8% interest rate.
7) Based on Shoaling rate developed in authorizing document
(20,000 c.y./yr.) for 2 years, or 40,000 c.y. (60,000 c.y.
incl. overpumping).
B12
TABLE B2B
Detailed Estimat of Fixed Bypassing Plant (Dollars)
Estimated
Unit
Estimated
Description
Quantity
Unit
Price
Amount
I.
Steel Pier
Mobil. & Demobil.
-
Job
L.S.
$
125,000
Falsework & Footbridge
-
Job
L.S.
$
60,000
Steelpiles - vertical
7,000
L.F
$37.50
$
262,500
Steelpiles - battered
4,000
L.F.
$44
$
176,000
Structural Steel
800
Tons
$2,500
$2,000,000
Aluminum Floor Crating
15,000
S.F
$12
$
180,000
Railing & buffer
I
Job
L.S.
$ 20,000
Miscellaneous Steel
60
Tons
$2,800
$
168,000
Timber wales 10"x10"
4,000
L.F.
$12
$ 48,000
Timber fenders 10"x10"
1,500
L.F.
$12
$ 18,000
Concrete encasement
7,000
L.F.
$15
$
105,000
Subtotal
$3,162,500
II. Pumps, Engines, Rail Car & Equipment
Dredge pumps
1
ea.
$60,000
$
60,000
Booster pumps
1
ea.
$40,000
$
40,000
Diesel engine
1
ea.
$85,000
$ 85,000
Jet pump
1
ea.
$50,000
$
50,000
Derrick 25'boom (15'most)
1
ea.
$ 7,000
$
7,000
Hoist - 6 ton capacity
1
ea.
$17,000
$
17,000
14" dia. suction flexpipe
w/nipples & flanges
50
L.F.
$320
$
16,000
14" dia. Steel pipe
20
L.F.
$30
$
600
14" dia. flanged steel angle
2
ea.
$300
$
600
4" dia. suction hose
w/ couplings
100
L.F.
$20
$
2,000
Miscellaneous piping
-
Job
L.S.
$
6,000
Monorail hoist track
500
L.F.
$17
$
8,500
2-ton monorail electric
hoist w/motor driven trolley
1
ea.
$15,000
$
15,000
Rail car
-
Job
L.S.
$
60,000
Track
5,000
L.F.
$40
$
200,000
Car towing system
-
Job
L.S.
$
50,000
Cables, ropes, etc.
-
Job
L.S.
$
5,000
Galvanized sheet metal shell
w/timber framing for car
-
Job
L.S.
$ 17,000
Subtotal
$
639,700
III. Discharge Pipe Line
14" dia. steel pipe
8,000
L.F.
$70
$
560,000
14" dia. steel submerged
pipe
1,000
L.F.
$70
$
70,000
14" dia. armored flex. pipe
50
L.F.
$320
$
16,000
Dresser couplings
500
ea.
$210
$ 105,000
B13
TABLE B2B (Con't)
Detailed Estimated of Fixed Bypassing Plant (Dollars)
Estimated
Unit
Estimated
Description
Quantity
Unit
Price
Amount
III. Discharge Pipe Line (Con't)
12" steel T sections
20
ea.
$400
$
8,000
Miscellaneous hose &
pipe connections
-
Job
L.S.
$
7,000
Subtotal
$
766,000
IV. Electrical Lines
Power line
3,000
L.F.
$10
$ 30,000
Monorail hoist
conductors
1,000
L.F.
$25
$ 25,000
Communication devices
& lines
-
Job
L.S.
$ 45,000
Rail insulators
-
Job
L.S.
$ 10,000
Cable power supply
-
Job
L.S.
$ 50,000
Pier lighting
-
Job
L.S.
$ 40,000
Subtotal $ 200,000
V.
Fuel Storage Tanks
15,000 gallon tank and
accessories
-
Job
L.S.
$ 15,000
5,000 gallon tank and
accessories
-
Job
L.S.
$
Fuel lines
6,000
-
Job
L.S.
$ 15,000
Subtotal
$ 36,000
Subtotal I,II,IV, & V
$4,804,200
Contingencies (20%)
$ 960,000
$5,765,000
Eng., Des., Supp. & Adminstration (20%)
$1,153,000
Total Fixed Bypassing Plant
$6,918,000
B14
TABLE B2C
Detailed Estimated Stone Work For Jetty Extension Plan
Estimated
Unit
Estimated
Description
Quantity
Unit
Price
Amount
Capstone (10-12 ton)
219,000
tons
$52
$11,388,000
Corestone
120,000
tons
$40
$ 4,800,000
Bedding Stone
50,000
tons
$37
$ 1,850,000
Mob. & Demob.
-
Job
L.S
$ 200,000
Subtotal
$18,238,000
Contingency (20%)
$ 3,648,000
$21,886,000
Eng., Des., Sup., & Administration
(15%)
$ 3,284,000
Total
$25,170,000
B15
TABLE B3
SUMMARY OF INVESTMENT COSTS - RECOMMENDED PLAN
ESTIMATED
UNIT
ESTIMATED
ITEM
DESCRIPTION
QUANTITY
PRICE
AMOUNT
1.
Dredging-Channel/
Deposition Basin
(a)
to El -20 mlw
552,000 c.y.
$7.41/c.y.
$4,089,400
2.
Repair of East Jetty
a. 420 ft. armor stone
7,300 tons
$57/ton
$416,100
b. 420 ft. corestone
4,000 tons
$45/ton
180,000
c. remove and replace
730 ft. armor stone
12,600 tons
$30/ton
378,000
d. remove & replace
730 ft. core stone
7,200 tons
$30/ton
216,000
e. new armor stone
1,000 tons
$57/ton
57,000
f. new core stone
500 tons
$45/ton
22,500
g. Replace N.E. Revetment
260 ft. armor stone
2,340 tons
$45/ton
105,300
260 ft. core stone
1,300 tons
$45/ton
58,500
filter cloth
1,600 s.y.
3.5/s.y.
5,600
h. regrading beach
12,000 c.y.
$7/c.y.
84,000
at east jetty
i. Sand Fill
large north breach
19,000 c.y.
small pond area
4,000 c.y.
23,200 c.y.
$5/c.y.
116,000
J. Scour Blanket
16,000 tons
$57/ton
912,000
3. Repair of West Jetty
a. remove and replace
capstone & corestone 4,500 tons
$35/ton
$157,500
b. additional capstone
1,700 tons
$62/ton
105,400
C. additional corestone.
900 tons
$50/ton
45,000
d. scour blanket
10,000 tons
$57/ton
570,000
4. Mobilization and
demobilization
85,000
subtotal
$3,513,900
5. Construction of Bay Revetment
a. 1000 ft.-
revetment stone
9,900 tons
$40/ton
b. filter cloth
$396,000
11,700 sq. yds.
$3.5/s.y.
41,000
C. sand fill in bay
56,000 c.y.
$8/c.y.
448,000
subtotal
$885,000
B16
TABLE B3 - (CONTINUED)
SUMMARY OF INVESTMENT COSTS - RECOMMENDED PLAN
ESTIMATED
ITEM
DESCRIPTION
AMOUNT
6. Subtotal-Rehab & Revetment
$4,398,900
7. Subtotal - Dredging & Stone Work
$8,488,300
8. Contingencies (20%)
$1,697,700
9. Subtotal
$10,186,000
10. Engineering and Design
$820,000
11. Supervision and Administration
$790,000
12. Interest during Construction
$344,600
13. Total
$12,140,600
14. Non-Federal Dredging at Fishing Facility
a. 3700 c.y. at $9.00/c.y.
$33,300
b. Contingency 20%
6,700
C. Engineering, Design, Supervision & Admin.
5,000
Total Non-Federal Dredging
$45,000
15. Total Project First Cost
$12,185,600 *
(a) Excludes contingency, includes $500,000 for mobilization and
demobilization and a $6.50/c.y. unit price for production.
* The above table does not include the estimated value for lands,
easements, and rights-of-way for non-Federal publically owned
land, since there will be no actual cash outlay for these lands by
the local sponsor.
B17
TABLE B4
ALTERNATIVE CHANNEL/BASIN SIZES
TOTAL FIRST COSTS (EXCLUDING NON-FEDERAL DREDGING)
CHANNEL DESIGN DEPTH (MLW) /
BASIN DREDGE DEPTH (MLW) /
INITIAL CONSTRUCTION
INITIAL CONSTRUCTION COST-
TOTAL
DEPOSITION BASIN WIDTH (FT)
DREDGING COST (a)
JETTY REHAB. & REVETMENT
E&D + S&A
FIRST COST
10/18/500 & 12/18/500
295,300 c.y. @ $11.03/c.y.=$3,257,200
$5,623,300
$1,585,000
$10,465,500
10/18/700 & 12/18/700
379,100 c.y. @ $10.58/c.y.=$4,010,900
$5,623,300
$1,595,000
$11,229,200
10/18/800 & 12/18/800
418,500 c.y. @ $10.43/c.y.=$4,365,000
$5,623,300
$1,605,000
$11,593,300
10/20/500 & 12/20/500
382,000 c.y. @ $ 9.37/c.y.=$3,579,400
$5,623,300
$1,595,000
$10,797,700
10/20/700 & 12/20/700
496,000 c.y. @ $ 9.01/c.y.=$4,469,000
$5,623,300
$1,605,000
$11,697,300
10/20/800 & 12/20/800
552,000 c.y. @ $ 8.89/c.y.=$4,907,300
$5,623,300
$1,610,000
$12,140,600
10/22/500 & 12/22/500
475,400 c.y. @ $ 9.06/c.y.=$4,307,100
$5,623,300
$1,605,000
$11,535,400
10/22/700 & 12/22/700
620,600 c.y. @ $ 8.77/c.y.=$5,442,700
$5,623,300
$1,625,000
$12,691,000
10/22/800 & 12/22/800
691,800 c.y. @ $ 8.67/c.y.=$5,998,000
$5,623,300
$1,635,000
$13,256,300
(a) Includes mobilization & demobilization
B18
TABLE B5
ALTERNATIVE CHANNEL/BASIN SIZES
ANNUALIZED DREDGING MAINTENANCE COSTS (EXCLUDING NON-FEDERAL DREDGING
CHANNEL DESIGN DEPTH (MLW) /
BASIN DREDGE DEPTH (MLW) /
DREDGING MAINTENANCE COST
ANNUALIZING FACTOR @ 8 5/8% INT.
ANNUALIZED DREDGING
DEPOSITION BASIN WIDTH (FT)
PER OPERATION (a)
PRESENT WORTH X CAPITAL RECOVERY) (e)
MAINTENANCE COST (b)
10/18/500
213,000 c.y. @ $10.18/c.y.=$2,168,300 (c)
(15.15) (0.08765)
$2,909,200
10/18/700
293,000 c.y. @ $ 9.45/c.y.=$2,768,800 (c)
(10.95) (0.08765)
$2,687,400
10/18/800
332,000 c.y. @ $ 9.22/c.y.=$3,061,000 (c)
( 9.59) (0.08765)
$2,603,000
10/20/500
294,000 c.y. @ $ 8.44/c.y.=$2,481.400 (d)
(11.52) (0.08765)
$2,535,600
10/20/700
402,000 c.y. @ $ 7.92/c.y.=$3,183,800 (d)
( 8.33) (0.08765)
$2,354,500
10/20/800
456,000 c.y. @ $ 7.75/c.y.=$3,534,000 (d)
( 7.28) (0.08765)
$2,285,000
10/22/500
387,000 c.y. @ $ 7.97/c.y.=$3,084,400 (d)
( 9.03) (0.08765)
$2,471,300
10/22/700
527,000 c.y. @ $ 7.58/c.y.=$3,994,700 (d)
( 6.51) (0.08765)
$2,309,400
10/22/800
597,000 c.y. @ $ 7.45/c.y.=$4,447,600 (d)
( 5.78) (0.08765)
$2,283,300
12/18/500
175,000 c.y. @ $11.01/c.y.=$1,926,700 (c)
(20.02) (0.08765)
$3,410,900
12/18/700
240,000 c.y. @ $ 9.88/c.y.=$2,371,200 (c)
(14.56) (0.08765)
$3,056,100
12/18/800
273,000 c.y. @ $ 9.59/c.y.=$2,618,100 (c)
(12.72) (0.08765)
$2,949,000
12/20/500
255,000 c.y. @ $ 8.74/c.y.=$2,228,700 (d)
(14.37) (0.08765)
$2,837,100
12/20/700
350,000 c.y. @ $ 8.13/c.y.=$2,845,500 (d)
(10.32) (0.08765)
$2,603,900
12/20/800
397,000 c.y. @ $ 7.94/c.y.=$3,152,200 (d)
( 9.03) (0.08765)
$2,524,900
12/22/500
347,000 c.y. @ $ 8.14/c.y.=$2,824,600 (d)
(10.73) (0.08765)
$2,686,500
12/22/700
475,000 c.y. @ $ 7.70/c.y.=$3,657,500 (d)
( 7.71) (0.08765)
$2,501,700
12/22/800
539,000 c.y. @ $ 7.56/c.y.=$4,074,900 (d)
( 6.76) (0.08765)
$2,444,500
(a) Includes $500,000 mobilization & demobilization $70,000 E&D + S&A.
(b) Includes $30,000 annualized cost of monitoring program ($100,000/yr. for first 6 years of project).
(c) Based on a $7.50/c.y. unit price.
(d) Based on a $6.50/c.y. unit price.
(e) Based on Table B2.
B19
TABLE B6
DETAILED ESTIMATE - INITIAL CONSTRUCTION
OF RECOMMENDED PLAN FOR DREDGING
ITEM
QUANTITY
1. Estimated quantities to be removed
a. Total pay yardage
552,000 c.y.
b. Pay yardage removed
552,000 c.y.
C. Non-pay yardage
110,000 c.y.
d. Total yardage removed
662,000 c.y.
2. Output of dredge - c.y./day
13,000
3. Effective working days/month
18
4. Output of dredge - c.y./month
234,000
5. Job duration - months
2.83
6. Total monthly operating cost of dredge - $ 910,000
7. Total cost of job - $
2,575,300
8. Material and construction costs - $
57,000
9. Field engineering and supervision - $
80,400
10. Distributed costs (taxes, ins, SOC sec, etc. ) 171,700
11. Contractor's overhead, 12% - $
346,100
12. Bond cost - $ (1%)
32,300
13. Profit, 10% - $
326,300
14. Total contract cost
3,589,100
15. Estimated cost ($)/c.y. (14/lb)
6.50
16. Revised total contract cost (15 X 1a) - $3,588,000
17. Mobilization and demobilization - $
500,000
18. Total direct cost -$
4,088,000
19. Contingency, 20% - $
817,600
20. Subtotal - $
4,905,600
21. Engineering & Design -$
383,000
22. Supervision &. Administration -$
392,000
23. Total - $
5,680,600
B20
TABLE B7
TOTAL ANNUAL COST - RECOMMENDED PLAN
ITEM
DESCRIPTION
ANNUAL COST FOR
INTEREST RATE OF 87/8%
1.
Annualized First Cost of
$12,185,600 (a)
$1,097,100 (c)
2.
Deposition Basin Maintenance
per operation - 456,000 c.y.
@ $7.75/c.y. (b): = $3,534,000.
$2,284,400 (d)
3.
Jetty Maintenance
$90,000
4.
Non-Federal Dredging Maintenance
at Fishing Dock Facility (e)
$9,000
5.
Total Annual Cost
$3,480,500
(a) From Table B3
(b) Based on a production unit cost of $6.50/c.y (refer to
Table B6), $500,000 for mobilization and demobilization
and $70,000 for engineering, design, supervision and
administration.
(c) Utilizing a CRF of 0.09003.
(d) Utilizing a PWF of 7.085 (dredging cycle from Table B2)
a CRF of 0.09003 and $30,000 for annualized monitoring
costs.
(e) Based on dredging 1,000 c.y. every 2 years with a
clamshell dredge.
B21
TABLE B8
APPORTIONMENT OF COSTS
RECOMMENDED PLAN
October 1986
Price Level
First Cost
Federal
$ 9,203,000
Non-Federal
2,638,000
Total
11,841,000
Annual Maintenance, Operations and
Replacement
Federal
$ 1,691,000
Non-Federal
692,000
2,383,000
B22
TABLE B9
UNIFORM FEATURE BREAKDOWN OF ESTIMATE OF FIRST COST
House Document
Latest. PB-3
General Design
Difference Between
Difference Between
Account Number
No. 126
(October 1986)
Memorandum
H.D. and GDM
PB-3 and GDM
09 Channels
$378,500
$1,160,000
$4,947,300
+$4,568,800
+$3,787,300
10 Jetties
$4,202,900
$12,910,000
$5,278,700
+$1,075,800
-$7,631,300
20 Permanent Operating
Equipment
$650,600
$2,510,000
-$650,600
-$2,510,000
30 Engineering
and Design
$48,500
$1,080,000
$822,000
+$773,500
-$258,000
31 Supervision and
Administration
$317,500
$900,000
$793,000
+$475,500
-$107,000
Total Cost
(COE and Non-Federal
Contribution)
$5,598,000
$18,560,000
$11,841,000
+$6,243,000
-$6,719,000
Total COE Cost
$3,529,000
$11,500,000
$9,203,000
+$5,674,000
-$2,297,000
Total
Non-Federal Cost
$2,069,000
$7,060,000
$2,638,000
+$ 569,000
-$4,422,000
Summary of Estimated Costs
Federal Cost
Corps of Engineers
$3,529,000
$11,500,000
$9,203,000
+$5,674,000
-$2,297,000
Coast Guard
$40,000
$140,000
0
-$40,000
-$140,000
Non-Federal Costs
$2,069,000
$7,060,000
$2,638,000
+$ 569,000
-$4,422,000
Total Federal and Non-Federal Cost
$5,638,000
$18,700,000
$11,841,000
+$6,203,000
-$6,859,000
B23
TABLE BIO CONSTRUCTION: AND EXPENDITURE 56
HEDU
LE
DOLLA
R57
OCT.
1985
PRIE
EYEV
ELS
Prior.
1986
1987
1988
1989
1990
RECOMMENDED PLAN
Years
4
IFAIS
aINID
ЛАМА MIX
A15
al
NID
TAMAM
2241
OMP
ITEM
AMIZE
Also
INDIA
EMAMIT!
A
TOTALS
FY1987
FX1988
FY
9891
AY1990
570,000
155,000
Preparation of Final GDM
33,000
42,000
Preparation of Plans E Specification
Review Approval f Plans F Specification
Advertise, Open f Evaluate Bids
11,000
11,000
623|000
823
000
Engineering During Construction.
176,000
12,000
12,000
375,000
218,000
793,000
Supernsion, Inspection #Administration
4947300
4,947,300
of Depositra Barry Char
& Dredging at Fishing Each #
Stone Construction- Rehabilitation of
2,970,000
2308,700
5278,700
East and West. Jeffres & Revetment
TOTAL EXPENDITURES
746,000
200,000
54,000
8,303,300
2,537.700
11,841,000
TOTAL FEDERAL
746,000
200,000
54,000
6,282,700
1,920,300
9,203,000
TOTAL NONFEDERAL
0
01
D
2,020,600
617,400
2,638,000
B24
B24
APPENDIX C
ENGINEERING AND PROJECT DESIGN CONSIDERATIONS
APPENDIX C
ENGINEERING AND PROJECT DESIGN CONSIDERATIONS
TABLE OF CONTENTS
Description
Page
PART I ENGINEERING CONSIDERATIONS
DESCRIPTION OF PROJECT AREA AND VICINITY
1
Problem Identification
2
TIDES AND CURRENTS
2
General
2
Historical Bay and Ocean Tidal Current
W
Changes
Currents
W
CIRCULATION IN THE BAY
4
WINDS
5
WAVES
5
Existing Wave Climatology
6
LITTORAL PROCESSES
7
Littoral Materials
7
Littoral Drift
7
INLET HISTORY, HYDROGRAPHY, SHORELINE
8
AND VOLUMETRIC CHANGES
AND STABILITY CONSIDERATIONS
History
8
Hydrography
9
Channel Scour History
10
Volumetric Shoreline Changes Near
10
Shinnecock Inlet
Shoreline Changes Adjacent to
11-13
Shinnecock Inlet
Development of Offshore Bar and
13
Ebb Tide Delta
Development of Flood Tide Delta
13
Sediment Budget
14
STABILITY CONSIDERATIONS
15-16
Recent Maintenance Dredging at
16
Shinnecock Inlet
PART II - PROJECT DESIGN
INTRODUCTION
BASIS OF DESIGN
17
Design Criteria
17
17
Description of Proposed Structural Work
Pertinent Data on Existing Structures
18
STRUCTURAL DESIGN
18-20
General
20
20
i
PART II - PROJECT DESIGN (CON T)
Rehabilitation of West Jetty
20
Proposed Revetment Along Bay Shoreline
21
Repair of the East/West Jetty and Revetment
21
CHANNEL DESIGN
22
General
22
Design Criteria
22
Existing Navigation Conditions Fronting
23
the Inlet
Vessel Types and Sizes
23
Methodology of Channel Design - Design
23-24
Requirements
Description of Parameters -- Channel
24
Width
Channel Depth
24
Channel Alignment
24-25
Deposition Basin
25-26
Dredge Disposal Sites
26
Periodic Maintenance - Bay Channel
26
Periodic Maintenance - Inlet Channel
26
Periodic Maintenance - Ocean Entrance Channel 27
Application
27-28
Results
28
Effects of Channel Design on
28-29
Existing Inlet/Bay System
PART III - PROJECT MONITORING PROGRAM
General
29
Task I - Fill Placement
29-31
Task II - Borrow Area
31-32
Task III - Shoreline Change
32
Task IV - Biological Assessment
32
ii
REVISED
LIST OF TABLES
TABLE
TITLE
Page
C-1
Shinnecock Inlet and Bay
B
Tide Ranges
C-2
Estimated Average Annual Winds
34
C-3
Wave Data
35-36
C-4
Inlet Channel Cross-Sectional
Area (Below MLW) Changes
37
C-5
Shinnecock Inlet Throat Cross-
37
Sectional Area and Hydraulic
Changes
C-6
Shoreline Erosion West of the
38
Inlet
C-7
Deposition Basin Shoaling Rate
39
C-8
Sampling Schedule for Beach Fill
40
Monitoring
iii
LIST OF FIGURES
TABLE
TITLE
Page
C1
History of Bay Tide Range in
41
Shinnecock Bay
C2
Wind Diagram - South Shore of
42
Long Island
C3-1
Shinnecock Inlet Cross Section
43
Stationing
C3-2 to
Comparative Channel Cross
44-51
C3-9
Sections
C4
Beaches West of Shinnecock Inlet
52
C5
Shoreline Change Map
53
C6
Ebb and Flood Tidal Delta
54
Movement
C7
Shinnecock Inlet Sediment Budget
55
C8
Typical Hydraulic Stability Curve 56
C9
Shinnecock Inlet Stability
57
Analysis
C10
Recommended Channel Alignment and 58
Sediment Basin
C11
Monitoring Locations
59
iv
LIST OF COMPUTATIONS
COMPUTATION
DESCRIPTION
C1
Stability Analysis
C2
Design Wave Analysis -
Existing Design
C3
Design Current Velocity
C4
Design Wave Analysis - Depth
limited Wave Height
C5
Design Wave Height for
Proposed Revetment
C6
Channel Width Design
C7
Shoaling Analysis - Transport
Ratio Method.
<
ENGINEERING AND PROJECT DESIGN CONSIDERATIONS
INTRODUCTION
Part I of this appendix presents a description of the
characteristics of Shinnecock Inlet and Bay, and the adjacent
shoreline along the barrier beach. Part II discusses the
engineering and design of the alternative plans considered
and a description of the selected plan. Part III describes
the monitoring program.
PART I = ENGINEERING CONSIDERATIONS
DESCRIPTION OF PROJECT AREA & VICINITY
C1. Shinnecock Inlet is one of the 6 openings through the
narrow barrier island on the south shore of Long Island (see
plate 1 of the main text) which separates the Atlantic ocean
from the interior bays. It is located in the Township of
Southampton, Long Island, New York, 95 miles by water east of
the Battery, New York City, and 37 miles by water west of
Montauk Point. Four other inlets along the barrier beach are
Moriches, Fire Island, Jones and East Rockaway Inlets
located 15, 45, 60, and 70 miles, by water respectively, west
of Shinnecock Inlet. The sixth inlet, known as Rockaway
Inlet, is located at the western tip of the barrier island
and connects the Atlantic Ocean with Jamaica Bay. Seawater
of varying salinity prevails in the inlets and bays, and
therefore, these waters are not normally affected by ice
conditions. No harbor lines have been established in the
inlets and the bays.
C2. Shinnecock Bay, is about 9 miles long and has widths
ranging from 0.4 to 2.8 miles. The total water surface area
of Shinnecock Bay is 16 square miles. The bay drains about
20 square miles of land. Fresh water enters the bays from
the drainage area mainly through groundwater seepage and
river flow. The bay areas near mouths of tributary streams
are more brackish than other parts of the bays where mixing
with incoming ocean water through the inlets takes place more
readily. The bay extends from the village of Southampton on
the east to the village of Quoque on the west, where it
connects with Moriches Bay through the Quantuck and Quogue
Canals. The canals are about 200 feet wide and have a
surface area including Quantuck Bay of 2 square miles.
Quantuck Bay and the canals drain a land area of abcut 10
miles. Depths average about 6 feet, with maximum depths of
10 feet in Shinnecock Bay. Some locations in the Intercoastal
Waterway have depths greater than 20 feet. Numerous
tributaries indent the northern side of Shinnecock Bay, the
largest of which are Tiana Bay and Weesuk Creek, located in
the western portion. In the eastern portion, Shinnecock
Canal which was constructed by local interests, cuts through
a narrow neck of the mainland to Great Peconic Bay.
1
C3. Problem Identification
The development of the problems associated with the
existing channel has been previously discussed in the Main
Report. The problems and need for solution are reiterated
here to indicate the objective of the design for the proposed
dredging for the navigation channel at Shinnecock Inlet. The
objective of the design is to stabilize the inlet system
which includes the east and west jetties, the bay shoreline,
a deposition basin as well as the navigation channel.
The presence of an offshore bar system at. the oceanward
entrance to the inlet (some locations of shoaling are at -8
feet MLW) forces all channel users to take a circuitous
course, which runs in a southwestern direction from the inlet
jetties, subjects vessels to broaching ocean waves. The
shoal is migrating to the southwest across the inlet
infringing on the deep channel causing an unstable condition
of the channel including apparent width fluctuations.
Continued shoaling across the bar has increased the occurence
of breaking waves, limiting access to the inlet.
Jetty rehabilitation and the need for a bayshore
revetment are required for stability of the inlet system and
are discussed further in following paragraphs.
Continued shoaling of the inlet without periodic
maintenance will eliminate access to the inlet in the future
due to the growth and movement of the offshore bar. Without
repair and rehabilitation the jetties will continue to
deteriorate and are expected to fail in 10 years. The
proposed plan of improvement will address all aspects of the
inlet system.
TIDES AND CURRENTS
C4. General. Astronomical tides along the study area are
semidiurnal, flooding and ebbing twice a day. At the inlet
entrance, the mean ocean tide range is 2.9 feet and the
average spring tide range is 3.5 feet (Reference 1). These
tides are primarily the result of the gravitational forces of
the moon and sun, the centrifugal forces due to the movement
of the earth in its orbit, the Coriolis forces due to the
earth rotating about its axis, and frictional forces due to
the movement of the water with respect to its boundaries.
The theoretical astronomical tides are predictable; however,
the effects of offshore/onshore winds and atmospheric
pressure changes in depressing the theoretical high and low
tide levels or causing tide set-up and/or tide cycle lag are
not predictable. Mean Low Water is 1.27 feet below the
National Geodetic Vertical Datum of 1929 (NGVD).
2
C5. Wind tides or set-up are local phenomena and occur most
dramatically in shallow water. Wind set-up has a significant
effect on seasonal and long-term shoreline erosion. During
strong onshore winds, wind tides 2 to 3 feet are not
uncommon. Extremely high wind velocities coupled with very
low barometric pressures, tropical depressions or hurricane
conditions, have caused tides as high as 8.3 feet above mean
low water in Shinnecock Bay (9/12/60).
C6. Historical Bay and Ocean Tidal Changes. Tide
observations at a number of locations in Shinnecock Bay and
in the inlet have been made for varying periods since 1938 by
the Suffolk County Department of Highways and by the Corps of
Engineers. In January 1938, five gages were placed in the
bays and operated until 17 September 1938, just prior to the
hurricane of 21 September. In 1940, six tide gages were
installed for periods up to 12 months, in 1949 twelve gages
for a period of about 4 months, and in 1951 five gages for
about 2 months. Gages were also installed in the bays in
1956 by the Corps of Engineers in connection with pending
hurricane studies of this area and in 1967-68 to obtain
baseline data for the inlet model study. These observations
afford a record of the tidal characteristics and indicate the
changed characteristics during the varying conditions of the
inlets. Table C-1 excerpted from reference 2 gives a summary
of these records; however, tidal data obtained in 1967-68 is
continuous over only one tidal cycle and is not contained in
the table.
C7. A gage operated by Suffolk County, New York Department
of Public Works located in one of the public boat basins just
west of Shinnecock Inlet has been in operation since
1951. Examination of records kept for a tide gage at the
Shinnecock Inlet boat basin shows that a general rise in the
tide range on the bay side of the inlet between 1953, when
the jetties were constructed, and the early 1960's. This rise
is indicative of increased bay tide range as the inlet
stabilized. Beyond 1962, the bay tide range levels off,
indicating the stable condition of the inlet. Average bay
tide range is approximately 2.6 feet. Figure C-1 represents a
history of the bay tide ranges recorded at the Shinnecock
Inlet boat basin. The graph is a plot of mean quarterly
tidal ranges.
C8. Currents. The tidal currents in Shinnecock Inlet have
been measured by current meters and floats on a number of
occasions before and after construction of the jetties at the
Inlet. During recent years, there has generally been little
change in the average maximum velocities in the inlet which
range from about 3.9 feet per second to 4.2 feet per second
through the tidal cycle. Float observations have shown
maximum velocities as high as 8 feet per second. A more
complete treatment of earlier tidal current investigations
and flow determinations can be found in the documents listed
3
below. The findings of these investigations which are
germane to the bay circulation are discussed in paragraphs
C9 to C11.
(a) Survey Report, Moriches and Shinnecock Inlets 1958,
(Reference 3).
(b) Circulation Calculations in Shinnecock Inlet and
Vicinity (Reference 4).
CIRCULATION IN THE BAY
C9. Circulation. The circulation of water in Shinnecock Bay
is caused primarily by tidal currents. The ocean tide has a
mean range of 2.9 feet at Shinnecock Inlet. In the inlet,
the tidal wave has the character of a progressive wave, in
which slack water occurs near half tide when the level inside
and outside the bay is the same. Maximum flood and ebb
currents occur at about the time of high and low waters in
the ocean, when the difference in levels inside and outside
the bay is greatest (Reference 5). Because of the relatively
small size of the inlet and the shallowness of the bay, the
tidal wave is dampened and delayed in its passage. The range
of tide in the bay is consequently reduced (see figure C1),
and high water occurs progressively later at points more
remote from the inlet. The duration as well as the volume of
the ebb tide through the inlet is greater than the flood
tide, due to net inflow to the bays from adjacent bays. The
bay circulation described in the following paragraphs
generally describes the conditions which existed from 1958 to
present, and from 1938 to about 1951.
C10. The tidal currents due to the flow of water into and
out of the bay are strong in the restricted passages of the
inlet where maximum velocities of over 6.8 feet per second
occur. Within the bay velocities are lower. In general, the
movement in the bay has an east-west direction paralleling
the shores.
C11. Were Moriches and Shinnecock Bays and the adjoining
Great South Bay of the same size, shape and subject to
identical ocean tides, the tidal movement from each would
meet in the connecting passages and little exchange between
the bays would result. However, the bays are very different
in size and shape and some exchange through the connecting
passages occurs. At the Quantuck and Quogue Canals at the
western end of Shinnecock Bay, the tidal currents results
from differences in tide levels in Moriches and Shinnecock
Bays at the different periods in the tidal cycle. There is a
lag of 2 to 3 hours in the time of slack water as compared
with that at the inlets. The greater tidal range and the
earlier time of high water in Shinnecock Bay causes a
westward flow during the flood tide. The ebb flow, normally
4
of greater volume than the flood flow, is toward the inlet.
The canal which connects Moriches Bay and Shinnecock Bay is
small and the quantity of water that is usually conveyed is
consequently small when compared to the tidal prisms of
either bay. This is shown by a series of observations made
during 26 July to 4 August 1950 by the Woods Hole
Oceanographic Institution.
WINDS
C12. A study of recorded and possible wind velocities,
duration, and direction is necessary to determine their
effect on the characteristics of waves likely to be
experienced in the study area. Wind generated waves are the
primary natural forces shaping the ocean shoreline in the
study area. The design height of most shore structures is
dictated to a great degree by the height and force of such
waves likely to be experienced.
C13. Records of the United States Coast Guard and Suffolk
County Highway Department for the South Shore of Long Island
for the period of 1940-1959 were used in compiling the wind
diagram shown on Figure C2. The diagram indicates the
velocity in four velocity groups - the directions from which
the winds blew, and the duration in days. The diagram
indicates that the direction of the predominant onshore winds
is southwest. Table C2 gives the percent of time and
direction from which winds blow as indicated by those
records.
C14. Winds from the eastern and southern quadrants, although
not frequent, have an appreciable influence on the direction
of littoral drift on the south shore of Long Island, since
they blow over practically unlimited fetches of the open
ocean.
C15. Diagrams showing prevailing winds as compiled from
records of the U.S. Navy Hydrographic Office for the 5-degree
squares nearest the shore of Long Island are shown on Plate
2. These diagrams indicate that winds from the westerly
quadrants prevail, which is in agreement with the
observations shown above. The monthly cumulative average
winds over the North Atlantic, compiled from the records of
the Hydrographic Office, United States Navy (reference 6)
show the predominant direction of surface winds offshore to
be from the northwest from October through April and from the
southwest from May through September.
WAVES
C16. The wind waves that occur in the study area consist of
"sea" and "swell". Local seas are waves generated by local
winds and are observed as traveling with the wind. Swells
5
are waves generated from distant storms, as far away as 1,000
miles, that enter the study area independent of the local
wind conditions.
C17. Existing Wave Climatology. There are about 27 months
of local near shore wave data available from a pressure wave
gage installed in about 30 feet of water at Southampton, New
York, by U.S. Army Coastal Engineering Research Center
(CERC). Although this data appears to be of remarkable
quality, it does not provide information on wave direction,
accordingly it cannot be used for this report.
C18. Visual surf observations were made from the Short Beach
Lifeboat Station at the western end of Jones Beach for the
period of October 1954 to December 1957 under a cooperative
surf observation program between the U.S. Coast Guard and the
Beach Erosion Board. The results, are published in Technical
Memorandum No. 108 (reference 7), show that 98 percent of the
waves were from the southern quadrant and the remaining 2
percent were from the east. The waves from the southeast and
southwest predominated, with 41 percent and 40 percent of all
the waves coming from these directions, respectively. During
the period of observation, only 5 percent of the waves had a
height of 4 feet or greater. Additionally, onshore visual
wave observations of nearshore wave climatology are available
from the CERC Beach Evaluation Program (reference 2),
however, resolution of the observation into height and
direction statistics is not yet published.
C19. There are 4 sets of deep water wave statistics
available for the south shore of Long Island. These are the
hindcast statistics published by Neuman and James (reference
S), the hindcast statistics published by T. Saville, Jr.
(reference 9), and the Summary of Synoptic Meteorological
Observations (SSMO, reference 6) which are in part water
compilations of deep water wave observations for the entire
offshore zone along the south shore of Long Island, and the
U.S. Army Waterways Experiment Station, Wave Information
Study, Shallow Water.
C20. The wave data statistics chosen for this study was
taken from "Wave Information Study for the South Shore of
Long Island - Phase III -Station 46" (see Tables C4) which is
part of the Wave Information Studies of U.S. Coastlines
(Reference 10). The wave data developed in this study
consists of percent occurrence of significant wave heights
and period ranges typical for each 30 degree of wave angle
approach at a depth of 10m. gathered for 20 years of
hindcast.
C21. Table C3 reveals that the predominant 30 degree sector
of wave occurrence is for the wave angle sector between 60
and 89.9 degree. This sector corresponds to a compass
direction of 159 to 189 degree from true north, with the
6
midpoint of the sector at 175 degree azimuth (S5 degree E).
C22. The wave and swell conditions can also be described in
terms of their affect on navigability and safe inlet usage.
The existing conditions of wave and swell activity at
Shinnecock Inlet have been provided by a consensus of the
U.S. Coast Guard and local commercial inlet users. The
variety of these conditions can be described as calm, normal
and adverse in terms of navigability. In the recent past,
the shoaling fronting the inlet has increased heights of
breaking waves, limiting the access to the inlet for some
vessels especially at times of low tide, during normal wave
activity.
Continued shoaling without project improvements will
increase breaker activity further limiting inlet navigation.
A full description and the economic impact of these,various
conditions can be found in the Economic Appendix.
LITTORAL PROCESSES
C23. Littoral Materials. Evidence indicated that the
material comprising the barrier beaches is derived from the
erosion of the shore and headlands to the east, possibly
supplemented by material seasonally moved shoreward by
onshore waves and currents along the ocean bottom. Results of
mechanical sieve analysis show that the largest grain size of
beach material is at Montauk Point, where the median
diameter, based on samples taken at various times from 1936
to 1956, was found to vary from about 1 to 4 millimeters.
The median diameter decreases sharply, to about 0.4
millimeter, in the vicinity of Hither Hills State Park near
East Hampton, and does not vary appreciably from that size as
far westward as Fire Island Inlet, except in the areas
somewhat to the west of Shinnecock and Moriches Inlets, where
the median diameters of the 1955-56 samples increased
abruptly to 1.2 to 0.8 millimeters, respectively, and
probably show the effects of the heavy erosion that had taken
place in these areas. Such abrupt increases are not
indicated by the samples taken in prior years. In general,
the materials in the offshore zone were found to be finer
than the materials along the shore. The data show that,
progressing westward, the sand loses its heavy granitic,
feldspar and iron mineral content and becomes a purer quartz.
Information on textural characteristics of the channel will
be obtained during the proposed monitoring program. The
results will be presented in the yearly monitoring reports
(see para. C87).
C24. Littoral Drift. All available evidence indicates that
along the south shore of Long Island the net littoral
transport is from east to west. This is indicated by the
observed westward migration of the inlets. Fire Island Inlet
and Rockaway Inlet prior to stabilization, were reported by
Beach Erosion Board (TM 128, reference 11) to have. migrated
7
westward at annual rates of 201 and 222 feet, respectively.
These rates as reported are based on a 100 year period of
record. The littoral transport rate estimated from these
inlet migrations is about 450,000 cubic yards per year to the
west.
C25. The impounded materials on the beach side of the east
jetty and the associated degradation of shoreline on the
beach side of the west jetty at Shinnecock Inlet is further
evidence that the littoral transport has a marked westward
predominance.
C26. The net littoral transport rate adopted in the
authorized survey report for Shinnecock Inlet is 300,000
cy/yr to the west. A sediment budget study conducted for the
south shore of Long Island (Reference 12) was utilized to
confirm this transport rate. Within the boundaries of the
control volume used to analyze the amount of littoral
movement in the area (see Paragraph C37-Sediment Budget) it
is estimated that the gross (eastward and westward) transport
volume is about 400,000 cy/yr. This is the volume of
material which is expected to be available for entrapment in
a sedimentation basin. This volume was used in the
sedimentation analysis as stated in Paragraph C79.
INLET HISTORY, HYDROGRAPHY, SHORELINE AND VOLUMETRIC
CHANGES, AND STABILITY CONSIDERATIONS
C27. History. Charts of Long Island dating since Colonial
days indicate the existence from time to time of natural
openings through the barrier beach into Shinnecock Bay.
Although no continuous information is available, a map dated
about 1770 shows an inlet into Shinnecock bay. A survey made
by David H. Burr in 1829 records one inlet at the eastern
end of Shinnecock Bay. However, another survey made by Burr
10 years later indicates that this inlet had closed.
Openings into Shinnecock Bay appear on maps made during the
period 1850 to 1890. No inlets are shown from 1890 to 1938,
the year the existing inlet broke through.
C28. The present Shinnecock Inlet was formed as a result of
wave action and extremely high water caused by the hurricane
of 21 September 1938. In 1939 local interests constructed a
bulkhead 1,470 feet long on the west side of the inlet
consisting of two rows of closely driven timber piling with
the intervening space filled with riprap and sand and cement-
filled bags in galvanized wire cages. Twenty short spur
jetties were built normal to the bulkhead. A revetment of
the fill material was placed in front of the structure to
prevent its being undermined. The structure acted as a brake
to the tendency of the inlet to move westward. Subsequent
storms caused damage to the works, and in 1947 local
8
REVISE
interests repaired the stone revetment and added a 130 foot
stone groin on its northerly end. In 1952-53 local interests
constructed stone jetties on both sides of the inlet and in
1954 they extended the west jetty. In 1982, Suffolk County
Department of Public Works reconstructed the pile crib
revetment at the north end of the west jetty and part of the
west jetty in the inlet. The pile crib revetment was
replaced by a rubble mound jetty. Local interests
constructed a bay channel 10 feet deep and 200 feet wide from
a point inside the inlet to the Intracoastal Waterway in
1958, and widened it to 300 feet in 1963 and subsequently
performed maintenance operations in 1973 and 1978. In 1966
local interests dredged through a shoal area northwest of the
inlet and again in 1969 between the inlet and the
Intracoastal Waterways.
C29. The storm of 6-8 March 1962 produced unusually high
wind driven tides and high waves which continued to batter
the south shore of Long Island for three successive days. A
widespread pattern of waves travelling out of the storm
eventually affected virtually the entire east coast of the
United States. Because the storm was of such magnitude and
covered a large area and because of the scarcity of
observations over the ocean, it is difficult to plot a well-
defined path or show the location at any particular time.
Along the southern shoreline of Long Island between Fire
Island Inlet and Montauk there was damage to beaches, dunes,
groins, seawalls, paving and buildings as a result of high
waves and flooding. At Shinnecock Inlet the 1962 storm
caused bank erosion and jetty damage (stone displacement) on
the east jetty. The south end of the east jetty suffered
damage, and a jetty light was destroyed. The rehabilitation
of the jetties will strengthen them, making them more
resilient to storm damage.
C30. Hydrography. The physical changes at the inlet
described in the preceding sections have resulted in changes
in the hydrography of the inlet. It should be noted that the
the hydrography of the inlet is undergoing continual change
and, particularly during storms, considerable changes may
take place during very short periods.
C31. Based on Hydrographic information made available by the
U.S.C. & G.S. over the period of years from 1930 through 1955
together with other survey information, an interpretation of
historical hydrographic changes was made and is summarized
below. Prior to the breakthrough of Shinnecock Inlet in
1939, the barrier beach between the bay and the ocean was
continuous and a paved road crossed the present site of the
inlet. A shoal area in the bay 1 to 2 feet deep and about
3,000 feet wide extended parallel to the beach except for a
narrow channel which connected deep water in the bay with an
indentation in the barrier beach, indicating the probable
previous existence of a temporary inlet at this point. As
9
might be expected, the break through during the storm of 21
September 1938 occurred at this location. In 1939, the inlet
was 700 feet wide. During that year works were constructed
on the west side of the inlet which prevented its migration.
In 1941 the inlet had widened to the east to about 1,000
feet, an inner and outer bar had formed and a tortuous
channel connected the ocean with the bay. Although this
channel was as deep as 23 feet at one point, the controlling
navigable depth was only about 4 feet.
C32. During 1953-54, local interests constructed jetties on
both sides of the inlet. As a result, the inlet openings
which was perpendicular to the ocean shoreline rotated to
conform with the alignment of the jetties which were
constructed in a north-south direction. Just prior to
construction of the jetties, the inlet was about 500 feet
wide and had depths ranging from 3 to 6 feet. Two channels
connected the inlet with deep water in the bay. One channel,
dredged at the request of the U.S. Navy in 1943 to a depth of
6 feet and a width of 100 feet and which connected the inlet
to the Long Island Intracoastal Waterway near Ponquogue
Bridge, had shoaled to a controlling depth of about 5 feet.
The second channel, located at the east side of the inner
bar, had natural depths of 3 1/2 to 9 feet. After completion
of the jetties, the width of the inlet was fixed at 800 feet,
the distance between the jetties.
C32.1. Channel Scour History. Three inlet hydrographic
surveys were evaluated for the channel scour history - 1955-
56, June 1984, and June 1985. The 1955-6 survey can be
considered representative of the inlet immediately after
construction. Comparative cross sections were plotted at
eight locations as shown in Figures C3-2 to C3-9. The inlet
channel cross sectional areas at each location as well as
information on the inlet throat characteristics are provided
in Tables C4 and C5. The inlet has experienced significant
scour since the jetty construction in 1952. Cross sectional
areas have increased over 300% to achieve its current stable
configuration. The minor variation in area between 1984-1985
indicates the inlet is within its stable configuration.
C33. Volumetric Shoreline Changes Near Shinnecock Inlet. An
analysis was conducted to determine the existing conditions
and historical trends of the shorelines both east and west of
Shinnecock Inlet. Data used in this analysis consisted of
beach profiles along a total of 12 ranges covering a distance
of approximately 3,000 feet east of the inlet and 35,000 ft
to the west of the inlet. The 3,000 feet eastern limit was
chosen as the limit of beaches influenced by the east jetty.
Surveys of these range lines were conducted in 1955, 1962,
1974 and 1984. However, all of the ranges were not surveyed
in each of these years, thereby precluding analysis of the
different reaches for all survey periods. Aerial photographs
between 1953 and the present were used to supplement this
10 REVISED
survey data, providing visual records of the shoreline
movements throughout the history of the inlet. The quantity
of sand was estimated for each record of survey using the
average-end area method for computing volumes. Records of
dredge and fill projects were also examined to determine the
volume of material added to or removed from the project area
in the periods of interest.
C34. Shoreline Changes Adjacent To Shinnecock Inlet. The
information presented in this section consists of the
following: an accretion/erosion shoreline analysis for the
shorelines immediately east and west of the inlet, an
accretion/erosion analysis along the bay shoreline and a
review of the reported shoreline changes west of Shinnecock
Inlet to Moriches Inlet.
a. Ocean Shoreline East of Shinnecock Inlet. A
determination of the erosion/accretion changes on the ocean
side of the barrier beach adjacent to east jetty was made for
the periods following construction of the inlet in 1957. The
beach to the east of the inlet has shown accretion in all
periods examined. The results presented showed that the
shoreline advanced oceanward while volumetrically gaining
material. This accretion can be attributed to the trapping
effect of the east jetty. Based on the growth of the offshore
bar it is estimated that the east jetty has reached its
trapping capacity and sand is now naturally passing around
the tip of the jetty. It is concluded from the results of
this analysis and from observation of aerial photographs and
maps, that the ocean shoreline east of Shinnecock Inlet has
accreted to its fullest and is expected to remain at a
relatively stable configuration in the future.
Some erosion would occur along the beach face as a result of
extraordinary high tides or northeast storms, but it is
expected that this shoreline condition would quickly recover
with the onset of favorable spring and summer season
conditions. In the study area the littoral climate occurring
during spring and summer season is usually responsible for
the prograding or accretion of additional beach face area.
b. Ocean Shoreline Immediately West of Shinnecock Inlet
As previously stated for the east shoreline, an
erosion/accretion study of the shoreline was also
accomplished for the shoreline immediately west of Shinnecock
Inlet. The base survey (1955) was used for this analysis,
and a recent survey (June 1984) was used to provide
comparative coverage along with aerial photographs to
supplement these surveys. The results of the comparative
analysis indicates that the down-drift shoreline immediately
west of the inlet exhibits a markedly different behavior than
the shoreline east of the inlet. The shoreline west of the
inlet is characterized by alternate patterns of erosion and
11
accretion. The net effect however, has been a long-term
trend of erosion along approximately 6,000 feet of beach
immediately adjacent the west jetty (see Table C-6). The
beach area with the greatest erosion rate occurs within 3000
ft west of the Inlet. In the next 3000 ft westward a smaller
amount of erosion occurs along with an adjacent accretion
which balances the erosion. The erosion amounts to an
average of approximately 10 cubic yards per year per foot of
beach, or a total annual loss of approximately 61,000 cubic
yards for the first 3000 foot section, and coincidentally for
the entire 6000 ft section west of the inlet.
The western most range in this reach approximately 5000
ft. from the inlet, has exhibited accretion in the latest
periods of examination indicating that this is the point at
which natural by-passing is reaching the shore. (See Figure
C5 and Paragraph C34e) This is evident in recent photography
which shows a build-up of the beach at this location.
C. Ocean Shoreline Further West of Shinnecock Inlet.
An examination of the beaches further west of the inlet
was also conducted. These beaches also exhibit a long-term
trend of erosion, however, to much lesser degree. This
erosion is observed for a distance of approximately 30,000
ft. further to the west, after which accretion has occurred
in the eastern most compartments of the groin field along
West Hampton Beach. The long term erosion in this reach has
been calculated to be 2.3 cubic yards per year per foot of
shoreline, or a total annual loss of approximately 69,000
cubic yards per year.
Shoreline recession rates were also calculated for these
reaches, with an average recession of approximately 11.5
ft/year in the 6,000 ft. immediately west of the inlet and an
average recession of approximately 3.3 ft/yr in the total
distance of approximately 35,000 ft (7 miles). This
corresponds to a yearly loss of 2.7 acres of beach-front
property. These calculations are shown in Table C-6. It is
expected that these shoreline loss rates would be
representative of future without project conditions.
The existing condition long term erosion rates discussed
above are considerably less than the long term erosion rate
given in the Survey Report of 1957 (Reference 3, Table A2).
The average annual highwater recession was given as 10.8
feet/year for 72,700 feet of shoreline between Shinnecock and
Moriches Inlets (excluding approximately 5000 feet of
shoreline adjacent to each inlet). The decrease in the
erosion rates west of Shinnecock Inlet in the recent past is
confirmed by the comparison of shoreline compartments unit
volume changes for various time periods (1940-1955 and 1955-
1979) given in the Sediment Budget Study of 1983 (Reference
12).
12 REVISED
d. Bay Shoreline Erosion. The only bay shoreline which
is subject to erosion is the shore adjacent to the east
jetty. Based on an examination of aerial photographs and
existing slopes it is estimated that approximately 6,000
cubic yards are lost from this shore each year. This
sediment enters the inlet hydraulic system and may be.
deposited on the ebb delta/bar complex or continue as part of
the longshore transport.
e. Ocean Shoreline Change Map. Mean High Water lines
were extracted from aerial photos and compiled as a shoreline
change map. (See Figures C4 and C5) Though these shoreline
movements do not fully indicate volume changes occuring, the
visual evidence of shoreline motion supports volume analysis
results as described in Paragraphs C33 and C34a-c.
The reach 3000 ft. east of the jetty shows significant
movement of the shoreline oceanward in the period immediately
following construction. Examination of MHW lines for the
last twenty years shows some oscillation about a stable
configuration caused by occasional MHW erosion and subsequent
recovery.
Shoreline changes west of the jetty support the
erosion/accretion study results. Alternate patterns of
erosion and accretion are observed, with a net tendancy
towards erosion in the 3000 ft. immediately west of the
jetty. Proceeding further west, the oscillation of shoreline
in the next 3000 ft. is shown to be less extreme. This again
supports erosion/accretion study results. Long term erosion
rates west of the inlet are tabulated in Table C6.
C35. Development of Offshore Bar and Ebb Tide Delta:
Examination of the off-shore area in the vicinity of the
inlet indicates that two distinct phenomena are taking place.
These are the development of the ebb tide delta caused by
deposition of sediments transported by ebb tidal currents,
and the growth of an off-shore bar caused by sediments
naturally by-passing the east jetty. Although the separate
contributions of each of these processes is difficult to
estimate, the combined effect is a general rise in the ocean
bottom fronting the inlet. (See Figure C6) This rise was
calculated by comparing bathymetric surveys for the year
1955, 1984 and 1985. This comparison indicates that
approximately 100,000 cubic yards are deposited onto this
complex each year, with an average rise in the ocean bottom
of 0.5 ft/yr. in the vicinity of the existing thalweg and
across the offshore bar.
C36. Development of Flood Tide Delta: Examination of aerial
photographs has shown rapid development of the flood tide
delta after construction of the jetties in 1952-53. This
development slowed as the inlet stabilized. Current
13
REVISED
estimates are that 20,000 cubic yards are lost annually to
this delta. (See Figure C6)
C37. Sediment Budget: To provide better understanding of
the ongoing processes and long-term trends at the inlet and
adjacent shorelines and to estimate the magnitude of sediment
available to shoal within a deepened entrance channel, a
sediment budget for the inlet was developed. To create this
budget, all possible sediment sources and sinks were
investigated. These included deposition of drift on the
offshore bar, deposition in the bay on the flood-tide delta,
overwash losses to the bay, losses to the off-shore zone,
transport from bay and inlet erosion, and the erosion of
adjacent beaches. The effects of each of these budget
components is incorporated in the following discussion.
A sediment budget control volume was established using
the limits established by the survey range lines influenced
by the inlet and jetties; and the area of any improved
entrance channel. As shown in Figure C7 this volume extends
approximately 3000 ft. to the east of the inlet and 6000 ft.
to the west of the inlet. The -30 ft. MLW contour is used
as the offshore boundary. The extent of the flood tide delta
in the bay can be considered the northern boundary of the
volume. Long-shore transport rates for this control volume
were obtained from the sediment budget conducted for the
south shore of Long Island (1983) (Reference 12). This
report states that 300,000 cubic yards per year are entering
the control volume from the eastern boundary, with
approximately 247,000 cubic yards leaving the control volume
from the western boundary. It is to be noted that these
transport volumes are representatives of net sediment
movement only. Gross transport volumes, which represent
total sediment movement within the control volume, are
estimated to be 400,000 cy/yr. This gross rate includes the
drift from west to east into the deposition basin which can
be estimated from this sediment budget as 100,000 cy/yr. The
gross transport rate is used in the sedimentation analysis.
It is noted that the control volume boundaries were
established to estimate transport quantities which are
available for entrapment into a deepened entrance channel.
Using these transport volumes and the data discussed
above, a sediment budget for the inlet was formulated. This
budget, shown in figure C7, shows that a total of 367,000
cubit yards enters the control volume each year from beach
erosion sources and longshore transport, with 247,000 cubic
yards leaving the volume due to net longshore transport
across the western boundary. This leaves approximately
127,000 cubic yards distributed within the control volume of
this total, it is estimated that 20,000 cubic yards per year
are deposited on the bay shoal and 100,000 on the offshore
bar and ebb tidal delta complex. The 100,000 cubic yards
deposited annually offshore of the inlet will be available
14 REVISED
for rehandling in a dredged sedimentation basin and for
placement on the downdrift beaches.
It is noted that this sediment budget must be considered
preliminary, as the lateral growth of the offshore bar and
accretion rate of the ebb tide delta (0.5 ft/yr) was
estimated from a comparison of three surveys. (See Figure C6)
Examination of future monitoring surveys will give a better
indication of the rates of deposition and shoal movement on
this offshore complex during the next phase of studies.
STABILITY CONSIDERATIONS
C38. The stability of the inlet was estimated using the
inlet analytical hydraulic model for the existing inlet
configuration and subsequently for impacts of the proposed
dredging on the inlet hydraulics based on the principles
developed by Keulegan (reference 13). The model relates the
maximum flow velocity in an inlet to the minimum cross-
sectional area of the channel. Application of the model to
Shinnecock Inlet is contingent upon the assumptions listed
below. The results obtained are considered meaningful in
sofar as identifying possible inlet trends and not as a basis
for design.
a. the cross-sectional area is uniform over the length
of the inlet,
b. ocean tide can be represented by a sinusoidal
function
C. the bay water level rises and falls uniformly,
d. there is no substantial inflow to the bay other than
through the inlet,
e. the bay area is constant over all bay tide
ranges.
C39. A stability curve was developed which is representative
of conditions at the inlet. The peak of the curve, known as
the critical cross-sectional area, is interpreted to be the
point of incipient stability. For inlets with minimum cross-
section areas less than the critical area the flow is
governed by frictional forces. This results in an inlet
unstable to changes in flow area or maximum velocity. When
the flow area is reduced by shoaling or if the velocity is
reduced by changed flow characteristics, the inlet responds
by further reducing area or velocity until the inlet closes.
On a reduction the other hand, an unstable inlet which starts to scour by
will continue of sediment supply or an increase in velocity
to scour until the critical flow
the achieved. critical For inlets with cross-section areas area is
area, the flow through the inlet is greater governed than by
15
the continuity requirement resulting in an inlet stable to
changes in flow area or velocity. In this condition, any
change in cross-sectional area will cause the inlet to
respond by compensating in such a way as to force its return
toward the equilibrium position.
C40. A stability analysis, using surveys conducted in 1956
and 1984 shows that the inlet was unstable and in a scour
mode in 1956. However, the 1984 survey shows that the inlet
is now in a stable mode, with cross-sectional area greater
than the critical area. Figure C8 shows the basis of this
stability analysis in the form of a generalized hydraulic
stability curve. Figure C9 shows the stability curves
developed for Shinnecock Inlet for the 1956 and 1984
conditions. (See Computation C1 for details)
Once the stability of the inlet in its existing configuration
was established, it was necessary to determine the effects of
the proposed channel dredging on the inlet hydraulics. This
was accomplished through the use of the "Inlet 2" Numerical
model ( Reference 14). This model, through solution of
differential momentum and continuity equations, predicts
inlet velocities and discharges, and bay tide levels, for a
known tidal forcing function. Friction losses are determined
by establishment of a flow net for the inlet, with a
weighting function distributing flow at each cross-section SO
that friction is minimized. Using tide data obtained from
gages at the inlet and throughout the bay, bay tide stages
were successfully replicated indicating calibration of the
model to existing conditions.
Examination of the bathymetry (see plate 4 of the main
report) within the inlet reveals that there will be no
dredging between the jetties to provide the -10 ft. MLW
channel, as the existing bottom is much deeper. The most
landward channel dredging for this project will be for
construction of the deposition basin through the offshore
bar. Although at initial construction the dredging will
extend landward to the head section of the east jetty, the
dredge cut will be outside the inlet throat cross sections
that control the hydraulic flow characteristics and
similiarly outside the hydraulic flow net used for the
hydraulic modeling. For this reason, there would be no impact
on inlet and bay hydraulics caused by dredging through the
bar.
C41. Recent Maintenance Dredging at Shinnecock Inlet. In
April through May 1984, the Corps dredge "Currituck" was
brought to Shinnecock Inlet for an emergency dredging
operation. At that time approximately 160,000 C.Y. of
material was removed from various locations near the inlet
from dredge depths to -14 ft MLW and disposed to the west of
the inlet in the littoral system at depths of -10 MLW.
The dredging operation was for emergency purposes only and
16
was not performed to specific channel dimensions. The dredge
completed its operations by providing short term relief for
the commercial channel users.
PART II = PROJECT DESIGN
INTRODUCTION
C42. The purpose of this section is to provide the
engineering considerations and the design of the recommended
plan. Two major features of the plan are the jetty
rehabilitation and navigation channel with a deposition
basin. Paragraphs C45 to C62 pertain to the jetty
rehabilitation design, while paragraphs C63 to C89 are
devoted to the navigation channel and deposition basin.
Basis of Design
C43. The design of coastal protective works constructed by
Federal and non-Federal interests before development of the
existing design criteria provided in general a level of
protection commensurate within the given economic guidelines
and rational engineering practices.
C44. Both the Corps design criteria and the as built design
level of protection have been considered for the basis of the
design of the proposed project improvements.
C45. Design Criteria. The design for the rehabilitation
of the rubble-mound jetties and the repair of the revetments
is in accordance with the provisions of the following
memorandums and manuals:
2. EM 1110-2-2904, dated 30 April 1963, Design of
Breakwaters and Jetties (Reference 15).
b. EM 1110-2-1607, dated 2 August 1965, Tidal
Hydraulics (Reference 16).
C. Shore Protection Manual, Volumes 1, and 2, dated
1984, fourth edition, CERC (Reference 17).
d. ETL 1110-2-305, dated 16 November 1984, Determining
Sheltered Water Wave Characteristics (Reference 18).
e. EM 1110-2-1614, dated 30 April 1985, Design of
Coastal Revetments, Seawalls and Bulkheads.
(Reference 19).
f. ER 1110-2-1457, dated 24 June 1985, Hydraulic Design
of Small Boat Navigation Projects (Reference 20).
9. EM 1110-2-1615, Hydraulic Design of Small Boat
Harbors (Reference 21)
17
C46. Description of Proposed Structural Work. The proposed
structural work includes the following major items:
rehabilitation of the west and east jetties head sections
including scour blankets, repair of isolated sections of the
east jetty, replacement of north east revetment and
construction of bay revetment behind the east jetty. The
engineering considerations requisite to design and a brief
description of the repair (s) work are summarily presented in
the Project Design Section of this appendix and discussed in
detail in the structural appendix with a summary of work
given in Table B3 of the Cost Appendix, which is based on
Plate No. 3.
C47. Pertinent Data on Existing Structures.
(a) East jetty
(1) Originally constructed to a length of about
1360 ft. in 1953 by the State of New York;.
(2) Crest width 12 feet;
(3) Crest elevation +7.8 N.G.V.D. (+9 mlw);
(4) Jetty Trunk - Side slopes one vertical on
three-halves horizontal;
(5) Original stone units in head portion 6 to 12
tons.
(6) Stone revetment 700 ft long constructed in
1953 -2 to 4 ton stone.
(b) West jetty
(1) Originally constructed to a length of about
850 feet in 1953 by the State of New York;
(2) West jetty extended to a total length of 950
feet in 1954;
(3) Crest width 12 feet;
(4) Crest elevation +7.8 N.G.V.D. (+9 mlw);
(5) Jetty trunk - side slopes one vertical on
three-halves horizontal;
(6) Original stone units in head portion 6 to 12
tons;
(7) Pile Crib revetment was constructed in 1959 at
the north end of the west side of the inlet
and replaced by armorstone revetment in 1982.
18
(c) Maximum breaking wave resisted by existing west
jetty head section
(1) The existing jetty consists of one layers of
cover stone placed on a stone core. A breaking wave
that will require a 12 ton stone and slope of 1 on 1.5
is about a 11.8 ft. wave. Therefore, it is probable
that the existing west jetty head section is capable of
resisting up to a 11.8 ft. wave without significant
damage. (See Computation C2 for details.)
(d) West and east jetty head sections - There has been
a considerable loss of armor stones at the seaward end of
both the east and west jetties. Comparison of hydrographic
surveys of the inlet from 1955 through 1984 reveal that 50
ft. of the seaward end of the west jetty and 50 ft. of
seaward end of the east jetty armor layer units have
undergone severe displacement and between 150 ft. and 200 ft.
of adjacent sections have undergone significant movement.
The failure was probably caused by the undermining of the
structure toe by the scouring action of the ebb currents
since significant scour holes exist at both head sections.
Another factor in the failure may have been the existence of
only one layer of capstone at the head section and not the
two layers recommended by Corps criteria. The stone for the
head sections will not have to be any larger as waves higher
than 12 ft. have occurred since construction of the jetties
and the sections did not suffer significant loss of
stability.
(e) Isolated east jetty sections in need of repair (see
Appendix D for details)
(1) Along intermittent sections of the east jetty
there has been partial washout of the jetty stones,
crest settlement and loss of interlocking of the cap
stones, for a total length along the jetty of
approximately 700 ft.
(2) Two areas at the northern end of the jetty are
completely deteriorated. Wave action in the inlet has
eroded the sand on the beach side of the jetty at these
washouts; continued loss of sand would further undermine
the existing jetty.
(f) Bay Side Revetment - The original revetment north-
east of the east jetty has completely washed away and the
shoreline is receding. To control the erosion on the bay
side of the inlet a blanket of stone will be placed along
the bayside shoreline for a length of 1000 ft. to the east of
the east jetty. The stone revetment is designed to stabilize
19
the bay shoreline affected by ebb-tidal current erosive
forces and thereby reducing maintenance costs for the sand
replenishment.
STRUCTURAL DESIGN
C48. General. The repairs required were determined based
upon the findings of structural field surveys, and site
inspections and are a feature of all the alternative plans
considered.
C49. Rehabilitation of the West Jetty. The improvements
will provide for stabilization of the ocean bottom fronting
the jetty head section, and reconstruction of the seaward 200
feet of jetty head section
C50. The ocean bottom fronting the structure will be
stabilized by placement of a stone blanket within scour hole
to an elevation of -30 ft. mlw. A design current velocity
was used to select the bottom stone size.
C51. The maximum velocity of tidal current through inlets
opening as stated in Chapter 7, Section IV. SPM, Pg. 7-250 is
a function of surface bay area, channel cross-sectional area,
period of tide, and range of bay tide. A maximum current
velocity of 10 ft./sec is estimated using equation 7-128,
SPM, Pg. 7-250. See computation sheet C3 for sample
calculations.
C52. Selection of the armor stone size for the west jetty
rehabilitation is a function of the design wave height,
structure slope, unit stone weight, and stability
coefficient. The existing head section armor stone sizes are
considered stable for a breaking wave height of about 12 ft.
C53. The results of an existing condition design wave
analysis (see computation sheet C4) indicates that the wave
height is limited by the stillwater elevation above the
offshore shoal fronting the inlet. The computations
indicates that a 15.6 ft. breaking wave allows for maximum
wave impact when the jetty is subjected to submersion by a
storm surge. This surge of +12 MLW has an associated return
period of about 70 years (see refer. 27). For the with
project conditions (with deposition basin and channel
improvement in place) the computations indicate that a 21 ft.
breaking wave allows for maximum wave impact. However from
review of the WIS wave climatology and a simplified
refraction analysis the maximum expected breaking wave height
is 16 ft. The estimated damage rate for the 12 ton armor
units subjected to the expected 16 ft. breaking wave would
be 25 percent (see calculation sheet-Appendix D).
20
C54. Proposed Revetment Along Bay Shoreline - To stabilize
the bayside of the dune and prevent material losses estimated
at up to 6,000 CU. yds. annually, a revetment was designed
using Corps criteria.
C55. As previously discussed in paragraph C34d, the
redistribution of the tidal currents resulted in shoreline
recession and steepening of the adjacent bayshore contours.
In order to evaluate the proposed revetment an analysis of
the wave and current erosive forces was undertaken. The
maximum probable current velocity estimated along the
proposed revetment (see computation sheet C3) would be about
7 ft./sec although the measured average daily maximum
velocities were reported (reference 22) to range from 2 to 4
ft./sec.
Although the shoreline in the vicinity of the proposed
revetment is sheltered from the ocean waves it is
not sheltered from waves generated within the bay and/or
produced by passing boat traffic. Using the procedures
published in the Shore Protection Manual (reference 17), and
ETL 1110-2-305 (reference 18) for generation of shallow water
waves, a maximum 3.3 ft breaking wave was computed. (See
Computation Sheet C5.)
C56. The revetment would extend from the existing channel
bottom (el. -5 ft. mlw) to insure adequate toe stability,
thence follow a 1 on 5 slope to elevation +7.7 NGVD. The top
of this proposed revetment would tie into the top of the
existing east jetty. ( See Structural Appendix for further
design details)
C57. Repair of East/West Jetty and Jetty Revetment - The
jetties are in appreciably damaged condition in some
sections; some rehabilitation has been applied to the
structures since their construction in 1953/1954. For a
detailed discussion on existing jetty condition see paragraph
D4 of the structural Appendix D. Based on. several field
investigations, aerial photographs, and topographic study of
the immediate vicinity of the jetty areas, the jetties have
been effective in blocking sand movement through their
interstices. Damage has been limited to isolated sections of
the structures and does not warrant a complete redesign,
however, the head section of both jetties will have two
layers of armorstone. Although littoral materials appear to
bypass around the seaward ends of the jetties along the ebb
shoal fronting the inlet the jetties are structurally tight
and continue to provide an effective barrier to sand movement
through the interstices and into the existing channel. As
part of the proposed monitoring program, quarterly site
visits will be accomplished and include a visual inspection
of both jetties and the results presented in annual reports.
However, the structures do not meet Corps' criteria for layer
thickness, stone weights, or crest height (reference 2). To
21
rehabilitate the structures to Corps' criteria would be very
costly and in light of the structures past structural
performance would not be justified. Therefore, it has been
determined that repairing the structures to their "design
dimensions" would be the basis for design.
C58. Repair of the east jetty would consist of the
replacement of 420 ft. of the jetty where there has been
complete washout of the stones. In other sections of the
jetty which have experienced sloughing and settlement of
stones (approximately 700 ft.) the original stones will be
removed and reset to insure interlocking. The 250 ft. head
section of the jetty will have to be totally repaired with
some original stones and some new stones. A scour blanket
will be placed at the head section for stability of the toe
of the structure.
C59. Construction of the 1000 ft. bay revetment will consist
of filter cloth and graded riprap.
C60. The oceanward 200 ft. section of the west jetty will be
repaired similarly to the head section of the east jetty.
New capstone and core stone will be needed to supplement the
displaced stones of the existing jetty. A scour blanket will
be placed at the head section of this jetty also.
CHANNEL DESIGN
C61. General. The purpose of this section is to present the
engineering considerations necessary for design of the
navigational elements of the plan considered. These elements
are summarized in Tables 1 and 2 of the Cost Appendix and
provide for a navigation channel, a sand deposition basin,
and periodic maintenance dredging.
C62. Design Criteria. The design of the navigation channel,
sand deposition basin and periodic maintenance dredging was
based upon the provisions of the following memorandums and
manuals:
a. EM 1110-2-1615, Hydraulic Design of Small Boat
Harbors (Reference 21).
b. ER 110-2-1457, Hydraulic Design of Small Boat
Navigation Projects (Reference 20).
C. ETL 1110-2-293, Entrance Channel Infill Rates
(Reference 24).
d. Special Report No. 2, Small Craft Harbors:
Design, Contruction, and Operation, (Reference 25).
22
C63. Existing Navigation Conditions Fronting the Inlet. The
waters fronting the inlet are characterized by crossing wave
crest patterns. The complicated surface patterns are caused
by refraction of ocean water waves at the inlet mouth with
shallow water conditions over the inlet's shoals. Breaking
waves due to these shallow water conditions and unpredictable
inlet conditions resulting from the interaction of wave and
tidal currents present additional navigation concerns.
C64. The inlet shoal typical of most sandy coast inlets is
located just offshore of the inlet due south of the east
jetty. As a result of increased shoaling, sections of the
offshore outer bar are now at -8 ft. MLW. The presence of
this shoal forces all channel users to take a southwestern
course through the naturally deep area west of the shoal in
the majority of sea conditions. The shoal is migrating to the
west across the inlet infringing on the deep channel causing
an unstable condition of the channel including apparent width
fluctuations. Mariners navigating this channel take
advantage of greater depths but expose their vessels to
broaching ocean waves while steering to and from the inlet.
C65. Vessel Types and Sizes. Currently commercial fishing
vessels, charterboats and private recreational boats use
Shinnecock. A total of 48 commercial fishing vessels utilize
the inlet with lenths varying from 40 to over 80 feet, beams
varying form 12 to 23 ft, and drafts from 5 to 10.5 feet.
For commercial fishing vessels the design dimensions of the
90th percentile vessel to be used in the channel design are
as follows: 80 ft length, 22 ft beam and 10 foot draft.
Approximately 700 recreational vessels use the inlet
regularly. The design dimensions for the recreational
vessels are as follows: 60 ft. length, 15 ft. beam, and 4
foot draft.
C66. Methodology of Channel Design = Design Requirements.
With respect to channel dimensions, vessel safety and
maneuverability are the paramount design criteria. As
described above, navigation through the inlet entrance is a
difficult and hazardous task that should only be undertaken
by experienced sailors. The minimum width of channels
necessary to provide for safe maneuvering lanes for the two-
way traffic of small craft and fishing vessels in inlets has
been developed in EM 1110-2-1615, Hydraulic Design of Small
Boat Harbors (Reference 21). The width of a maneuvering lane
varies with the relative maneuverability, of the design
vessels. Both the commercial and recreational vessels can be
considered to have very good maneuverability. therefore the
minimum recommended maneuvering lane width was determined to
be adequate for the design vessels. The dimensions of bank
clearance and ship clearance lanes depend not only on the
maneuverability of the design vessels, but also on the
effects of the vessel motion on other vessels and adjacent
23
shorelines. Modifications to the design criteria were based
on the maneuverability of the design vessel, on examination
of site specific conditions such as wind, wave and current
data, and communication, and recommendations of professional
mariners in the area. A prudent application of engineering
judgement resulted in the design of a safe and adequate
navigation channel for the design vessels utilizing two-way
traffic.
C67. Description of Parameters -- Channel Width. Using the
design vessels as described in Paragraph C65 the minimum
allowable width two-way channel was designed to accomodate
the fleet which uses Shinnecock Inlet. As described in
Computation C6, the width of the navigation channel was
calculated. For vessels with very good maneuverability, the
dimensions as a percent of the vessel beam are as follows:
maneuvering lane = 160%, ship clearance lane = 80% of larger
vessels. The bank clearance percentage was increased to 150%
of the vessel beam due to the existence to the rubble mound
jetties and the adverse weather and hydraulic conditions at
the inlet. An additional 70 ft. of channel width is
necessary to provide sufficient allowances for the outriggers
used at all times by the commercial fishing vessels while
transiting the inlet channel. The required design channel
width of 200 ft. has been presented to the Coast Guard and
the channel users for concurrence. Channel widths larger
than 200 feet are not required for the vessel fleet at
Shinnecock Inlet. The authorized bay channel is 6 ft. deep
MLW and 100 ft wide from Shinnecock Inlet to the Long Island
Intracoastal Waterway and is adequate for the recreational
vessels which are the primary users of the bay channel.
C68. Channel Depth. The channel depth was determined by
economic analysis utilizing EC 1105-2-118 (NED Benefit
Evaluation Procedures: Deep Draft Navigation Analysis and
Design Underkeel Clearance Standards) and ER 1105-2-40
(Planning & Guidance for Navigation) which emphasizes the use
of actual operating practices to determine most likely with
and without project conditions over the project life,
including the use of tides and light loading. The actual
operating conditions were obtained from the users of the
channel. Channel depths of -8, -10 and -12 feet MLW were
considered. The -8 Ft. MLW channel is the same depth as the
offshore sandbar which is not presently used by the vessels.
The vessels have a choice to go over the -8 foot MLW sandbar
or put their boat at a skewed angle to the waves and head for
the natural channel. The vessels avoid the sandbar and
choose to use the deeper natural channel even though it is on
a skewed angle. The -10 ft. and -12 ft. MLW channel depths
were evaluated in following paragraphs and Appendix B.
C69. Channel Alignment. An ocean entrance channel alignment
parallel to the existing jetties and extending offshore on a
compass direction of 176 degrees true north was investigated
24 REVISED
with a variety of considerations including safety,
maneuverability, initial dredging, and maintenance
requirements, in order to corroborate the previous study
finding (ref.3). First, an investigation of the wave climate
and bathymetry fronting the inlet was conducted to evaluate
the location for the proposed channel and the predominant
direction of wave approach. Based on this investigation and
Table C4 from the Waterways Experiment Station W.I.S study
(ref. 10 ) it can be demonstrated that the predominant
direction of wave approach is a 30 degree sector between
compass azimuths 159 and 189 degrees. The recommended
channel alignment which is on an azimuth of 176 degrees is
well within this predominant wave group and runs straight
through the inlet and parallel to the existing jetties and
continuing oceanward over the sand bar fronting the inlet for
a distance of approximately 2000 ft. This orientation would
provide the only safe angle of approach out of the inlet,
aligned perpendicular to the predominant direction of wave
approach, thereby, reducing the incidence of broaching waves.
Removal of the the offshore bar will reduce the height of
breaking waves providing safer access into the inlet. The
channel alignment was not varied since the straight channel
is the only safe angle of approach and therefore the only
channel alignment possible. Figure C10 shows the recommended
channel alignment.
C70. Since unconstrained available bay area channel
approaches would be available to mariners between the ocean
entrance channel and the Intercoastal Waterway the minimum
practicable bay channel is recommended. The dimensions of
the inner channel, 6 feet deep mlw by 100 feet wide, are the
minimum practicable and conform with the dimensions of the
existing project for the Long Island Intracoastal Waterway
with which they connect.
C71. The channel has been located in the deepest suitable
areas in the inlet and bay to minimize the required initial
dredging and future maintenance, while remaining consistent
with safety of navigation under present hydrographic
conditions.
C72. Deposition Basin. The channel design section can be
viewed as consisting of two basic elements; the channel
cross-sectional area required to carry vessel traffic,
referred to as the project dimensions, and below it and to
the sides a basin cross sectional area which is utilized for
the storage, between maintenance operations, of littoral
materials brought within the channel boundaries by tide and
wave current action. This advance maintenance over depth
zone will be referred to as the deposition basin.
25
REVISED
C73. For the recommended channel alignment of 176 degree,
the deposition basin design would provide for a dredged cut
roughly trapezoidal in shape. For each combination basin
bottom width and elevation of cut the basin bottom will slope
upward (one vertical to five horizontal) to the existing
bottom. The basin would encompass the channel through the
offshore bar from the seaward end of the jetty extending
oceanward about 2600 ft.
C74. Dredge Disposal Sites. All the alternative deposition
basin plans require placement of the material obtained from
dredging the project channels and deposition basin in a
dedicated disposal area. The disposal area considered is as
follows.
Ocean Shoreline West of Shinnecock Inlet. The
excavated suitable material will be placed in various
shoreline areas to a distance of approximately 5000 ft due
west from the west jetty. For a distance of 3000 ft from the
west jetty disposal sand will be placed on the existing beach
face from elevation +10 MLW to approximately -10 ft. MLW.
Downdrift of this section, 5000 ft from the west jetty and
westward, disposal material will be placed in the littoral
zone to -20 ft. MLW. These disposal areas have been located
50 as to place the dredged material that has been trapped at
the inlet shoal back along its original path to the west,
thus keeping it within the littoral regime, and available to
nourish adjacent shores.
C75. Periodic Maintenance = - Bay Channel. The authorized
project also includes a bay channel, 6 feet deep (MLW) and
100 ft. wide, connecting the inlet with the Long Island
Intracoastal Waterway in the vicinity of the Ponquogue
Bridge. A hydrographic survey of the bay area shows depths
from -15 to -20 feet MLW throughout the proposed channel
area, allowing for the establishment of this channel, through
the alignment authorized, with no initial construction
dredging or periodic maintenance anticipated.
C76. Periodic Maintenance = Inlet Channel. The 1700 ft.
section of entrance channel which is aligned between the
existing jetties will not require the cutting of the existing
natural channel bottom. Since the existing cross sectional
areas naturally occurring between the jetties provide
adequate depth and width for up to 450 ft. channel it is
expected that no channel maintenance would be required for
these channels. As previously discussed in para. C39, the
inlet appears to be approaching an incipient stability point
by naturally increasing its minimum cross sectional area;
therefore, it is expected than any increase in area would
probably maintain itself.
26
C77. Periodic Maintenance = Ocean Entrance Channel. The
maintenance of the inlet entrance channel cross-sectional
flow area is related to its hydraulic and sedimentation
characteristics. Reliable estimates can be made where
dredging records are available for inlets that are maintained
and have similar sediment transport, textural and hydraulic
characteristics.
C78. Of the six sandy coast inlets on the south shore of
Long Island, only Moriches Inlet is similar in hydraulic and
sedimentary characteristics. Since the ocean entrance is not
maintained, there are no records available for estimating
channel entrance shoaling rates.
C79. The method chosen to estimate the deposition changes
that may occur and to estimate the probable maintenance
requirements for the proposed channel dimensions in this
study is the transport ratio method, also known as the
Moriches Inlet Method (Reference 23 and 24). Application of
this method requires an estimate of gross longshore littoral
transport volume moving past the dredged channel each year,
and the distribution of this sediment transport with depth.
These quantities are required to determine the amount of
sediment available to be trapped by basins dredged to various
alternative depths. Based on the results of a sedimenti
budget study and an examination of the wave climatology, a
value of 400,000 cubic yards per year was determined for the
gross transport at Shinnecock, available for entrapment into
the channel cut.
The Shoaling Factor Method (see the Moriches Inlet GDM,
Reference 23) was also used to evaluate the shoaling within
the proposed deposition basin at Shinnecock Inlet. The
results of these analyses predicted longer infill times than
the Moriches Inlet (Transport Ratio) Method for more shallow
dredge depths (-14, -17 ft. MLW). For the project design
dredge depth of -20 ft MLW there was good agreement between
the two methods, however the transport Ratio Method continued
to provide more conservative estimates of maintenance
dredging cycles which were utilized in the project design.
The comparative surveys approach (Simplified Shoaling Rate)
was not conducted due to the lack of sufficient survey data.
Only three hydrographic surveys are available. The Lamble
Method can not be utilized to study the Shinnecock Inlet
deposition basin due to the flow characteristics at the basin
which due to the longshore current are not normal to the
channel. (More information on these modeling methods can be
found in Reference 24).
C80. Application: To determine the optimum sedimentation
basin design, a matrix of alternative basin dimensions was
developed. The parameters that may be varied in the
development of these alternatives include: basin width,
27 REVISED
channel design depth and dredging depth. Basin lengths and
existing natural depths are a function of channel alignment
in that these values are determined by the dimensions of the
off-shore bar where it is cut by the channel. For the
recommended channel alignment, basins varying in width and
depth were developed for analysis. Larger basins provide a
greater trapping capacity at large initial cost, while the
reverse is true for the smaller basins. Selection of the
optimum is based on the results of an economic analysis. The
matrix of basin alternatives was developed by varying the
basin dimensions within these ranges.
Basin Widths:
Varying from 500 to 800 ft.
Channel Design Depth:
10 and 12 ft.
Basin Dredge Depth:
17 to 22 ft.
For all of the basin alternatives developed, a basin side
slope value of 1 ft. vertical in 5 ft. horizontal was used.
This slope was found to be stable in previous dredging
projects at Long Island Inlets.
C81. Due to the large number of sedimentation basin
alternatives, an analysis was conducted using a computer
application of the transport ratio method. (See Computation
Sheet C7 for sample calculations.) Use of this model
requires that the dredged channel and basin cuts be
represented as idealized trapezoidal sections. These
sections were developed by examining the bathymetry in the
area of the recommended alignment, and by spatially
integrating, producing a representative cross-section through
the off-shore bar. For the recommended channel, a section
with a crest natural depth of -8.0 MLW and a crest length of
600 ft. was established. Slopes of 1 ft. vertical in 70 ft.
horizontal were established for this section, as shown in
Figure C10.
C82. Results: Results of this analysis as detailed in the
Cost Appendix indicates that the most cost effective straight
channel alternative will call for a channel design depth of -
10 ft MLW and the maintenance of a basin approximately 800
ft. in width at -20 ft MLW. The results of the volumetric
shoaling analysis are given in Table C7 for the various
sedimentation basin alternatives. Dredging volumes are based
on shoaling rates and are quantified in Table 4 of the Cost
Appendix.
C83. Effects of Channel Design On Existing Inlet/Bay System.
The tidal prism in Shinnecock Bay due to construction of the
proposed navigation project should not change significantly.
The tidal prism is dependent on the cross-sectional geometry
of the inlet, specifically the minimum cross-sectional area
and because no change in the historic minimum cross-sectional
28
area range of the inlet is expected to occur as a result of
these plans, there should be no changes in the tidal prism.
Accordingly, since normal tidal flooding is a function of the
tidal prism, which is, in turn, a function of inlet throat
cross-sectional area which is not expected to change, there
should be no increase in normal tidal flooding of lowlying
areas resulting from project implementation.
C84. The proposed work should not have any measurable impact
on the tidal hydraulics of Moriches Bay. The hydraulics of
Moriches Bay are predominantly related to the capacity of
Moriches Inlet as the hydraulics of Shinnecock Bay are to the
capacity of Shinnecock Inlet. However, the canals which
connect Shinnecock Bay to the other bays are small and the
quantity of water that may be conveyed is correspondingly
small, when the conveyance of the canal is compared to the
tidal prism of either bay. The proposed work should have no
measurable effect on Shinnecock Bay. Therefore, there can be
no effect on Moriches Bay.
C85. The proposed channel alignment and sedimentation basin
will not impact the sediment budget in terms of net littoral
movement to the west.
PART III - PROJECT MONITORING PROGRAM
C86. General. In order to estimate future channel
maintenance requirements, and also document the results of
the improvements, it is proposed to monitor the project for 6
years after construction. The monitoring survey will cover
the inlet and ocean shores up to 10 miles east and west of
the inlet. In addition to replicating past survey coverage,
detailed coverage be obtained to monitor the proposed
offshore disposal site and vicinity. The monitoring program
is divided into four tasks as follows.
C87. Task I = Fill Placement. The beach fill will be
monitored at selected intervals before and after initial fill
placement and subsequent 1.5 year maintenance dredging fill
placement along 15 profiles as scheduled in Table C8 and
shown in Figure C11. The 15 profiles consist of 11 sites
west of the inlet within the fill area (includes two control
profiles, two and three miles west of the project limits). A
higher density of profiles will be around the proposed
nearshore fill area. Four profile sites will be east of the
inlet. Specifically, the profile transect spacing is:
29 REVISED
- Transect 1 - 4 1000 ft apart
- Transect 4 - 8 500 ft apart
- Transect B - 9 1000 ft apart
- Transect 10 & 11 are 2 and 3 miles west of inlet
- Transect 12 - 14 1000 ft apart
- Transect 15 is 1 mile east of inlet
Sediment samples will be collected during each profile
survey, at three sample locations (Mean High Water - MHW,
Mid-Tide level - MTL and Mean Low Water : MLW) per profile
line. A total of 30 short cores will be collected (3
sampling locations on 10 selected profile lines) on the pre-
fill placement sampling trip to characterize variability in
native beach seasonal and storm related sediment
distribution.
C88. A monitoring team will survey the 15 profiles once
yearly, collecting both onshore and offshore data to identify
the seaward depth of profile closure and to characterize the
active envelope of fill response. Sediment redistribution
across the entire profile will be monitored during this
survey by collecting seven surface sediment grab samples
(MHW, MTL, MLW, bar trough, offshore bar crest, offshore bar
seaward slope, and at closure depth) with the assistance of a
geologist. Profile lines 4 through 6 will monitor the
nearshore fill placement area, with seven sediment samples
collected during all profile sampling periods at MHW, MTL,
MLW, bar trough, offshore bar crest, crest of fill placement
mound, and at closure depth.
Beach Fill Area Sediment Sampling Scheme:
YEAR
TIMES/YR
NUMBER OF SAMPLES
TOTALS
Pre-
1
30 cores (3 cores X 10 profiles) +
75 surface (4 samples offshore at the
10 profiles and 7 samples X 5 profiles)
105
Post- 1
7 surface X 15 profiles
105
1
4
3 X 3 surface X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
2
4
3 X 3 surface, X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
3
4
3 X 3 surface X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
30 REVISED
Beach Fill Area Sediment Sampling Scheme (Cont.)
YEAR TIMES/YR
NUMBER OF SAMPLES
TOTALS
4
4
3 X 3 surface X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
5
4
3 X 3 surface X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
6
4
3 X 3 surface X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
7
1
3 X 3 surface X 15 profiles +
4 surface offshore X 4 profiles +
1 X 7 surface X 15 profiles
256
Monitoring fill after major storm events (greater than 20
year return) would include sediment sampling at 3 surface X
15 profiles = 45 samples/storm event, and would be performed
as an add-on cost to the scope of work.
C89. Data Analysis will include: profile volume change and
shape readjustment, area of loss or gain on profile, volume
of fill remaining on project, assessment of alongshore and
cross shore fill movement from beach and nearshore fill
placement area, and seasonal and storm response. Sediment
analysis will include grain size statistics of native and
fill material, with readjustment over monitoring period,
seasonal and storm grain size response, and assessment of
fill and renourishment factors to future fill requirements.
Report writing will summarize behavior and response of beach
fill to local and regional coastal and geomorphic processes.
C90. Task II - Borrow Area. Borrow area monitoring will
include collection of cores before dredging and surface
samples immediately after dredging to support biological
monitoring and assessment of fill suitability. These tasks
will be coordinated with a biologist for concurrent
collection period. Table C8 also includes a summary of the
borrow area sampling. During the seventh (last) year of
monitoring, the monitoring team will collect 5 cores in the
dredged area of the depositional basin. Sampling will
include one control site outside of immediate borrow pit.
About 6 samples will be taken per core (20 ft. long) for a
total of 36 samples. This sampling will also be coordinated
with biological sampling of the borrow area.
C91. Data analysis will include sediment statistics in
tabular and graphic form for sediment fill suitability,
borrow area sedimentology to support biological analysis and
31 REVISED
usability of borrow area for future projects, and analysis of
subcontractors bathymetric surveys for changes in borrow pits
and calculation of infilling rates. Report writing will
evaluate borrow changes, determine the rate of borrow area
infilling, and identify current patterns in the immediate
area of the channel and basin.
C92. Task III = Shoreline Change. A subcontractor will
provide 15 rectified aerial photography overflights of the
project area and construct a base map. Coverage will be a
single flightline with 60% overlap stereo coverage of entire
project area shoreline, including control profile locations
one mile north and south of project limits. Black and White
or Color Infrared film with a 9x9 inch film format will be
specified. The scale of the photographs will be sufficient
to identify shoreline features. A scale of 1:500 is
suggested for the base map and aerial photography. Proposed
aerial flight times are listed on Table C8 and should be
coordinated to occur during ground surveys.
C93. Data analysis done will include shoreline changes and
profile changes from pre- and immediately post-construction,
and bi-annually as in Table C8 to cover post maintenance
dredging. Products provided will be tables and maps on
shoreline change rates and volume calculations of fill
remaining at each flight time. Report will augment the
acquired data base of historic shoreline and inlet shoaling
to determine the readjusted rates of accretion and erosion
along the shoreline and changes to the ebb shoal/dredged
basin area. This is important to assess inlet shoal and
beach fill changes.
C94. Task IV = Biological Assessment. Biological surveys of
both beach and borrow areas will be conducted. One biologist
and technician will join the field team for the proposed
field trips listed in Task I and II. Field collection will
consist of grab samples offshore and quadrate of beach areas
to assess presence of infauna.
C95. Data Analysis will evaluate changes in infauna located
in the beach fill and nearshore fill deposition area, effects
of turbidity on fauna of the beach and borrow area and the
effects of dredging activities on borrow area infauna.
Report will describe and quantify the changes to or the
reestablishment of the biological community in the fill
placement area and borrow and compare to control sites.
32 REVISED
References
1. U.S. Department of Commerce, National Oceanic &
Atmospheric Administration, Nation Ocean Survey, "Tide
Tables 1985, East Coast of North and South America
Including Greenland."
2. Dewal, A.E., - Beach Changes at Westhampton Beach, New
York, 1962-73, U.S. Army Corps of Engineers, CERC, Misc.
Report No. 79-5, August 1979.
3. U.S. Army Corps of Engineers, New York District
Moriches and Shinnecock Inlets, Long Island, New York,
September 1957, Revised 11 July 1958, Survey Report.
4. Tetra Tech "Circulation Calculations in Shinnecock Inlet
and Vicinity" January 12, 1981.
5. U.S. Department of Commerce, National Oceanic &
Atmospheric Administration, National Ocean Survey "Tide
Current Tables 1985, Atlantic Coast of North America."
6. U.S. Naval Weather Service Command, Summary of Synoptic
Meteorological Observations, North American Coastal
Marine Areas, Vol. 2.
7. Helle, J.R., - Surf Statistics For the Coasts of The
United States, Beach Erosion Board, Technical Memorandum
108, November 1958.
8. Neuman, G. and James - North Atlantic Coast wave
Statistics Hindcast by Wave Spectrum Method, Beach
Erosion Board Technical Memorandum No. 57.
9. PRC Harris, Inc., Moriches Inlet, New York
Current and Tide Observations, Contract DACW51-79-C-
0005.
10. U.S. Army Engineers Waterways Experiment Station WIS
Report 9, Atlantic Coast Hindcast, Shallow Water
Significant Wave Information, January 1983
11. Taney, N.E., Geomorphology of the South Shore of Long
Island, New York; Beach Erosion Board, Technical
Memorandum No. 128, September 1961.
12. Research Planning Institute, Inc. Sediment Budget
Analysis, Fire Island Inlet to Montauk Point, Long
Island, New York -Reformulation Study, Revised December
1983.
13. Keulegan, G.H., Tidal Flow in Entrances Water Level
Fluctuations of Basins in communication with SEAS, Corps
of Engineers, U.S. Army June 1967.
14. U.S. Army Engineers "A Simple Computer Model for
Evaluating Coastal Inlet Hydraulics" CETA 77-1.
15. U.S. Army Engineers "Design of Breakwaters and Jetties",
EM 1110-2-2904, 30 April 1963.
16. U.S. Army Engineers "Tidal Hydraulics", EM 1110-2-1607, 2
August 1965.
17. U.S. Army Engineers Coastal Engineering Research Center,
"Shore Protection Manual", 1984.
18. U.S. Army Engineers "Determining Sheltered Water Wave
Characteristics." ETL 1110-2-305, 16 February 1984.
19. U.S. Army Engineers "Design of Coastal Revetments,
Seawalls and Bulkheads" EM 110-2-1614, 30 April 1985.
20. U.S. Army Engineers "Hydraulic Design of Small Boat
Navigation Projects" ER 1110-2-1457, 24 June 1985.
21. U.S. Army Engineers "Hydraulic Design of Small Boat
Harbors" EM 1110-2-1615.
22. House Document No. 126, 86th Congress, 1st Session,
Moriches and Shinnecock Inlets, Long Island, New York.
23. U.S. Army Engineers, New York District, General Design
Memorandum, Moriches Inlet, Long Island, New York, April
1983.
24. U.S. Army Engineers "Entrance Channel Infill Rates",
ETL 1110-2-293, 15 March 1984.
25. U.S. Army Engineers Coastal Engineering Research Center,
Small Craft Harbors: Design, Contruction, and operation"
Special Report No. 2, December 1974.
26. U.S. Army Engineers Coastal Engineering Research Center,
Simplified Method for Estimating Refraction and Shoaling
Effects on Ocean Waves, TM-59, November 1975
27. U.S. Army Corps of Engineers, Atlantic Coastal of Long
Island, N.Y., Fire Island Inlet to Montauk Point.
Cooperative Beach Erosion Control and Interim Hurricane
Study (Survey) -Appendices and Main Report, July 1952.
TABLE C = 1
SHINNECOCK INLET AND BAY TIDE RECORDS
Elevation
Mean
(ft. NGVD)
Mean
Range
Period of
Location
Mean High
Low
of tide
Record
of gage
Water
Water
(ft.)
(mo.)
Remark
East Quogue
0.64
-0.06
0.70
3 1/2 (1949)
0.49
0.00
0.49
2 1/2 (1951)
0.65
0.23
0.88
12
(1956)
Ponquogue
0.08
-0.02
0.10
1/2 (1938)
Prior to opening
Bridge
of Shinnecock
Inlet
0.93
0.07
0.86
12
(1939-40)
Boat Basin
0.79
-0.84
1.63
5
(1939)
just West of
0.90
-0.37
1.27
3 1/2 (1949)
Inlet
0.59
-0.17
0.76
2
(1951)
0.82
-0.09
0.91
7
(1951-2)
After dredging in
Inlet
0.74
-0.46
1.20
15
(1952-3)
After start of
construction of
East jetty
0.90
-0.61
1.51
16
(1953-4)
After Construc-
tion of West
jetty
1.01
0.87
1.88
12
(1956)
Shinnecock
1.23
-1.10
2.33
12
(1939-40)
Inlet
1.40
-1.49
2.89
3
(1953)
(ocean)
1.89
-1.21
3.10
2/3(1955-6)
TABLE C-2
ESTIMATED ANNUAL AVERAGE WINDS
(From Observations 1940-1959)
Percent
Direction
of Time
N
10
NE
9
E
9
SE
6
S
9
SW
22
W
17
NW
17
Calms
1
TABLE c-3.1 WAVE DATA
(219° -
STATION 46 20 YEARS
WAVE APPROACH ANGLE(DEGREES):
0.
-
29.9
SHORELINE ANGLE = 69. DEGREES AZIMUTH
WATER DEPTH = 10 00 METRES
PERCENT OCCURRENCE(X1000) OF HEIGHT AND PERIOD BY DIRECTION
NEIGHT(METRES)
PERIOD(SECONDS)
TOTAL
0.0-
3.0-
4.0-
5.0-
6.0-
7.0-
8.0-
9.0- 10 11.0-
2.9
3.9
4.9
5.9
6.9
7.9
8.9
9.9
10.9
LONGER
0.49
1497
3446
2000
1471
443
39
8896
0.50
0.99
559
3056
1998
124
8
1.49
5745
42
331
75
-
was
10
1.99
458
2.49
2.50
2.99
3.49
3.50
-
3.99
- 4.49
4.50 - 4.99
5.00 - GREATER
TOTAL
1497 4005 5098 3800 653
$7
0
0
0
0
AVERAGE HS(M) = 0.45 LARGEST HS(M) = 2.21 ANGLE CLASS % = 15.1
(189°-213.9°)
STATION 46 20 YEARS
WAVE APPROACH ANGLE(DEGREES)= 30.0 - 59.9
SHORELINE ANGLE = 69 0 DEGREES AZIMUTH
WATER DEPTH = 10.00 METRES
PERCENT OCCURRENCE(X1000) OF HEIGHT AND PERIOD BY DIRECTION
HEIGHT(METRES)
PERIOD(SECONDS)
TOTAL
0.0-
3.0-
4.0-
5.0-
6.0-
7.0-
8.0-
9.0-
10
11.0-
2.9
3.9
4.9
5.9
6.9
7.9
8.9
9.9
10.9
LONGER
0.49
992
1745
1579
2400
402
0.99
15
1661
3314
627
7184
157
2869
600
with
1013
1.49
9675
304
1582
835
694
1.99
4038
80
342
520
325
2.49
1310
59
340
2.99
176
592
-
15
3.00
3.49
-------------------------
3.50
3.99
4.00 - 4.49
4.50 - 4.99
:
OOOHCONOBUD
OI
5.00 - GREATER
TOTAL
992 3406 3618 2289 2737 6981 2674 180
0
37
0
AVERAGE HS(M) = 0.79 LARGEST HS(M) = 3.62 ANGLE CLASS % = 22.9
(159°- 188.9°)
STATION 46 20 YEARS
WAVE APPROACH ANGLE(DEGREES)=
SHOREI LINE ANGLE = 69.0 DEGREES AZIMUTH
60.0 - 89.9
WATER DEPTH = 10.00 METRES
PERCENT OCCURRENCE(X1000) OF HEIGHT AND PERIOD BY DIRECTION
HEIGHT(METRES)
PERIOD(SECONDS)
TOTAL
0.0-
3.0-
4.0-
5.0-
6.0-
7.0-
8.0-
9.0-
10,
0-
11.0-
2.9
3.9
4.9
5.9
6.9
7.9
8.9
9.9
10.9
LONGER
0.
0.49
569
799
1793
4387
2181
0.50
0.99
788
1298
94
162
266
154
10311
215
4510
1.00
3615
354
1.49
593
489
521
8
189
95
11884
1026
924
198
1.50
-
1.99
446
147
3618
1
66
249
342
354
2.00
2.49
114
131
27
1284
-
70
379
234
2.50
2.99
71
-
56
188
30
799
3.00
3.49
71
-
348
3.50 - 3.99
54
8
90
4.00 - 4.49
17
17
39
4.50
-
4.99
5
- GREATER
TOTAL
569 1587 1488 753 2422 10700 7519 1041 1429 871
AVERAGE HS(M) = 0.76 LARGEST HS(M) = 4.24 ANGLE CLASS % = 28.4
II
Data obtain from U.S.A.C.DE. WES RePORT. Atlantic Coast Hindract
Shallow Water Significant Wave Information
(175)
21
(1590)
Conversion IS as shown below :
(129°)
90
(189°)
120
60
(990) 150
(219)
30
(690)
180
(249)
shoreline
TABLE c-3.2 WAVE DATA
(129°- 158.9°)
STATION 46 20 YEARS WAVE APPROACH ANGLE(DEGREES)= 90.0 - 119.9
SHORELINE ANGLE = 69.0 DEGREES AZIMUTH
WATER DEPTH = 10.00 METRES
PERCENT OCCURRENCE(X1000) OF HEIGHT AND PERIOD BY DIRECTION
HEIGHT(METRES)
PERIOD(SECONDS)
TOTAL
0.0-
3.0-
4.0-
5.0-
6.0-
7.0-
8.0-
9.0-
10,0-
11.0-
2.9
3.9
4.9
5.9
6.9
7.9
8.9
9.9
10.9
LONGER
-
0.49
504
638
602
1517
1442
246
184
499
5632
0.50
-
0.99
819
1254
61
58
864
1290
314
112
1035
5807
1.00 - 1.49
207
715
92
207
354
42
75
458
2150
1.50
-
1.99
87
225
157
128
35
2.00 - 2.49
61
251
119
we
713
10
444
2.50
-
2.99
46
88
3.00 - 3.49
ww
30
$
169
10
48
3.50 - 3.99
1
5
1
8
4.00 - 4.49
4.50 - 4.99
:
:
OHOO
5.00 - GREATER
TOTAL
504 1457 1461 863 1038 3042 3431 679 417 2078
AVERAGE HS(M) = 0.76 LARGEST HS(M) = 4.11 ANGLE CLASS % = 15.0
(99 99 , - 123.7)
STATION 46 20 YEARS
WAVE APPROACH ANGLE(DEGREES)= 120.0 - 149.9
SHORELINE ANGLE = 69.0 DEGREES AZIMUTH
WATER DEPTH = 10.00 METRES
PERCENT OCCURRENCE(X1000) OF HEIGHT AND PERIOD BY DIRECTION
HEIGHT(METRES)
PERIOD(SECONDS)
TOTAL
0.0-
3.0-
4.0-
5.0-
6.0-
7.0-
8.0-
9.0-
10,0-
11.0-
2.9
3.9
4.9
5.9
6.9
7.9
8.9
9.9
10.9
LONGER
-
0.49
321
544
8
669
1430
965
118
251
4306
0.50
-
0.99
455
1131
383
131
764
562
138
1.00 - 1.49
130
MOOUNTO
111
44
3719
576
419
463
183
22
6
1824
1.50
-
1.99
15
147
407
102
13
684
2.00 - 2.49
29
136
246
2.50
8
2.99
5
8
23
3.00
0
3.49
3.50
0
3.99
CK
4.00 - 4.49
4.50 - 4.99
00
5.00 - GREATER
0
TOTAL
321 999 1269 974 1395 3205 1891 315 384
50
AVERAGE HS(M) = 0.74 LARGEST HS(M) = 3.31 ANGLE CLASS % 8 10.8
(69°- 98.9°)
STATION 46 20 YEARS WAVE APPROACH ANGLE(DEGREES)= 150.0 - 179.9
SHORE LINE ANGLE = 69.0
DEGREES AZIMUTH
WATER DEPTH = 10.00 METRES
PERCENT OCCURRENCE(X1000) OF HEIGHT AND PERIOD BY DIRECTION
HEIGHT(METRES)
PERIOD(SECONDS)
TOTAL
0.0- 2.9 3.0- 3.9 4.0- 4.9 5.0- 5.9 6.0- 6.9 7.0- 7.9 8.0- 8.9 9.0- 9.9 10.0- 10.9 11.0- LONGER
0
-
0.49
557 1273 1064 1112
311
0.50
-
0.99
78
766
215
NH
SMA
58
4375
853
1934
-
1.49
3
49
78
-
1.99
2.00 8 2.49
2.50
2.99
8
-
3.00 - 3.49
0
3.50 - 3.99
0
4.00 - 4.49
000000440
- 4.99
5.00 - GREATER
0
TOTAL
557 1351 1833 2014 553
81
0
0
0
0
AVERAGE HS(M) = 0.37 LARGEST HS(M) = 2.09 ANGLE CLASS % = 6.4
TABLE C4
INLET CHANNEL CROSS - SECTIONAL
AREA (BELOW MLW) CHANGES
1955-56
14-15 JUNE 84
JUNE 85
STATION
AREA (FT2)
AREA (FT2)
AREA (FT2)
0+00
4520*
16060
14840
2+00
4200*
17640
18220
4+00
4440
25380
25400
6+00
5700
17940
19500
8+00
5680
15860
14860
10+00
5220
16620
14890
12+00
4400
17020
14420
14+00
4200*
19220
17010
*Not within Inlet Channel, area calculated within jetty
boundaries
TABLE C-5
SHINNECOCK INLET THROAT CROSS - SECTIONAL
AREA AND HYDRAULIC CHANGES
A
R
* DAV
SURVEY
AREA BELOW
HYDRAULIC RADIUS
AVERAGE CHANNEL
DATE
MSL (FT2)
FT.
DEPTH (FT. MSL)
1955-56
5,500
6.76
6.9
JUNE 84
16,600
19.72
20.8
JUNE 85
15,440
19.60
19.3
*DAV = A/T, Where T = Top width of channel
A = Cross Sectional Area
TABLE c-6
Shinnecock Inlet
Shoreline Erosion West of the Inlet
(Long Term Rates)
Equivalent
Land
Land
Range
Loss Rate
Length
Lost
Lost
No.
(Ft./Yr.)
(Ft.)
(Sq.Ft/Yr.) (Acres/Yr.)
047
-14.6
500
-7,300
-0.17
047+500
-17.3
500
-8,650
-0.20
047+1000
-26.4
485
-12,804
-0.29
046B
-24.9
972.5
-24,215
-0.56
046A
-18.0
1,462.5
-26,325
-0.60
046
+ 8.0
2,173
+17,384
+0.40
045
- 3.8
12,123.5
-46,069
-1.06
043
- 0.6
17,349.5
-10,410
-0.24
35,566.0
-118,389
-2.70
Average Recession = -118,389/35,566
= -3.3 Ft./Yr.
TABLE c-7
Shinnecock Inlet Deposition Basin Shoaling Rate
Straight Channel Alignment
Channel Design Depth of -10 ft. MLW
Depth
Depth Of
Deposition
Time to
Volume Shoaled
of
Natural
Basin
Shoal to
in Basin to
Basin
Bottom
Width
Design Depth
Design Depth
(MLW)
(MLW)
(FT)
(DAYS)
(1000 CY)
18
8
500
276
212.8
700
378
292.0
800
429
331.7
20
8
500
361
293.6
700
493
401.8
800
559
455.9
22
8
500
455
386.2
700
619
526.7
800
701
596.9
Channel Design Depth of -12 ft. MLW
18
8
500
210
174.9
700
287
239.5
800
327
272.9
20
8
500
293
254.2
700
402
349.1
800
457
396.8
22
8
500
387
346.6
700
529
474.3
800
600
538.1
TABLE C8
SAMPLING SCHEDULE FOR BEACH FILL MONITORING
Beach Fill
and
Prefill
Postfill 1st Thru 6th Yr
Seventh
Nearshore
Place-
As-
Yr
Fill
ment
Built 3-mo 6-mo 9-mo 12-mo 6-mo
Profiles
X
X
X
Sediment
X
X
X
Profile
X
X
X
X
Sediment
X
X
X
X
Air Photos
X
X
X
X
X
Biological
Samples
X
X
X
X
X
X
X
Borrow
Pre-Fill
Postfill
After Each
Seventh Yr.
Area
Placement
As-Built
Dredging
6 mo
Sediment
Cores
X
X
X
Surface
Samples
X
Biological
Samples
X
X
X
X
REVISED
YEAR 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 60 70 72 74 76
SPRING OCEAN TIDE RANGE - 3.5 FT
a
MEAN OCEAN TIDE RANGE - 2.9 FT
TIDAL RANGE (feet)
NEAP OCEAN TIDE RANGE = 2. FT
2
Shinnecock Bay
at Boat Basin
(mean values)
1
0
Indicates Interpolation in Periods Lacking Data
FIGURE C1 HISTORY OF BAY TIDE RANGE IN SHINNECOCK BAY
(FROM REFERENCE 4)
WIND DIAGRAM
SOUTH SHORE OF LONG ISLAND
20 YR. AVERAGE (1940-1959) 40
44
N
50
(DAYS)
40
M
246
30
20
NEW
105
46 0703
10
LT
tot
0.8
&
OR
13.0
so
WIND
@
R4
4
10N
75
c
W
10%
15%
20 25
711
4.2
E
23.1
350
20
Ki
BE
10 X 10 TO THE INCH. 7 X 10 INCHES
KEUFFEL & ESSER CO. MADE IN USA.
NS
SIE
08
#22
5
0
K·E
LEGEND
VELOCITY RANGE (MPH)
0 TO 12
OVER TO 24
OVER 24T038
OVER 38
FIGURE C2
SHINNECOCK INLET
CROSS SECTION STATIONING
I
STA 12+00
STA 14+00
G
STA 8+00
STA !0+00
REVISED
STA 6+00
STA 4+00
STA 2+00
STA 0+00
ATLANTIC OCEAN
200 0 0
840
SCALE 1":840"
FIGUR 03-9
SHINNECOCK INLET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA 0+00
WEST
EASTT
JETTY
JETTY
O
OFT(MLW)
46 0703
10
10
1.
20
20
10 X 10 TO THE INCH 7 X 10 INCHES
30
30
KEUFFEL & ESSER CO. MADE IN U.S.A.
355 56
JUNE 84
-40
to
&
x
JUNE 85
40
K&
O
200
400
600
800
1000 FT.
REVISED
FIGURE C3-2
SHINNECOCK INLET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA 2+00
=
WEST +10
HO
JETTY
EAST
JETTY JE 117
x
0
0 (FT.MLW) (FT. MLW)
46 0703
-10
10
X
-20
20
10 X 10 TO THE INCH. 7 X 10 INCHES
30
30
KEUFFEL & ESSER CO. MADE IN USA.
5 56
X
JUNE 84
10
JUNE 85
to
K·E
0
200
400
600
800
1000 FT
REVISED
FIGURE C3-3
K&E
10 X 10 TO THE INCH.7 X 10 INCHES
KEUFFEL & ESSER CO. MADE IN U.S.A.
460703
bi
JETTY
70
09-
09
&
Oh
30
20
OH 153M
10
o
0
x
STA 4+00 +
A
X
X
REVISED
200 400 600 800 1000 FT
X
X
*
CROSS SECTIONS
COMPARATIVE CHANNEL
SHINNECOCK INLET
JU JUNE , NE 85
JUNE # 84
to G 1955-56 56 8
FIGURE C3-4
0
70
09
05
70
30
20
01
014
01
SHINNECOCK INLET
COMPAR ATIVE CHANNEL
CROSS SECTIONS
STA 6+00
&
WEST
10
+10
JETH
EAST
JETTY
0
0 FT(MLW)
46 0703
-10
10
-zo
20
X
10 X 10 TO THE INCH.7 X 10 INCHES
30
30
KEUFFEL & ESSER CO. MADE IN U.S.A.
x
-40
955 56
40
JUNE 84
*
&
$ JUNE 85
K&E
50
50
O
200
400
600
800
1000 FT.
REVISED
FIGURE C3-5
SHINNECOCK INLET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA.8+00 STA 8+00
office
WEST
110
+10
DETTY
EAST
JE 117
O
OFT (ALW)
46 0703
10
10
.
X
6
20
20
x
0
301
30
10 X 10 TO THE INCH. 7 X 10 INCHES
KEUFFEL & ESSER CO. MADE IN U.S.A.
-40-
41 To y
40
J UNE 84
*
X
*
4
D
NE
4
85
K·E
50-
1
50
O
200
400
600
0
800
1000 FT:
REVISED
FIGURE C3-6
SHINNECOCK INCET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA. 10+00
WEST
10
JETTY
+10
0
O FT (MLW
46 0703
-10
10
X
zo
X
20
-
X
10 X 10 TO THE INCH. 7 X 10 INCHES
301
30
KEUFFEL & ESSER CO. MADE IN U.S.A.
x
40
Y
10
K·E
955-56
JUNE 5 5 84
50
X
*
JUNE 85
50
O
200
400
600
800
1000 FT.
REVISED
FIGURE C3-7
SHINNECOCK INLET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA 12+00
in
WEST 110
10
JETTY
EAST
JETTY
0
OFT. OFT.(MLW) (MLW)
46 0703
10
10
0
20
30
10 X 10 TO THE INCH 7 X 10 INCHES
30
30
KEUFFEL a ESSER CO. MADE IN U.S.A.
X
40
X
-40
K&E
1355 56
JUNE 84
50
X
*
x
JUNE M E B5
PC
0
200
000
600
008
000 FT
REVISED
FIGURE C3-8
SHINNECOCK INLET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA 14+00
WEST 110
+10
JETTY
0
OFT.(MLU)
46 0703
10
x
10
N
X
-20
zo
10 X 10 TO THE INCH. 7 x 10 INCHES
30
30
KEUFFEL & ESSER CO. MADE IN U.S.A.
-40
-40
1955 56
Is UNE to 84
%
K·E
J E 85
-50
50
0
200
400
600
800
1000 FT
REVISED
FIGURE C3-9
NEW -
TTS
I
i
BEACHES WEST OF
GREAT PECOING BAY
$190,000
SITE
!
SHINNECOCK INLET
ATLANTIC OCEAN
LOCATION MAP
8
WEBT Teams
SHORELINE
CHANGE MAP
-
dge
east BERGUE
NUMBER
SHINNECOCK
0
:
INLET
CASTOORT
WESTMANPTON
SEACH
QUIDBUE
QUOBUE
045
EAST
GENTER -
-
043
ATL ATLANTIC OCEAN
BAY
LIMITS OF ERODING BEACH
MONICHES
GROIN
RANGES
FIELD
046
046A
MORTHES BILEY
046B
047+1000
047+ 500
047
SCALE . FEET
Bear
@
.
-
-
TO
12,300,000
REVIS
BCOLD.AS SHOWN
FIGURE C4
SHINNECOCK BAY
B
046A
0463
04
047A
047B
048
DUNE ROAD
LEGEND
1985
1983
1982
SHINNECOCK INLET
1976
LONG ISLAND. NEW YORK
1968
1956
400
o
800
ATLANTIC OCEAN
SHORELINE
CHANGE MAP
SCALE 1":800'
FIGURE C5
REVISED
LEGEND
FLOOD DELTA MHWLINES
A
1956
x
1968
SHINNECOCK
0
1978
BAY
o
1982
1985
6MLW
MLW
so
E
17min
SHINNECOCK
LEGEND
INLET
EBB DELTA CONTOURS
DEC 1955
JUNE 1989
JUNE 1955
16MLW
BMLW
N/A
12
-IZMLW---
MLW
16MLW
12
30MLN
so MLW
ATLANTIC -12 -12 NLW- OCEAN
SHINNECOCK INLET GDM
EBB AND FLOOD TIDAL
DELTA MOVEMENT
REVISED
FIGURE C6
(DEPOSIT IN BAY)
20,000 CY/YR.
E
6000 CY/YR.
(EROSION)
61,000 CY/YR.
(BEACH EROSION)
247,000 CY/YR.
(TRANSPORT OUT)
300,000 CY/YR
100,000 CY/YR.
(TRANSPORT IN)
(DEPOSIT ON BAR
AND DELTA )
SHINNECOCK INLET
SEDIMENT BUDGET
FIGURE C7
Ac
6
Critical
Flow Area
Hydraulically Unstable
Hydraulically Stable
5
Stable Inlet
Conditions
MAXIMUM CURRENT VELOCITY, Vmax' max' (ft/sec)
Curve
4
-3POW Curre
Vmax = 2.04 0.05
3
Maintenance Criterion
Inlet Closure
Inlet Closure
2
NOTE: This curve represents the typical
shape of the Vₘₐₓ versus Ac
curve. The relationship of the
1
curve to the axes changes from
case to case.
0
1000
5000
10000
50000
CROSS-SECTIONAL FLOW AREA, Ac (ft²)
FIGURE C8
Typical Hydraulic Stability Curve Showing Various Inlet Stability Conditions.
KE
SEMI-LOGARITHMIC 02 CYCLES X 70 DIVISIONS
KEUFFEL & ESSER CO. MADE IN USA.
464973
I
2
3
4
5
6
7
8
9
of
1
2
3
4
5
6
7
8
6
SHINNECOCK NLET
STABILITY ANALYSIS
984 EXISTING
CONDITIONS
4.0
0.05
VMAX=2.04Ac
3.0
VMAX(FPS)
A
956 CONDITIONS
-2.0
AREA, AC (FT2)
104
10³
10
2
3456789
2
3
456789
FIGURE C9
BAY
CHANNEL
N
100
FT.
1100
200
F.
Recommended Channel
Alignment
if
RECOMMENDED
SEDIMENTATION
BASIN
A
OFFSHORE
BAR
/A
SHINNECOCK INLET
NAVIGATION CHANNEL
600 FT.
*
(-8.0 MLW
70
70
-
I
SECTION A-A
RECOMMENDED CHANNEL ALIGNMENT
AND SEDIMENTATION BASIN
FIGURE C10
Tiana
Bay
CONTOIR INTERVAL 10 FEE1
ROBED LIMES REPRESENT 4.000 CONTOONS
DATUM IS MEAN Sta TIVEL
DEPTH CURVES AND SOUNDINGS N FEE: CATUM IS MEAN LOW WATER
SHERI INDI DEPRESENTS THE APPROVALITE .048 C" "gan MISH MAIN
Warner
Islands
" MERY NAMBE (if NOT is 101 MONG 1.1 BCEAN
West Point
Rempasture
AND
07
1811
us CUANT OCARD STA
Flegstalf
San:
Send
Sard
Ponquojae Pl
SOUTHAMPTON
Easi Point
Citiesal Area
Inlet
Paragegui Bridge
Dearn's rivi
Pistact
Shinnecoek
TRANSECT
B
BMH
DUNE
Sand
flock
Recks
TRANSECT
Lando
-
Area to be Dredged
+
Island
Borrow Area Core Locations
33
DUNE
Disposal Area
Profile Locations
Ariana
35
TRANSECT 1
MONITORING LOCATIONS
REVISED
FIGURE C11
COMPUTATION SHEET
Page C1-1 of 8
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by
Date
Checked by
Date
STABILITY CONSIDERATIONS
1. The stability of Shinnecock Inlet was estimated using the
inlet analytical hydraulic model (Reference 1) based on
principles developed by Keulegan (Reference 2). The model
relates the maximum flow velocity in an inlet to the minimum
cross-sectional area of the channel. Application of the
model to Shinnecock Inlet is contingent upon the assumptions
listed below.
a. The inlet cross-sectional area is uniform over the
length of the inlet,
b. The ocean tide can be represented by a sinusoidal
function,
C. The bay water level rises and falls uniformly,
d: There is no substantial inflow to the bay other than
through the inlet,
e. and the bay area is constant over all tide ranges.
The results obtained are considered meaningful in the
identification of possible inlet trends, and not as a basis
for design.
2. The stability analysis is based on the development of a
stability curve representative of conditions at a particular
inlet. The peak of this curve, which plots a relationship
between inlet minimum cross-sectional area and average
maximumcurrent velocity, is known as the critical cross-
sectional area and is interpreted to be the point of incipi-
ent stability. For minimum cross-sectional areas less than
the critical area the flow is governed by frictional forces.
This results in an inlet unstable to changes in flow area or
maximum velocity. When the flow area is reduced by shoaling,
or if the velocity is reduced by changed flow characteristics
the inlet responds by futher reducing area or velocity until
the inlet closes. Conversely, an unstable inlet which starts
to scour, by either a reduction in sediment supply or an in-
crease in velocity, will continue to scour until the critical
flow area is achieved. For cross-sectional areas greater
than the critical area, the flow through the inlet is
governed by the continuity requirement resulting in an inlet
stable to changes in flow area or velocity. In this condi-
tion, any change in cross-sectional area will cause the inlet
to respond by compensating in such a way as to force its
return toward the equilibrium position. A stable inlet can
close, however, if the velocity does not exceed the mainten-
ance criterion defined as the velocity needed to scour sand
deposits from the inlet channel. This velocity is given by
the equation:
0.05
Vmax = 2.04 Ac
These characteristics are shown on the generalized inlet
hydraulic stability curve of Figure 1.
COMPUTATION SHEET
Page C1-2 of 8
Subject STA ANALYSIS
Project SHINNECOCK INLET
Computed by
Date
Checked by
Date
3. Using all available hydrographic survey, bay and ocean
tide data, and a measured bay area of 4.07 X 108 ft2, the
stability curves of Figure 2 were developed. The lower curve
in this figure was developed from 1956 hydrographic and tidal
conditions at Shinnecock Inlet. The minimum inlet cross-sect-
ional area of 5500 ft2 , as determined from the Nov/Dec 1955-
Jan 1956 survey, indicates that the inlet was hydraulically
unstable at that point in time. This is due to the fact that
the minimum area plots on the 'scour' side of the stability
curve. The upper curve of Figure 2 was developed from hydo-
graphic survey and tidal data obtained after the Federal
emergency dredging of June 1984. A minimum cross-sectional
area of 16,600 ft2 was determined for the inlet using the
hydrographic survey of 16 June 1984. This area plots well
in the stable range of the 1984 stability curve, indicating
that the inlet is currently in a hydraulically stable cond-
ition.
4. Information presented in earlier sections of this report
supports the conclusion that the inlet is hydraulically
stable at the present time. Figure C1 shows that the tide
range in Shinnecock Bay, immediately inside the inlet, con-
tinually increased from the time the inlet jetties were
constructed in 1952 until about 1964. After 1964 the rate of
increase appears to level off and fluctuate about an approx-
mate tide range of 3.0 ft. This value is consistent with the
2.9 mean ocean tide range reported by NOAA for Shinnecock
Inlet. The tidal prism, defined as the volume of water
entering the bay, is the product of the bay tide range and
effective bay surface area. An increase in bay tide range is
indicative of an increase in tidal prism, which in turn by
hydraulic continuity is proportional to an increase in
convyance through the inlet entrance, provided the volume of
water exchanged at the other entrances is relatively small
and can be neglected. Therefore it is expected that inlet
minimum cross-sectional area data should show similar trends
to those exhibited by tide range data. It appears that bay
tidal data, and consequently inlet cross-sectional areas,
support the conclusion that the inlet is in a stable mode.
References Cited:
1) O'Brien, M.P. and Dean, R.G. (1972) Hydraulics and Sed-
imentary Stability of Coastal Inlets, Proceedings: 13th
Coastal Engineering Conference.
2) Keulegan, G.H., Tidal Flow in Entrances, Water Level
Fluctuations of Basins in Communications with SEAS, Corps
of Engineers, U.S. Army, June 1967.
3) Czerniak, M.T., (Tetra Tech, Inc.) Emgineering and Envir-
onmental Assessment for the Stabilization and Sand Bypassing
of Moriches Inlet, Prepared for NY District Corps of
Engineers, Contract DACW-51-75-C-0015, Jan 1976.
Computed by
*
6
Ac
Critical
Flow Area
Hydraulically Unstable
Hydraulically Stable
5
Subject STABILITY ANALSIS
MAXIMUM CURRENT VELOCITY, V Vₘₐₓ' max' (ft/sec)
Mode Movement Curve
Stable Inlet
Conditions
4
Date
3
Scour Upward Modernent
Vₘₐₓ = 2.04 AC.05 c
Maintenance Criterion
Inlet Closure
Inlet Closure
COMPUTATION SHEET
2
NOTE: This curve represents the typical
shape of the Vₘₐₓ versus Ac
Checked by
curve. The relationship of the
1
curve to the axes changes from
case to case.
0
1000
5000
10000
50000
Date
Project SHINNECOCK INLET
CROSS-SECTIONAL FLOW AREA, Ac (ft2)
PageC1-50f Page C1-5 8
FIGURE 1.1 Typical Hydraulic Stability Curve Showing Various Inlet Stability Conditions.
PAGECI40F8
10
9
8
7
600
6
6 7 E
5
5
4
3
SHINNECOCK NLET
STAB ITY STABILITY ANALYSIS
4
984 EXIST NG
46 4973
CONDITIONS
3
2
2
1
8 6 9 7
AREA, Ac (FT2)
4
10⁴
6
8
1
SEMI-L SEMI-LOGARITHMIC 02 CYCLES X TO DIVISIONS
Alline
0
MADE IN U.S.A.
5
KEUFFEL & ESSER CO.
4
956 CONDIT ONS
to
V
ADAM
3
3
K·E
2
I
(Sd3) XANX
4.0
3.0
2.0
3
10
-
COMPUTATION SHEET
Page C1-50f 8
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by DMM
Date
Checked by
Date
STABILITY ANALYSIS USING O'BRIEN AND DEAN METHOD
SQUARE 10 THE INCH
REPLETION COEFFICIENT K= I Ac
29 ao
2TTao AB
(EQI.
V
Ken + Kex + fl/4R
FOR 15 JUNE '84 (POST EMERGENCY DREDGING) CONDITIONS :
Ac (FROM FIG, ) = 16,600 FT2
RH = 19.72 FT.
ao = 1.45 F.T. (NOAA)
(USING RH.= = Ac/(W+2D))
ab= 1.30 FT. (TIDE GAGES)
AB = 4.07 x108 F.T2 (MEASURED)
T= = 12.42 HRS (44,700 SEC.)
Ken *Kex = 1.3 CO'BRIEN + DEAN)
f= 0.03
FROM FIG. 4 O'BRIEN + DEAN; USING ab/ao = 0.9, KE= = 1.13
RE- ARRANGING EQ. 1:
lE = [ ( TAc)2 29 - (Ken+Kex)] to 4R
2π KAB ao
4
11
(44700(16,600) 2π (1.13) 4.07*108
(64.4)
-
1.3
4(19.72)
1.45
0.03
le = 4282
USING CONSTANT lE,
K= 44700 Ac
64.4 (1.45)
2π (1.45) 4.07x108
1.3 + (0.03(4282))/4R
K= 1.165*10⁻⁴ Ac
V1.3 + 32.1/R
;
(EQ. 2)
NANY FORM 229 Apr 79
VMAX = 2TTao AB V'MAX
T Ac
= 8.295 x104 V'MAX
;
(EQ.3)
Ae
P= Zab AB = 290 AB (ab/a.) ;
(EQ.4)
= 1.1803 VID a (ab/a.)
COMPUTATION SHEET
Subject
PageC 1- bof E
STABILITY ANALYSIS
Computed by DMM
Project SHINNECOCK INLET
Date
Checked by
Date
15 JUNE 1984, STABILITY CALCULATIONS:
TO THE INCI
(1)
(2)
Ac (Fr2)
RH (FT.)
(3)
K
(4)
V'MAX MAX
(5)
VMAX
(6)
2000
2.48
QMAX
0.062
ab/ao ab 100
-
P (FT3)
I
3000
-
3.72
-
-
0.111
0.105
SQUARE
4000
4.94
2.90
0.167
8700
0.121
1,428 x108
5000
0.150
3.11
6.15
0,228
12440
0.210
0.185
6000
3.48
2,183 r108
7.36
17400
0.294
0,270
0.255
3,73
3.010 x108
7000
8.56
0.363
22380
8000
0.330
0.335
3.91
3.954 x108
9.76
0.435
27370
0.385
0.405
4.780 x106
9000
10.94
0.510
3.99
31920
0.470
0.445
5.550 x105
10000
12.12
4,10
0.586
36900
0.500
0.545
6,433 x108
12000
14.46
4.15
0.745
41500
0.610
0.610
7.200 x108
14000
16.77
4.22
50640
0.910
0.690
0.735
8.675 x108
16000
19.05
4.08
1.079
57120
0.760
0,820
9.678 NO8
18000
21.30
3.94
1.252
63040
0.815
0.885
1.045 1109
20000
23.53
3.76
1.427
67680
0.865
0.930
1.098 x10"
25000
29.99
3.59
1.892
71800
0,955
0.945
3.14
1.127 -10'
30000
34.29
2.337
78500
0.980
0.985
2.71
1.163 x10°
35000
39.44
81300
2,804
0.990
40000
0.990
2.35
1.168 r/o"
44.44
3.277
1.0
82250
0.995
2.07
1.174x109
82800
1.0
1.1803x109
(1) K FROM (EQ.2)
(2) V'MAX. FROM FIG. 3, O'BRIEN + DEAN
(3) VMAX FROM (EQ.3)
(4) QMAX = VMAX xAc
(5) ab/ao FROM FIG. 4, O'BRIEN + DEAN
(6) PFROM (EQ.4)
FOR MAINTENANCE VELOCITY:
NANY FORM 229 Apr 79
VMAX > 2.04 Ac°.05
COMPUTATION SHEET
Subject STABILITY ANALYSIS
Page C1-7of 8
Project SHINNECOCK INLET
Computed by DMM
Date
Checked by
Date
STABILITY ANALYSIS USING O'BRIEN AND DEAN METHOD:
FOR 1955 - JAN 1956 CONDITIONS:
SQUARE 10 THE
Ac= = (FROM FIG. ) 5500 FT2
RH = 6.76 FT
ao = 1.4 FT. (NOAA)
(USING RH = Ac/(W+2D))
ab = 0.35 FT. (SURVEY REPORT)
AB= 4.07*108 FT.2 (MEASURED)
T= = 12.42 HRS. (44700 SEC)
Ken + Kex = 1.3 CO'BRIEN + DEAN)
f=0,03 =
FROM FIG. 4 O'BRIEN AND DEAN, USING ab/ao = 0.25, KE = 0.22
RE -ARRANGING EQUATION 1:
le
= (- TAc ,2 2g - (Ken + Kex)
2IT KAB ao
4R
f
= ( 44700 (5500) ) 64.4 - (1.3)
2TT (0.22) 4.07x10 1.4
]
4(6.76)
0.03
le = 6746 FT.
USING CONSTANT lE,
K= T Ac
2g ao
2πao AB
Ken+Kex + fle/4R
5
(EQ. 1)
K= 44700 Ac 64.4(1,4)
2TT(1.4) 4.07*108 1.3+ 50.6/R
K= 1185 x10-4 Ac
V1.3 + 50.6 /R
;
(EQ.2)
VMAX= 80093 V'MAX
Ac
in
(EQ.3)
NANY FORM 228 Apr 78
P= 2ab AB = 2ao AB (ab/a.)
P = 1.1396x109 (ab/ao)
; (EQ.4)
COMPUTATION SHEET
Page C1-8of of 8
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by DMM
Date
Checked by
Date
1955 - JAN 1956 STABILITY CALCULATIONS
(1)
(2)
(3)
(4)
(5)
(6)
THI DI sr. I DVNOS
Ac (FT.)
RH (FT.)
K
Y'MAX
MAX
QMAX
ab/ao
P(FT3)
2000
2.48
0.051
-
-
-
-
I
3000
3.72
0.092
-
-
-
-
-
4000
4.94
0.139
0.125
2.50
10,000
0.160
1.823 H08
5000
6.15
0.192
0.182
2.92
14,600
0.210
2.393*108
6000
7.36
0.249
0.230
3.07
18,420
0.280
3,191x 10
7000
8.56
0.309
0,285
3.26
22,820
0.350
3,989,10 3,989
8000
9.76
0.372
0.330
3.30
26,400
0.410
4,672.10
9000
10.94
0.438
0.390
3.47
31,230
0,480
5.470 x108
10000
12.12
0.506
0.435
3.48
34,800
0.540
6115410
12000
14.46
0.649
0.540
3.60
43,200
0.660
7.521 x108
14000
16.77
0.798
0.635
3.63
50,820
0.760
8.66 1x108
16000
19.05
0,953
0.710
3.55
56,800
0.830
9.459 110
18000
21.30
1.113
0.775
3.45
62,100
0.890
1.014x10
20,000
23.53
1.276
0.830
3.32
66,400
0.930
1.059*109
25000
29.99
1.714
0.920
2.95
73,750
30,000
0.975
1.111x109
34.29
2.134
0.970
2.59
77,700
0.990
1.128*10
35,000
39.44
2.581
0.990
2.27
79,450
0.995
40,000
1.134Y109
44.44
3.035
0.995
1.99
79,600
1.0
1,1396x109
(1) K FROM (EQ. 2)
(2) V'MAX FROM FIG 3 O'BRIEN + DEAN
(3) VMAX FROM (EQ.3)
(4) QMAX = VMAX x Ac
(5) ab/ao FROM FIG.4, O'BRIEN + DEAN
(6) PFROM (EQ.4)
FOR MAINTENANCE VELOCITY:
NANY FORM 229 Apr 79
VMAX > 2.04 Ac 0.05
(O'BRIEN + DEAN)
COMPUTATION SHEET
Page C2-1 of /
Subject Design wave Analysis - West Jetty
Project SHINNECOCK INLET
Head Section - Existing Design
Computed by
Date 9/86
Checked by
Date
To determine the maximum wave resisted by existing west
jetty head section equation 7-116 SPM pg.205
will be used as follows:
SQUARE X 5 X 5 TO THE INCH
W= = wr H3
KD (Sr-1)3 cot Θ
where
W = weight in pounds of an individual armor
unit in the primary cover layer.
Maximum size of existing nead armor
units is 12 tons.
wr = unit weight (sat. surf.dry) of armor unit
lbs/ft3. - use 165 lbs/f+3
H = maximum design wave height at the
structure in ft.
Sr = specific gravity of armor, relative to water
at the structure Sy= wr/ww
Sr = 165/64.0 = 2.58
ww = unit weight of water, 64.0 lbs / f+3
θ = angle of structure slope
cot - = 1.5
KD = stability coefficient, for rough angular
quarry stone head section, on a 1Von 1.5 H
for a breaking wave
use KD= 1.9
substituting
Himax +124,000)(258-1).(1.5)(.9 = = 1635.1
(165)
Hmax = 11.8 feet
NANY FORM 229 Apr 79
COMPUTATION SHEET
Page C3-1 of 2
Subject Design Current Velocity
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
The maximum velocity of tidal currents in mid channel
In THE INCH
through a navigation opening can be approximated
by Eg 7-128 P9 7-250, SPM:
V= = 4Th
(7-128)
5 -
3TS
SQUAR
where:
V= = maximum velocity at center of opening
T = Period of Tide (12.4 hrs = 44,640 sec)
A = Surface area of bay (16mi² = 446,054,40059 ft)
5 = Cross- sectional area of opening (16,600 sq. ft)
n - range of tides in bay (ft.)
V= 4 (446,054,400) h
3 (44,650)(16,600) (44,650) (16,600)
V= 2.52h
For the estimated bay tidal range resulting
from a 1938 # turricane (Recurring) of 4.0 feet
from Fire Island to Montauk BEC; HP Survey Report)
to velocity is given
V= 2.52(4,0)= = 10.1 ft /sec
: 10 tps is design current velocity at
jetty head section
NANY FORM 228 Apr 70
COMPUTATION SHEET
Page C3-Zof 2
Subject Design Current Velocity
Project SHINNECOCK INLET
Computed by
Date
9 / 86
Checked by
Date
To estimate a maximum probable design current velocity
at the bay shoreline east of the inlet, the
SQUAR 10 THE INCH
Continuity Equation was ut lized.
Az
Z
west Jetty
A,
East Jetty
Q= = VA
Q. = Q2 where Q1 and Q2 are the discharges at
the cross sections 1 and 2
V,A, = V2Az
A22 24,000 ft2
V2 = V, A.
A2
Substituting in computed maximum probable velocity
at the inlet throat and measured cross-sectional areas
V2= 10 fps X 16,600 1:2 = 6.9 fps
24,000 f+2
V2/7 = 7.0 ft /sec.
This velocity will not however control the revetment
design. The revetment design is controlled by wind
generated bay waves shown in computation C5
The D/. revetment design is detailed in Computation
MANY FORM 229 Apr 70
COMPUTATION SHEET
Page C4-1 of 4
Subject DESIGN WAVE ANALYSIS
Project Shinnececk Inlet GDM
WEST / EAST JETTY HEAD SECT
Computed by
Date 9/86
Checked by
Date
10 THE INCI
1 The wave climatology selected for use 19 this
study was available by the U.S. Army Corps
Waterways Experiment Statem on titled
but
-
"Atlantic Coast Hindcast, Shallow Water Significant
Wave Information" (Ref 10), The tables used
SOURP
Were for station 4 46. See Tables C-4.1 € C-4.2
2. Refraction and Shoaling COC tficients were estimated
using a simplified method CRef. 26 , Thefollowing
assumption are implicit in this approach
a. effects of currents are precluded
b. wave wave interaction prestuded
a effects of wave energy reflection anstructs preclude
d. attenuation by friction precludes
E., assumes straight and 11 contones
DIRECTION OF
SIGNIF 11
WAVE 11 REFRACTION? 4/ REFRACT
WAVE APPROACH
WAVE HGT
PERIOD SHOALING SHOALED
30'depth
(sec)
COFF
WAVE HGI
(FT)
KR KR.KS ks
(FT)
@ a @ @
30°-59.9° !
30' 20' 30' 20'
(187°-217°) 21
12.5
9.5
0.85 0.89 10.6 11.1
[45.] 31
60°-89.9°
14.2
11
1,.061.12 15 159
(157-187)
[150]
90° -119.9°
14.2
11
1,06 1.12 15 15.9
(127°-157°)
[15°]
120° - 1499°
10.8
9.5
0.85 0.89 9.2 9.6
NANY FORM 220 Apr 79
97 - 127°
[45]
COMPUTATION SHEET
Page C4-Z01 4
/
Subject
DESIGN WAVE HEIGHT
WEST LEAST JENY HEAD SECT
Project Shinnecock Inlet GDM
Computed by
Date 9/86
Checked by
Date
MAXIMUM
WAVE HEIGHT TABLE (CONT'D):
DIRECTION OF
SIGNIFICANT WAVE KR.Ks REFRACTED
TO THE INCK
WAVE APPROACH
WAVE HGT. 2
PERIOD
SHOALED
30' depth
WAVE H&T
CFT)
(sec)
D
R
(FT)
5 X 5
30' 20'
@20' @ 30
150-179
7.5
6.5
0.6 0.55
4,5 3.6
SQUAR
(67-97)
[75°]
Maximum Wave Height Expected = 16 ft.
NOTES:
II Wave direction, height and period obtained
from WIS tables C-41, C-4,2
21 Wave direction. converted to true north
compass aszimuth using
(1270) (157°) (1870)
120 90
709
WIS
arbitrary angle classification
97°) 50
30 (2179
WIS angle classification
converted to true
(670) 180
(2470)
north aszmati
The
Shoreline orientation
N
31 average of WIS wave angle section measured
from the shore normal for use in
refraction analysis Ret 26,
NANY FORM 220 Apr 79
41 Refraction and shoaling coefficient KR'Ks
obtain from Ref. 26
COMPUTATION SHEET
Page C4-3 of 4
DESIGN WAVE ANALYSIS-
Subject
Project
WEST JETTY HEAD SECTION
Computed by
Date 9 /86
Checked by
Date
The design wave which allows for the full impact of
TO THE INCH
a breaking wave upon the structure (see Chap. 7 Section 7.a.
pg 7-202 5 5PM) and is limited by the depth
of water above the existing bo Hom (H=0.78d, Eg 2-91
Pg 2-130, SPM) is computed assuming a non-linear
5X5
-
surface profile as shown below.
SQUAR'
el + 9MLW
H
08H
SWL
10.2H
MLW
111
d
WEST JETTY HEAD
SECTION
(
EXISTING BOTTOM
PROPOSED BASIN
CUT
TRY SWL = +8 FT MLW
Depth at bar(ds) = 8+14 8 = 22 ft
Depth limited Wave height = 0.78/22= = 17.16 ft
Depth of trough below SWL = 0.2 117.16)= 3.43.ft
elevation of trough = +8 ML, - 3.4 = 4.6 Ft MLW
Full Impact Is Not Achieved
IMPROVED
+4,6 ft MLW < + 9.0 ft MLW
Full
Depth limited
Depth of trough
Elevationof
Impact
SWL
as
wave height
below SWL
trough
Achieved
+
8.0 MLW
22
17.16
3.43
4.6
NO
+
0.0
24
18,7
317
6.3
NO
+
12.0
26
20.3
4.1
7.9
NO
+
13.0
27
21.1
4.2
8.78
NO
+
14.0
28
21,8
4,4
9.6
NO
0° Full IMPACT 15 achieved for
NANY FORM 220 Apr 79
design & WL between +13 MCW and +14MLW
TRY SWL =+13.2
13.2
27.2
21,2
4.24
8.95
YES
Depth Limited Wave Height
= 21.2 H.
(Improved Condition)
COMPUTATION SHEET
Page C4-4 of 4
Subject DESIGN WAVE ANALYSIS
WEST /EAST JENY HEAD
Project shinnecock Inlet 60m
Computed by
Date 9/86
Checked by
Date
SOUAR 5 5 X 5 TO THE INCH
EXISTING CONDITION Waves Brea king on Existing Bar
SWL
ds Depth limited Depth through EL of Full Import
wave Height below SWL Trough Achieves
+8,0 MLW 16'
12.5'
2.5'
+5.5 MLW NO
+10,0
13'
K.O'
2.8'
+7,2MW No
T12.0
20'
15.6'
3.1'
+8,9 Men VE,
+12.5
20.5'
16.0'
3.2'
+9.3 MCW NO
: Full IMPACT IS ACHIEVED FOR EXISTING COND.
SWL = 712 ft MCW
DEPTH LIMITED WAVE HEIGHT = 15.6FT.
(EXISTING CONDITION)
Design wave Height for Jetty Head Section = 16 ft.
Based on N.I.S. Hindcast
and Refraction- Shallowing Analysis.
NANY FORM 220 Apr 79
COMPUTATION SHEET
Page C5-/or i
Subject Design Wave Height for
Proposed Revetment
Project SHINNECOCK INLET
Computed by
Date 9 /86
Checked by
Date
To stabilize the bayside of the dune and prevent
material losses, a revetment was designed using
SOLLAR X 5 X 5 TO THE INCH
Corps criteria Although the shoreline in the vicinity
of the proposed revetment is sheltered from the
ocean waves it is not sheltered from waves
generated within the bay Using the procedures
published in the SPM and ETL 1110-2-211 for
generation of shallow water waves, breaking wave
was computed.
Estimated bay depth =8.0f. MLW
Surge +Tide level
F+7.3 ft MLW
(+6. oft. NEVD)
Fetch length
= 14,500 ft
Wind velocity UA = 79 mph
using procedures in
ETL 1110-2-221
h
(water depth) (wave height) (wave period) Figure (SPM
H
T
15
3.3
32
3-29
Assume wave height = 3.3 ft
wave period = 3.2 see
NANY FORM 229 Apr 79
COMPUTATION SHEET
Page 661 of 1
Subject CHANNEL WIDTH DESIGN
Project SHINNECOCK INLET
Computed by LMK
Date 9/86
Checked by
Date
The width of the navigation channel at Shinnecock
Inlet was determined by the procedure given in
EM 1110-2-1615 Hydraulic Design of Small Boat Harbors.
SQUAR I 515 TO THE INCH
Two design vessels one fishing vessel and one recreational
vessel, were chosen for the two-way traffic
The beam width of the design recreational vessel is 15 ft.,
and the beam width of the design commercial vessel
is 22 ft. Allowances for outriggers used by the
commercial fishing vessels was included in the channel
width.
CHANNEL WIDTH (VESSELS WITH VERY GOOD MANEUVERABILITY)
BANK CLEARANCE LANE (COMMERCIAL) 150 90x 22' 88 33 ft.
*
MANEUVERING LANE (COMMERCIAL)
16090 X 22' 88 35 ft.
70 ft. for Outriggers
= 70 ft
SHIP aEARANCE LANE (COMMERCIAL) 80% X 22'= = 13 ft
MANEUVERING LANE (RECREATIONAL) 160 % X 15' = 24 ft.
BANK CLEARANCE (RECREATIONAL) 150% X 15' 03 23 ft.
*
203 ff.
The Design Channel Width will be 200 ft.
X
Bank Clearance as Per Cent of the Vessel beam were increased
due to existance of the rubble mound jetties and the
ad verse Weather conditions,
MANY FORM 229 Apr 79
COMPUTATION SHEET
Page C7-1 of S
Subject
shoaling Analysis for a Channel Basin Cut
Through An offshore Bar-Tramport Ratis
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
ID THE INCP
TRANSPORT RATIO METHOD
FOR
SHOALING OF A DREDGED CUT
THROUGH THE BAR SEAWARD OF AN INLET
SOIMM
This method was developed by Dr. Cyril Galvin, under contract
DACW51-79-C-0046 for the New York District, specifically with
reference to Moriches Inlet.
Assumptions. This is an analysis of the shoaling likely to
occur in a cut through a typical ocean bar around the mouth of an
inlet. The analysis depends on the following assumptions:
1. Sand is set in motion by the shoaling and breaking of waves.
2. Once set in motion, the sand is transported by whatever net
currents exist at the site. For the dredged channel, these currents
are assumed to be mostly due to the ebb flow of the tidal prism
coming out of the inlet.
3. Wave motion is adequately described by linear theory.
4. Sediment motion depends on the bottom shear which is
primarily due to the bottom water motion under shoaling and breaking
waves.
General Equation. The purpose of this analysis is to compare
the sediment transport potential in the dredged cut with the
sediment transport on the bar before dredging. The general equation
relates sediment transport to the bottom shear which initiates
sediment motion and the ambient current which moves the sediment
whose motion has been initiated.
Sediment Transport Rate = Coefficient X Bottom Shear X
Ambient Current (1)
Since this analysis compares two conditions in the same
environment, it is assumed that the coefficients for pre and post
dredging conditions are the same. Thus, the ratio of post dredging
to pre-dredging sediment transport is:
Transport ratio = Bottom Shear Ratio X Ambient Current Ratio (2)
NANY FORM 229 Apr 79
Bottom Shear Ratio. Shear is proportional to the bottom
velocity squared.
2
τ = constant X U
(3)
COMPUTATION SHEET
Page C7-2 of 8
Subject Transport Ratio Method
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
The bottom water velocity under linear waves is sinusoidal, and the
ID THE INCI
peak veloc ty, U, will be used to represent this bottom velocity. In
shallow water, for linear theory,
me
(4)
5
If we use a subscript 1 to indicate the condition before dredging and
SQUARI
subscript 2 to indicate the condition after dredging, then the bottom
shear ratio is
t₂ = U²
(4)
T1
= - di
(5)
From conservation of energy flux for linear waves in shallow water,
(6)
So the bottom shear ratio turns out to depend entirely on the ratio
of pre to post dredging depths
(d) LilE T2
(7)
Ambient Current Ratio. The general equation (1) is blind to
whatever causes the ambient current on the bar and dredged cut. For
the case of the dredged cut in the bar opposite an inlet, it is
assumed that the dominant current is due to the ebb tide. The
general relation for the current velocity is
V = Q/A
(8)
where Q is the discharge and A is the channel area. For the
two-dimensional unit channel, A equals depth times 1 foot. So the
ambient current ratio is,
MANY FORM 229 Apr 19
V₂ = Q₁ d₁ = Q.
(9)
assuming that the discharge will remain the same after dredging and
the ambient current ratio is
(10)
COMPUTATION SHEET
Page 67-3 of 8
Subject Transport Ratio Method
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
Transport Ratio. It is now possible to combine the bottom shear
ratio with the ambient current ratio to get the transport ratio, post
e 13 THE
dredging to pre dredging conditions. For the case where Q, = O2 in
(10),
Transport Ratio = (d,/d₂)⁵/2
(11)
-
MSL
SQUARI
d₁
d₂
Natural Bottom
S
Bottom of Dredged
Basin
This ratio may be interpreted as follows, where d and d are
defined by the above figure The table evaluates equation (11) for
given values of d₁/d₂, the ratio of pre to post dredging depth,
measured from Mean Sea Level.
d,
Transport
Ratio
21
0.25
0.031
0.5
0.18
0.7
0.41
0.8
0.57
0.9
0.77
0.95
0.88
The transport ratio is a measure of potential for transporting
sediment in the cut after dredging, relative to sediment transport
before dredging. For example, if the ratio is 1.0, then as much sand
will be taken away by the tidal flow as is brought to the channel.
However, as can be seen from equation (11), the only time the
transport ratio will be 1.0, equation is when d.= d₂, that is, the
channel is not deepened at all.
If the dredged depth is double the natural depth, & /d₂equals
0.5, then the table indicates the transport ratio is 0.18, or roughly
the potential to transport out one cubic yard for every 6 cubic yards
NANY FORM 228 Apr 70
carried in from the sides of the channel (which are assumed to remain
at pre dredging depth, d1).
NANY FORM 220 Apr 70
30HAR!
5%5
TO THE INCH
The following is an example calculation for 9 500 fA we deposition basin.
The natural depth of the shoal is 8.0 A MUW
channel design depth
is -12.0 ft MLW
Computed by
dredge depth
15-18.0 ft MLW
Gross Longshore Trans port Volume 400,000 cy /yr
Tranport By-Passing the Inlet Below - 18.0 H MLW = 2.8%
SI
SHOULING COMPUTATION FCR 1986
FOR A
500. FOOT WICE RASIA
TRANSPORT RATIC METHOD
Date
Subject TRANSPORT RATIO METHOD
INFLGW
CUT CF CHANNELCHANNEL
CHANNEL
NEW
CUMULATIVE
DEPTH
TRANSPORT
TRANSPORT
TRANSPORT
SHCAL
DEPTH
CHANNEL
VOLUME
CFPTH
RATIC
VOLUME
RATIC
VOLUME
VOLUME
SHOALED
DEPTH
DAY
SHOALED
(FT.MLW)
(CU.TDS./DAY)
(CL.YOS./DAYIECU. YDS.)
(FT./DAY)
EFT.ML
(CU.YDS.)
18.00
0.445
1065.3
0.132
140.3
925.0
0.0263
17.98
1.
925.0
9186
17.98
0.446
1065.3
0.133
140.9
924.5
0.0264
17.95
2.
1849.4
17.95
0.946
1065.3
0.133
101.4
924.0
0.0264
17.93
3.
2773.3
17.93
0.447
1065.3
0.134
141.9
923.4
0.0264
17.90
4.
3696.7
17.00
0.44P
1065.3
0.134
142.4
922.9
0.0264
17.87
5.
4619.5
17.87
0.948
1065.3
0.135
142.7
922.4
0.0265
17.85
6.
5541.9
17.45
0.445
1065.3
0.135
143.5
921.9
0.0265
17.82
7.
6463.7
17.82
0.450
1065.3
0.136
144.0
521.3
0.0265
17.79
A.
7385.0
COMPUTATION SHEET
17.79
0.450
1065.3
0.136
149.5
920.8
0.0265
17.77
9.
8305.7
17.77
0.051
1065.3
0.137
145.1
920.2
0.0265
17.74
10.
9225.9
17.74
0.452
1065.3
0.137
145.6
919.1
0.0266
17.71
11.
10145.5
17.71
0.452
1065.3
0.138
196.1
989.2
0.0266
17.69
12.
11064.6
Checked by
17.69
0.453
1065.3
0.138
145.7
918.6
0.0266
17.66
13.
11983.2
17.66
0.454
1065.3
0.135
147.2
914.1
0.0266
17.63
14.
12901.2
17.63
0.054
1065.3
0.139
147.8
917.5
0.0267
17.61
15.
13618.7
17.61
0.455
1065.3
0.140
148.9
916.9
0.0267
17.58
16.
14735.6
17.58
0.456
1065.3
0.140
148.9
916.4
0.0267
17.56
17.
15651.9
17.56
0.456
1065.3
0.141
149.5
915.8
0.0267
17.53
1P.
16567.7
17.53
0.057
1065.3
0.141
150.1
915.2
0.0268
17.50
19.
17482.9
17.50
0.95P
1065.3
0.142
157.6
914.7
0.0268
17.47
20.
18397.5
17.47
0.459
1055.3
0.142
151.2
914.1
0.0268
17.45
21.
19311.5
17.45
0.455
1065.3
0.143
151.8
913.5
0.0268
17.42
22.
20225.0
17.42
0,460
1065.3
0.143
152.4
912.9
Project SHINNECOCK INLET
0.0268
17.39
23.
21137.9
17.39
0.461
1065.3
0.144
153.0
912.3
0.0269
17.37
24.
22050.2
17.37
0.461
1065.3
0.145
153.6
911.8
0.0269
17.34
25.
22961.9
Date
17.34
0.462
1065.3
0.145
154.1
911.2
0.0269
17.31
26.
23873.0
17.31
0.463
1065.3
0.146
154.7
910.6
0.0269
11.29
27.
24783.5
17.29
0.463
1065.3
0.146
155.3
980.0
0.0270
17.26
28.
25693.4
17.26
0.464
1065.3
0.147
156.0
909.4
0.0270
17.23
29.
26602.7
Page 74 4 of 8
COMPUTATION SHEET
Page C75 of 8
Subject TRANS PORT RATIO METHOD
Project SHINNECOCK INLET
Computed by
Date
9/86
Checked by
Date
1 S iNI
CUMULATIVE
VOLUME
SHOALED
(CU.YDS.)
27511.4
28419.5
29326.9
30233.8
31140.0
32045.6
32950.5
33854.8
34758.5
35661.5
36563.9
37465.6
38366.6
39267.0
40166.8
41065.8
41964.2
42861.9
43758.9
44655.2
45550.8
46445.7
47339.9
48233.4
49126.2
50018.3
50909.7
51800.3
52690.2
53579.3
54467.7
55355.4
56242.3
57128.4
58013.8
58898.4
59782
60665.3
61547.5
62429.0
63309.7
64189.5
65068.6
65946.9
66824.3
67700.9
68576.7
69451.6
70325.7
6'86112
72071.3
885
SOHARI
DAY
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
45.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
6P.
69.
70.
71.
72.
73.
74.
75.
76.
77.
76.
79.
80.
NEW
CHANNEL
DEPTH
(FT.MLW)
17.21
17.18
17.15
17.13
17.10
17.07
17.04
17.02
16.99
16.96
16.94
16.91
16.88
16.85
16.83
16.80
16.77
16.74
16.72
16.69
16.66
16.63
16.61
16.58
16.55
16.52
16.50
16.47
16.44
16.41
16.39
16.36
16.33
16.30
16.27
16.25
16.22
16.19
16.16
16.14
16.11
16.08
16.05
16.02
15.99
15.97
15.94
15.91
15.88
15.85
15.83
CHANNEL
DEPTH
SHOALED
(F1./DAY)
0.0270
0.0270
0.0271
0.0271
0.0271
0.0271
0.0272
0.0272
0.0272
C.0272
0.0273
0.0273
0.0273
0.0273
0.0274
0.0274
0.0274
0.0274
0.0275
0.0275
0.0275
0.0275
0.0276
0.0276
0.0276
0.0276
0.0277
0.0277
0.0277
0.0277
0.027P
0.0276
0.0276
0.0276
0.0279
0.0279
0.0279
0.0280
0.0280
0.0280
0.0280
0.0281
0.0261
0.0261
0.0261
0.0282
0.0262
0.0282
0.0282
0.0283
0.02P3
YOS.)
SHOAL
908.7
908.1
507.5
6'905
906.3
905.6
905.0
904.4
503.7
903.1
901.8
901.1
SHCALING COMPUTATION FOR 1586
OF CUT.OF CHANNELCHANNEL
VOLUME
902.4
900.4
8*668
899.1
898.4
897.1
897.1
896.4
895.7
895.0
894.3
893.6
892.8
892.1
891.4
690.7
989.9
869.2
838.5
867.7
886.9
846.2
855.4
884.7
883.9
883.1
862.3
881.5
A*0.7
879.9
879.1
878.3
+77.5
876.7
875.8
875.0
874.1
E73.3
A72.4
TRANSPORT
VOLUME
156.6
157.2
157.8
15..4
159.0
159.7
160.3
160.5
161.6
162.2
162.9
163.5
164.2
164.9
165.5
166.2
166.5
167.6
168.3
164.9
169.6
170.3
171.0
171.8
172.5
173.2
173.9
174.6
175.4
176.1
176.9
177.6
1704
170.1
179.9
180.6
191.4
182.2
183.0
183.8
164.6
185.4
196.2
187.0
187.9
188.V
189.5
190.3
151.2
192.0
192.9
A 500. FOOT WICE BASIN
TRANSPORT RATIC METHOD
TRANSPORT
RATIC
0.147
0.148
0.149
0.149
0.150
0.150
0.151
0.152
0.152
0.153
0.153
0.154
0.155
0.155
0.156
0.156
0.157
0.158
0.158
0.159
0.160
0.160
0.161
0.162
0.162
0.163
0.164
0.164
0.165
0.166
0.166
0.167
0.168
0.169
0.169
0.170
0.171
0.172
0.172
0.173
0.174
0.174
0.175
0.176
0.177
0.178
0.17A
0.179
0.180
0.181
0.182
INFLOW
TRANSPORT
VOLUPE
(CU.VDS./DAY)
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
8065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
FOR
IS
CONTINUED
DEPTH
RATIC
0.465
0.466
0.46E
0.467
0.468
0.469
0.465
0.470
0.471
0.472
0.472
0.473
0.474
0.475
0.475
0.476
0.477
0.478
0.478
0.975
0.480
0.481
0.482
0.482
0.483
0.484
0.485
0.486
0.9H6
0.487
0.488
0.489
0.490
0.491
0.491
0.492
0.493
0.494
0.495
0.496
0.496
0.497
0.498
0.499
0.500
1050
0.502
0.503
0.503
0.504
0.505
NANY FORM 229 Apr 79
DEPTH
(FT.MLM)
17.23
17.21
17.18
17.15
17.13
17.10
17.07
17.04
17.02
16.99
16.96
16.94
16.91
16.88
16.85
16.83
16.80
16.77
16.74
16.72
16.69
16.66
16.63
16.61
16.58
16.55
16.52
16.50
16.47
16.44
16.41
16.39
16.36
16.33
16.30
16.27
16.25
16.22
16.19
16.16
16.14
16.11
16.08
16.05
16.02
15.99
15.97
15.94
16051
15.88
15.85
NANY FORM 228 Apr 79
SOHAR!
515
ID THE 000
SI
SHCALING COMPUTATION FOR 1986
FOR A
500. FOOT WICE EASIA
TRANSPORT RATIC METHOD
CONTINUED
Computed by
INFLOW
CUT OF CHANNELCHANNEL
DEPTH
CGANNEL
TRANSPORT
NEW
TRANSPORT
TRANSPORT
CUMULATIVE
SHCAL
DEPTH
DEPTH
RATIC
CHANNEL
VOLUPE
RATIC
VOLUME
VOLUME
VOLUME
(FT.MLW)
SHOALED
DEPTH
(CU.VOS./DAY)
DAY
SHOALED
YOS.)
(FT./DAY)
(FT.MLW)
(CU.YOS.)
15.83
0.506
1065.3
0.182
193.1
15.80
#71.6
0.507
0.0283
1065.3
15.80
81.
72942.8
0.183
194.6
15.77
070.7
0.508
0.0264
15.77
1065.3
82.
0.184
73813.5
195.5
15.74
869.8
0.509
0.0284
1065.3
15.74
83.
0.185
74683.3
15.71
85604
869.0
0.510
0.0284
1065.3
15.71
84.
0.186
75552.2
197.2
15.68
668.1
0.511
0.0284
1065.3
15.68
85.
0.196
76420.2
198.1
15.66
867.2
0.512
0.0285
1065.3
15.66
86.
0.147
77287.3
199.0
15.63
866.3
0.513
0.0265
1065.3
15.63
87.
0.18e
78153.5
199.9
15.60
865.4
0.514
0.0285
1065.3
15.60
88.
0.189
79018.8
200.9
864.4
0.0285
15.57
15.51
0.514
89.
1065.3
79883.2
0.190
201.8
863.5
0.0286
15.54
15.54
0.515
1065.3
90.
0.191
202.7
80746.7
862.6
15.51
0.0286
0.516
15.51
1065.3
91.
0.192
81609.3
203.6
F61.7
0.02A6
15.48
15.48
Date 9 / 86
Subject TRANSPORT RATIO METHOD
0.511
1065.3
0.193
92,
204.6
8247069
867.7
0.0266
15.46
0.518
15.46
1065.3
93.
0.193
83331.6
205.5
859.8
0.0287
15.43
15.43
0.519
1065.3
94.
0.194
84191.3
206.5
858.8
0.0287
15.40
15.40
0.520
1065.3
0.195
95.
20704
85050.1
457.9
15.37
0.0207
15.37
0.521
1065.3
96.
0.196
85907.9
208.4
856.9
0.0288
15.34
0.522
15.34
1065.3
97.
0.198
86764.7
209.4
655.4
0.0268
15.31
0.523
15.31
1065.3
98.
0.198
87620.6
210.0
854.9
0.0268
15.28
15.28
0.524
1065.3
95.
0.199
88475.5
211.4
653.9
0.0288
15.26
15.26
0.525
1065.3
100.
0.200
212.4
89329.4
852.9
0.0289
15.23
15.23
0.526
1065.3
101.
0.201
213.4
90182.3
851.5
0.0289
15.20
15.20
0.527
1065.3
102.
0.202
91034.2
214.4
850.9
0.0289
15.17
0.528
15.17
1065.3
103.
0.203
215.4
91885.0
849.9
0.0289
15.14
15.14
0.525
1065.3
104.
0.204
92734.9
216.4
849.9
0.0290
15.11
0.530
15.11
1065.3
105.
0.205
93583.7
217.5
847.8
0.0290
15.08
15.08
COMPUTATION SHEET
0.531
1065.3
106.
0.206
94431.5
214.5
846.8
0.0290
15.05
0.532
15.05
1065.3
107.
0.207
95278.3
219.6
845.7
0.0291
15.02
0.533
15.02
1065.3
108.
0.20P
96123.9
220.6
844.7
0.0291
14.99
14.99
0.534
1065.3
109.
0.209
221.7
96968.6
643.6
0.0291
14.57
14.97
0.535
1065.3
110.
0.210
97H12.1
Checked by
222.8
P42.5
0.0291
14.54
14.94
0.536
1065.3
111.
0.211
98654.6
223.9
841.4
0.0292
14.91
0.537
14.91
1065.3
0.212
112.
225.0
59496.0
640.3
0.0292
14.88
0.538
14.88
1065.3
113.
0.213
100336.3
226.1
839.2
0.0292
14.85
14.85
0.539
1065.3
114.
0.214
101175.5
227.2
83H.8
0.0292
14.82
0.540
14.82
1065.3
115.
0.215
102013.6
228.3
837.0
0.0293
14.79
0.542
14.79
11€.
1065.3
0.216
102650.5
229.4
835.9
0.0293
14.76
0.543
14.76
1065.3
117.
0.217
103686.4
230.6
834.7
0.0293
14.73
14.73
0.544
1065.3
118.
0.218
104521.1
231.7
@33.6
0.0294
14.70
119.
19.70
0.545
105354.6
1065.3
0.219
232.9
832.4
0.0294
14.67
Project SHINNECOCK INLET
14.67
0.546
1065.3
120.
0.220
106187.0
234.0
631.3
0.0294
14.64
14.64
0.547
121.
1065.3
0.221
107018.2
235.2
M30.1
0.0294
14.62
10.62
0.548
122.
1065.3
0.222
107848.3
236.4
H2H09
0.0295
Date
14.59
14.59
0.549
123.
1065.3
0.223
108677.2
237.6
621.7
0.0295
14.56
14.56
0.550
124.
1065.3
0.225
109504.8
238.8
826.5
0.0295
14.53
14.53
0.551
1065.3
125.
0.226
110331.3
240.0
825.3
0.0295
14.50
14.50
0.553
126.
1065.3
0.227
111156.6
241.2
Page 6 of 8
P24.1
0.0296
14.47
14.47
0.554
1065.3
127.
0.228
242.5
111980.6
822.9
0.0296
10.44
14.94
0.555
1065.3
124.
0.229
112003.4
243.7
421.6
0.0296
14.41
14.41
0.556
1065.3
129.
0.230
113625.0
200.9
P20.4
0.0296
14.38
130.
114445.3
NANY FORM 229 Apr 79
SOUAR'
18
" IHI INIT
SI
SHCALING COMPUTATION FOR 1986
FOR A
5000 FOOT WIDE BASIN
TRANSPORT RATIC METHCD
CONTINUED
Computed by
INFLCE
CUT OF CHANNELCHANNEL
CHANNEL
NEW
CUMULATIVE
DEPTH
TRANSPORT
TRANSPORT
TRANSPORT
SHCAL
DEPTH
CHANNEL
VOLUME
DEPTH
RATIC
VOLUME
RATIC
VOLUME
VOLUME
SMOALED
DEPTH
DAY
SHOALED
(FT.MLN)
(CU.YDS./DAY)
YOS.)
(FT./DAY)
(FT.MLW)
(CU.YDS.)
14.38
0.557
1065.3
0.232
246.2
819.1
0.0297
14.35
131.
115264.3
14.35
0.558
1065.3
0.233
247.5
817.8
0.0297
14.32
132.
116082.1
14.32
0.559
1065.3
0.234
248.8
816.5
0.0297
14.29
133.
116898.6
14.29
0.561
1065.3
0.235
250.1
815.2
0.0297
14.26
834.
117713.8
14.26
0.562
1065.3
0.236
251.4
813.9
0.0298
14.23
135.
118527.7
14.23
0.563
1065.3
0.238
252.7
812.6
0.0298
14.20
136.
119340.3
14.20
0.564
1065.3
0.239
254.0
811.3
0.0298
14.17
137.
120151.5
14.17
0.565
1065.3
0.240
255.3
610.0
0.0296
14.14
13A.
120961.4
14.14
0.566
1065.3
0.241
256.1
808.6
0.0299
14.11
139.
121770.0
14.11
0.568
1065.3
0.243
258.0
807.3
0.0299
14.08
140.
122577.2
Subject TRANSPORT RATIO METHOD
14.08
0.569
1065.3
0.244
259.4
805.9
0.0299
14.05
141.
123383.1
14.05
0.570
1065.3
0.245
260.8
804.5
0.0299
14.02
142.
124187.5
14.02
0.571
1065.3
0.247
262.2
803.1
0.0300
13.99
143.
124990.6
13.99
0.572
1065.3
0.248
263.6
801.1
0.0300
13.96
144.
125792.3
13.96
0.574
1065.3
0.249
265.0
800.3
0.0300
13.93
145.
126592.5
13.93
0.575
1065.3
0.251
266.4
798.9
0.0300
13.90
146.
127391.3
13.90
0.576
1065.3
0.252
267.9
797.4
0.0301
13.87
147.
128188.7
Date 9/86
13.67
0.577
1065.3
0.253
269.3
796.0
0.0301
13.84
148.
128984.6
13.84
0.579
1065.3
0.255
270.8
794.5
0.0301
13.81
149.
129779.1
13.81
0.580
1065.3
0.256
272.3
793.0
0.0301
13.78
150.
130572.1
13.78
0.581
1065.3
0.257
213.4
791.6
0.0302
13.75
151.
131363.6
13.75
0.582
1065.3
0.259
275.3
190.0
0.0302
13.72
152.
132153.6
13.72
0.584
1065.3
0.260
276.8
788.5
0.0302
13.69
153.
132942.1
13.69
0.585
1065.3
0.262
278.3
767.0
0.0302
13.66
154.
133729.0
13.66
0.586
1065.3
0.263
279.8
785.5
0.0303
13.63
155.
134514.4
13.63
0.598
1065.3
0.265
291.4
793.9
0.0303
13.60
156.
135298.3
COMPUTATION SHEET
13.60
0.589
1065.3
0.266
2H3.0
782.3
0.0303
13.57
157.
136080.6
13.57
0.590
1065.3
0.268
284.5
780.8
0.0303
13.54
158.
136661.3
13.54
0.592
1065.3
0.265
286.1
779.2
0.0303
13.51
159.
137640.4
13.51
0.593
1065.3
0.271
287.1
111.6
0.0304
13.48
160.
138418.0
Checked by
13.48
0.594
1065.3
0.272
289.4
775.4
0.0304
13.45
161.
139193.9
13.45
0.596
1065.3
0.274
291.0
77463
0.0304
13.42
162.
139968.1
13.42
0.597
1065.3
0.275
292.6
172.1
0.0304
13.39
163.
140740.7
13.39
0.598
1065.3
0.277
294.3
771.0
0.0304
13.36
164.
141511.7
13.36
0.600
1065.3
0.278
296.0
769.3
0.0305
13.33
165.
142281.0
13.33
0.601
1065.3
0.280
297.7
767.6
0.0305
13.30
166.
143048.5
13.30
0.602
1065.3
0.282
294.4
765.9
0.0305
13.27
167.
143814.4
13.27
0.604
1065.3
0.283
301.1
764.2
0.0305
13.24
168.
144578.6
13.24
0.605
1065.3
0.285
302.8
762.5
0.0305
13.21
169.
145341.0
13.21
0.601
1065.3
0.286
304.6
Project SHINNECOCK INLET
760.7
0.0306
13.18
170.
146101.6
13.18
0.608
1065.3
0.288
306.4
758.9
0.0306
13.14
171.
146660.5
13.14
0.609
1065.3
0.290
308.1
757.2
0.0306
13.11
172.
147617.7
13.11
0.611
1065.3
0.291
309.9
Date
755.4
0.0306
13.08
173.
148373.0
13.08
0.612
1065.3
0.293
311.9
753.6
0.0306
13.05
174.
149126.5
13.05
0.614
1065.3
0.295
313.6
751.7
0.0307
13.02
175.
149878.1
13.02
0.615
1065.3
0.291
315.4
749.9
0.0307
12.99
176.
150628.0
12.99
0.617
1065.3
0.298
317.3
748.0
0.0307
12.96
177.
151375.9
Page C7-7 of 8
12.96
0.618
1065.3
0.300
319.2
746.1
0.0307
12.93
178.
152122.0
12.93
0.619
1065.3
0.302
321.1
744.2
0.0307
12.90
175.
152866.2
NANY FORM 229 Apr 70
SQUAR
10'TH' INCL
$8
SHCALING COMPUTATION FOR 1986
FOR
A
500. FOOT WICE HASIA
THANSPORT RATIC METICO
CONTINUED
Computed by
INFLOW
CLT OF CHANNELCHANAEL
CHANNEL
NEW
DEPTH
CUMULATIVE
TRANSPORT
TRANSPORT
TRANSPORT
SHGAL
DEPTH
CHANNEL
VOLUME
DEPTH
RATIC
VOLUME
RATIC
VOLUME
VOLUME
SHOALED
DEPTH
DAY
SHOALED
(FT.MLW)
BCU.YDS./DAY)
YDS.)
(FT./DAY)
(FT.MLW)
(CU.VDS.)
12.90
0.621
1065.3
0.304
323.0
742.3
0.0307
12.87
180.
153608.5
12.87
0.622
1065.3
0.305
32469
740.4
0.0307
12.84
181.
154348.P
12.84
0.624
1065.3
0.307
326.9
73P.5
0.0306
12.81
182.
155087.2
12.81
0.625
1065.3
0.309
328.8
736.5
0.0308
12.78
1830
155823.
12.78
0.627
1065.3
0.311
330.8
734.5
0.0308
12.75
184.
156558.1
12.75
0.628
1065.3
0.313
332.P
732.5
0.0308
12.72
185.
157290.6
12.12
0.630
1065.3
0.315
330.8
730.5
0.0308
12.68
186.
158021.0
12.68
0.631
1065.3
0.317
336.8
72.5
0.0308
12.65
187.
158749.4
12.65
0.633
1065.3
0.319
338.9
726.4
0.0306
12.62
188.
159475.8
12.62
0.634
1065.3
0.321
341.0
724.3
0.0308
12.59
189.
160200.1
Subject TRANSPORT RATIO METHOD
12.59
0.636
1065.3
0.323
343.1
722.2
0.0309
12.56
190.
160922.3
12.56
0.638
1065.3
0.324
345.2
720.1
0.0309
12.53
191.
161642.3
12.53
0.635
1065.3
0.326
347.3
110.0
0.0309
12.50
192.
162360.3
12.50
0.641
1065.3
0.329
349.4
715.9
0.0309
12.47
193.
163076.1
12.47
0.642
1065.3
0.331
351.6
713.7
0.0309
12.44
194.
163789.8
12.44
0.614
1065.3
0.333
353.8
711.5
0.0309
12.41
195.
164501.2
12.41
0.646
1065.3
0.335
356.0
705.3
0.0309
12.38
196.
165210.5
12.36
0.647
1065.3
0.337
Date 9/86
358.2
708.1
0.0309
12.35
197.
165917.5
12.35
0.645
1065.3
0.335
360.5
704.8
0.0309
12.31
198.
166622.3
12.31
0.650
1065.3
0.341
36?.7
702.6
0.0309
12.28
199.
167324.9
12.28
0.652
1065.3
0.343
365.0
700.3
0.0309
12.25
200.
168025.1
12.25
0.654
1065.3
0.345
367.3
698.0
0.0309
12.22
201.
168723.1
12.22
0.655
1065.3
0.347
369.6
695.7
0.0309
12.19
202.
169418.7
12.19
0.657
1065.3
0.350
372.0
693.3
0.0309
12.16
203.
170112.0
12.16
0.659
1065.3
0.352
374.3
691.0
0.0309
12.13
204.
170802.9
12.13
0.660
1065.3
0.354
376.1
688.6
0.0309
12.10
205.
171491.4
12.10
0.662
1065.3
0.356
COMPUTATION SHEET
373.1
686.2
0.0309
12.07
206.
172177.5
12.07
0.664
1065.3
0.359
3A1.6
683.1
0.0309
12.04
207.
172861.2
12.04
0.665
1065.3
0.361
384.0
661.3
0.0309
12.01
208.
173542.4
12.01
0.667
1065.3
0.363
386.5
678.8
0.0309
11.98
205.
174221.2
Checked by
11.98
0.669
1065.3
0.366
389.0
676.3
0.0309
11.94
210.
174897.4
11.94
210.
174897.4
Project SHINNECOCK INLET
Date
8 jo 5-23 Page
K.E
10 X to TO THE INCH.7 X 10 INCHES
KEUFFEL & ESSER CO. MADE IN USA
46 0703
M
350
NS
21
42
O
THE
is.p
OVER:38 WE 32
OVER:241038
DV 12) 2.5
N .
:
MEDICINE mit KANGERUPHY RANGE CMPH)
4
LEGEND
!
PART
-
5
i
not NOTICITY ON" ONION
100
ass
ON
-
HJ
4
OF
se
(axyo)
X
80
was
224
MI
10% 1536 20 25
KO YR, AVERAGE (1940-1959) - 1959)
50UT H SHORE OF LONGISLAND
WIND DIAGRAM
E
OKI
by
a
RA
a
11,
20
5
18
S
911
FIGURE C2
52
5/29/89
wind
E
K.E
10 X 10 TO THE INCH. , X to INCHES
46
0703
KEUFFEL B ESSER CO. MADE IN U SA.
JETTY
oit SEM
30
0
OH
20
0
(1)
STA 2-00
x
2019
OOH
REVISED
*
000
X
*
DROSS SECTIONS
COMPARATINE CHANNE
137N EDODENNES
*
*
X
OUP
80 JUMERS C H
JUNE E 84
91 955-56 46
41121
EAST
FIGURE C3-3
1000 A-1
OH
30
oz
01-
01
0
©(FF.ML) e MLW)
K-E
10 X to TO THE INCH X 10 INCHES
KEUFFEL & ESSER CO. MADE IN U.S.A.
46 0703
DELLY
&
09
8
a
Clx-
30
20
01
0
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O
,
.
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STAHTOO
GP
0
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002
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600
CROSS SECTIONS
COMPARATIVE CHANNE
SHINNECOCK INLETT
008
t 89 m on 4
84 JUNE a E
1955-56 19 5 5 - 56
.
0
III 0
70
60
OS
0/01
30
20
0
SHNNECOCK INCE
COMPAR ATIVE CHANNEL
CROSS SECTIONS
STA 6+00
WEST
10
110
Tall
EAST
DENT
H
0
0 +FF(MLW)
46 0703
P
10
10
P
P
20
20
125
X
9
30
30
10 X 10 TO THE INCH. 7 x 10 INCHES
KEUFFEL a ESSER CO. MANT IN USA
X
X
x
-40
in
IP
+
JUNE 84
*
*
*
18 11 11
K.E
$
50
0
e
200
400
600
800
1000 El
PENSEN
SIGURE c3-5
SHINNECOCR INCET
COMPARATIVE CHANNEL
CROSS SECTIONS
STA 8+00
**
WEST
HO
+10
DETTY
THE
JETTY
O
O FT (AILW) e
46 0703
10
40
X
1
-20
.
20
+
x
X
10 X 10 TO THE INCH. 1 X to INCHES
is
30
KEUFFEL a ESSER CO. MADE IN USA
-40
1955 56
10
JUNE or
*
*
A
JUNE 85
K·E
8
50
LO
200
400
600
800
1000 FT
DEVISED
ETGURE c3-b
SHINNECOCK NCE
COMPARATIVE CHANNE
CROSS SECTIONS
STA 10+00
WEST
e
110
JETTY
e
e FT (MLW)
46 0703
10
to
X
20
*
20
©
X
0
Date
10 X 10 TO THE INCH x 10 INCHES
30
o
30
KEUFFEL & ESSER CO. MADE OR USA
x
10
"
10
K.E
955-56
N
4
677
56
to
&
as
in
50
e
200
400
600
800
000 E R
REVISED
FIGURE C3-7
SHINNECOCK INLET
COMPARATIVE CHANNE
CROSS SEC ONS
STA 2+00
110
0
NEW
VETTY
0
OFT.(MLW)
0
46 0703
ID
F
10
.
:-
0
20
20
10 X to TO THE INCH. , X to INCHES
30
30
KEUFFEL & ESSER CO. MADE IN U U.A
X
B
HO
1X
40
K.E
DI
h
£ G in
if
+
41 m
84
50
*
HI
B5
so
9
202
00%
600
800
000
=
K&E
to R 10 TO THE INCH. 7 X to INCHES
KEUFFEL a ESSER CO. MADE 183 U $ 0.1
46'0703
И MILES
-50
-40
oz.
011 isam
OF
of
e
0
00+H #1S
200
x
ooh
REVISED
0.09
#
CROSS SECTIONS
COMPARATIVE CHANNEL
JA7N YDODANNILS
I
008
se 3 N 10
m UNE of
25 4 61 5561
/
a
FIGURE C3-9
1000 FT
PS
or
OE
20
6
01+
(MEW) F 0
.
BEACHES WEST OF
CREAT PROGRES say
ANMY
SITE
SHINNECOCK INLET
ATLANTIC GREAN
LOCATION MAP
SHORELINE
CHANGE MAP
SHINNECOCK
0
BILEY
EASTPORT
WESTRAMPTER
045
-
043
ATL ANTIC OCEAN
LIMITS OF ERODING BEACH
MORICHES MORKINGS any Pino
GROIN
RANGES
FIELD
046
046A
046B
047+1000
047+ 500
047
MM . 0007
-
REVISED
FIGURE C4
SHINNECOCK BAY
046A
E9F6
047
0478
047B
048
DUNE ROAD
LEGEND
1985
1983
1982
1976
SHINNECOCK INLET
1968
LONG MLANG, new vons
1956
400
0
See
ATLANTIC OCEAN
SHORELINE
SCALE 1°:800°
CHANGE MAP
FIGURE
05
REVISED
LEGEND
FLOOD DELTA MHWLINES
4
1956
x
1968
SHINNECOCK
0
1978
BAY
o
1982
1985
SHINNECOCK
LEGEND
INLET
EBB DELTA CONTOURS
DEC. 1955
JUNE 1989
JUNE 1985
1
KNLW
/
BMLW
12
MLW
!
KMLW
50MLW
so
MLW
ATLANTIC RNLW OCEAN
SHINNECOCK INLET GDM
EBB AND FLOOD TIDAL
DELTA MOVEMENT
REVISED
FIGURE C6
(DEPOSIT IN BAY)
20,000 CY/YR.
6000 CY/YR.
(EROSION)
61,000 CY/YR.
(BEACH EROSION)
247,000 CY/YR.
(TRANSPORT OUT)
300,000 CY/YR
100,000 CY/YR.
(TRANSPORT IN)
(DEPOSIT ON BAR
AND DELTA )
SHINNECOCK INLET
SEDIMENT BUDGET
FIGURE C7
6
Ac
Critical
Flow Area
Hydraulically Unstable
Hydraulically Stable
5
Stable Inlet
Conditions
MAXIMUM CURRENT VELOCITY, max' Vmax' (ft/sec)
4
Dewnittong Mode Movement Curve
- security Curre
V Vmax = 2.04
3
Maintenance Criterion
Inlet Closure
Inlet Closure
2
NOTE: This curve represents the typical
shape of the Vₘₐₓ versus Ac
curve. The relationship of the
1
curve to the axes changes from
case to case.
0
1000
5000
10000
50000
CROSS-SECTIONAL FLOW AREA, Ac (ft2)
FIGURE C8
Typical Hydraulic Stability Curve Showing Various Inlet Stability Conditions.
10
9
8
7
600
6
5
4
SHINNECOCK NET
STAB LITY ANALYSIS
1984 EXISTING NG
VMAX=2.04AC
6 8 4 9 $ the
FIGURE C9
3
46 4973
CONDITIONS
&
2
2+
2
-
7 8 9
AREA, Ac Ac (FT2) (FT2)
104
-
SEMI-L SEMI-LOGARITHMIC 02 CYCLES X 20 DIVISIONS
682 $ 8 4 9
6
KEUFFEL a ESSER CO. WADE ($) USA
5
4
956 CONDIT ONS
C
x
4
3
3
K·E
2
N
(Sd3) XVWA
O't
O'C
2.0
My
10
1.
BAY
CHANNEL
N
100
FT.
'200
t
Recommended Channel
Alignment
of
RECOMMENDED
SEDIMENTATION
BASIN
A
OFFSHORE
BAR
/A
SHINNECOCK INLET
NAVIGATION CHANNEL
600 FT.
(- 8.0 MLW
70
TO
I
I
SECTION A-A
RECOMMENDED CHANNEL ALIGNMENT
AND SEDIMENTATION BASIN
FIGURE C10
È
Panglogog
Tisna
1800
the
?
4008
me
sono
NINE 1111
geor.
INVORTISE
0
Boy
CONSUIR INTERVAL 10 FEE:
LINES REPRESENT 4.001 CITITUMS
DATUM IS MEAD SIA HIVEL
DEPTH CURVES MD SOURDING: IN " CATUM is MEAN LOW WATER
- - 8.0mg get APPROVIMOSE " *gam MBH mails
Islands
'⑈8 our BANDE (if BIOS is 0110 GIONG I+1 DEFAN
IN'S
0
0811
West Point
Rempestere
" CUANT BEARD STA
Sand
3rd
Ponquojoe Pl
SOUTHAMPTON
East Point
Area
Inles
Processed Three
Air
Booms
Project
good
TRANSECT 12
TRANSECT
sense
Area to be Dredged
+
Selected
0
Borrow Area Cere Locations
Disposal Area
are
Profile Locations
$8
88
MONITORING LOCATIONS
18
REVISED
FIGURE C11
COMPUTATION SHEET
Page C1-1 of B
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by
Date
Checked by
Date
STABILITY CONSIDERATIONS
1. The stability of Shinnecock Inlet was estimated using the
inlet analytical hydraulic model (Reference 1) based on
principles developed by Keulegan (Reference 2). The model
relates the maximum flow velocity in an inlet to the minimum
cross-sectional area of the channel. Application of the
model to Shinnecock Inlet is contingent upon the assumptions
listed below.
a. The inlet cross-sectional area is uniform over the
length of the inlet,
b. The ocean tide can be represented by a sinusoidal
function,
c. The bay water level rises and falls uniformly,
d. There is no substantial inflow to the bay other than
through the inlet,
e. and the bay area is constant over all tide ranges.
The results obtained are considered meaningful in the
identification of possible inlet trends, and not as a basis
for design.
2. The stability analysis is based on the development of a
stability curve representative of conditions at a particular
inlet. The peak of this curve, which plots a relationship
between inlet minimum cross-sectional area and average
maximumcurrent velocity, is known as the critical cross-
sectional area and is interpreted to be the point of incipi-
ent stability. For minimum cross-sectional areas less than
the critical area the flow is governed by frictional forces.
This results in an inlet unstable to changes in flow area or
maximum velocity. When the flow area is reduced by shoaling,
or if the velocity is reduced by changed flow characteristics
the inlet responds by futher reducing area or velocity until
the inlet closes. Conversely, an unstable inlet which starts
to scour, by either a reduction in sediment supply or an in-
crease in velocity, will continue to scour until the critical
flow area is achieved. For cross-sectional areas greater
than the critical area, the flow through the inlet is
governed by the continuity requirement resulting in an inlet
stable to changes in flow area or velocity. In this condi-
tion, any change in cross-sectional area will cause the inlet
to respond by compensating in such a way as to force its
return toward the equilibrium position. A stable inlet can
close, however, if the velocity does not exceed the mainten-
ance criterion defined as the velocity needed to scour sand
deposits from the inlet channel. This velocity is given by
the equation:
0.05
Vmax = 2.04 Ac
These characteristics are shown on the generalized inlet
hydraulic stability curve of Figure 1.
COMPUTATION SHEET
Page £1-2018 of
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by
Date
Checked by
Date
3. Using all available hydrographic survey, bay and ocean
tide data, and a measured bay area of 4.07 X 10ᵉ ft2, the
stability curves of Figure 2 were developed. The lower curve
in this figure was developed from 1956 hydrographic and tidal
conditions at Shinnecock Inlet. The minimum inlet cross-sect-
ional area of 5500 ft2 , as determined from the Nov/Dec 1955-
Jan 1956 survey, indicates that the inlet was hydraulically
unstable at that point in time. This is due to the fact that
the minimum area plots on the 'scour' side of the stability
curve. The upper curve of Figure 2 was developed from hydo-
graphic survey and tidal data obtained after the Federal
emergency dredging of June 1984. A minimum cross-sectional
area of 16,600 ft2 was determined for the inlet using the
hydrographic survey of 16 June 1984. This area plots well
in the stable range of the 1984 stability curve, indicating
that the inlet is currently in a hydraulically stable cond-
ition.
4. Information presented in earlier sections of this report
supports the conclusion that the inlet is hydraulically
stable at the present time. Figure C1 shows that the tide
range in Shinnecock Bay, immediately inside the inlet, con-
tinually increased from the time the inlet jetties were
constructed in 1952 until about 1964. After 1964 the rate of
increase appears to level off and fluctuate about an approx-
mate tide range of 3.0 ft. This value is consistent with the
2.9 mean ocean tide range reported by NOAA for Shinnecock
Inlet. The tidal prism, defined as the volume of water
entering the bay, is the product of the bay tide range and
effective bay surface area. An increase in bay tide range is
indicative of an increase in tidal prism, which in turn by
hydraulic continuity is proportional to an increase in
convyance through the inlet entrance, provided the volume of
water exchanged at the other entrances is relatively small
and can be neglected. Therefore it is expected that inlet
minimum cross-sectional area data should show similar trends
to those exhibited by tide range data. It appears that bay
tidal data, and consequently inlet cross-sectional areas,
support the conclusion that the inlet is in a stable mode.
References Cited:
1) O'Brien, M.P. and Dean, R.G. (1972) Hydraulics and Sed-
imentary Stability of Coastal Inlets, Proceedings: 13th
Coastal Engineering Conference.
2) Keulegan, G.H., Tidal Flow in Entrances, Water Level
Fluctuations of Basins in Communications with SEAS, Corps
of Engineers, U.S. Army, June 1967.
3) Czerniak, M.T., (Tetra Tech, Inc.) Emgineering and Envir-
onmental Assessment for the Stabilization and Sand Bypassing
of Moriches Inlet, Prepared for NY District Corps of
Engineers, Contract DACW-51-75-C-0015, Jan 1976.
Computed by
6
Ac
Critical
Flow Area
Hydraulically Unstable
Hydraulically Stable
5
Subject STABILITY ANALSIS
Stable Inlet
MAXIMUM CURRENT VELOCITY, V. Vmax' (ft/sec)
max'
Deposition Along Movement Curve
Conditions
4
Date
Down
NOTICE
Upward Curve
Vmax = 2.04 AC.05 c
3
Maintenance Criterion
Inlet Closure
Inlet Closure
COMPUTATION SHEET
2
NOTE: This curve represents the typical
shape of the Vₘₐₓ versus Ac
Checked by
curve. The relationship of the
1
curve to the axes changes from
case to case.
0
1000
5000
10000
50000
Date
Project SHINNECOCK INLET
CROSS-SECTIONAL FLOW AREA, Ac (ft2)
8
FIGURE L Typical Hydraulic Stability Curve Showing Various Inlet Stability Conditions.
PAGECI-40F 8
10
9
$
8
00
7
COO
6
Ф
5
I
4
3
WGTN N XDOD3NNIHS
STAB STABILITY:ANALYSIS $18 ANALYSIS
1984 EXIST STI NC EXISTING
VMAX=2.04Ac
46 4973
CONDITIONS
3
2
2
1
AREA Ac (FT2)
04
9
$
8
03
7
SEMI-L OGARITHMIC 02 CYCLES X 70 DIVISIONS
6
$
KEUFFEL & ESSER CO. MADE IN IN USA
5
4
956 DIT CONDIT ONS
to
3
£
KE
2
N
X
4.0
0
3
3.0
2.0
3
N
0
1.
FIGURE 2
COMPUTATION SHEET
Page C1-50s B
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Date
Checked by
Date
Computed by DMM
STABILITY ANALYSIS USING O'BRIEN AND DEAN METHOD
SQUARE 1 11 THE INCH
REPLETION COEFFICIENT K= T Ac
29 ao
(EQI.)
2TTao AB
Ken + Kex + fl/4R
FOR 15 JUNE '84 (POST EMERGENCY DREDGING) CONDITIONS :
Ac (FROM FIG. 16,600 FT2
ao = 1.45 FT. (NOAA)
RH = 19.72 FT.
ab= 1.30 FT. (TIDE GAGES)
(USING RH = Ac/(W+2D))
T= 12.42 HRS (44,700 SEC.)
AB = 4.07 x108 FT2 (MEASURED)
f = 0.03
Ken + Kex = 1.3 CO'BRIEN + DEAN)
FROM FIG. 4 O'BRIEN + DEAN; USING ab/ao = 0.9, KE= 1.13
RE- ARRANGING EQ. 1:
le = -[ ( 2ПКАВ TAc)2 ao 29 - (Ken+kex)] 4R F
=
-
44700(16,600) (64.4) - 1.3
2π (1.13) 4.07x108 1.45
1
4(19.72)
0.03
le = 4282
USING CONSTANT lE,
K= 44700 Ac
64.4 (1.45)
2π (1.45) 4.07x108
1.3 + (0.03(4282))/4R
K= 1.165*10⁻⁴ 10-4 Ac
.
(EQ.2)
V1.3 + 321/R
VMAX= 2TTao As V'MAX
NANY FORM 229 Apr 70
T Ac
= 8.295 x104 V'MAX
;
(EQ.3)
Ac
P= Zab AB = 290AB (ab/a.) i
(EQ.4) 4)
COMPUTATION SHEET
Page 1-60i8
Subject
STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by DMM
Date
Checked by
Date
15 JUNE 1984, STABILITY CALCULATIONS:
(1)
(2)
SAUARE & 585 TO THE INCM
(3)
(4)
(5)
(6)
Ac(Fr3
RH (FT.)
K
V'MAX
VMAX
QMAX
ab/ao ab 100
P (FT3)
2000
2.48
0.062
-
-
-
-
-
3000
3.72
0.111
0.105
2.90
8700
0.121
1.428 x108
4000
4.94
0.167
0.150
3.11
12440
0.185
2,183 70
5000
6,15
0,228
0.210
3.48
17400
0.255
3.010 x108
6000
7.36
0.294
0.270
3.73
22380
0.335
3,954 708
7000
8.56
0.363
0.330
3.91
27370
0.405
4.780 x108
8000
9.76
0.435
0.385
3.99
31920
0.470
5.550 x108
9000
10.94
0.510
0.445
4.10
36900
0.545
6A33 $808
10000
12.12
0.586
0.500
4.15
41500
0.610
7.200 x108
12000
14.46
0.745
0.610
4.22
50640
0.735
8.675 <108
14000
16.77
0.910
0.690
4.08
57120
0.820
9.678 x108
16000
19.05
1.079
0.760
3.94
63040
0.885
1.045 #109
18000
21.30
1.252
0.815
3.76
67680
0.930
1.09T x10"
20000
2353
1.427
0.865
3.59
71800
0.955
1.127 x10'
25000
29.99
1.892
0.945
3.14
78500
0.985
1163 1.163*10*
30000
34.29
2.337
0.980
2.71
81300
0.990
1.168 5108
35000
39.44
2.804
0.990
2.35
82250
0.995
1.174x109
40000
44.44
3.277
1.0
2.07
82800
1.0
1.1803x109
(1) K FROM (EQ.2)
(2) V' MAX. FROM FIG. 3, O'BRIEN + DEAN
(3) VMAX FROM (EQ3)
(4) QMAX = VMAX xAc
(5) ab/ao FROM FIG. 4, O'BRIEN + DEAN
(6) PFROM (EQ.4)
FOR MAINTENANCE VELOCITY :
NANY FORM 229 Apr 70
VMAY > 2.04 Aco.05
COMPUTATION SHEET
Page C1-7of of 8
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by DMM
Date
Checked by
Date
STABILITY ANALYSIS USING O'BRIEN AND DEAN METHOD :
SQUARE I 511 10 THE INCH
FOR 1955- JAN 1956 CONDITIONS:
Ac= (FROM FIG. ) 5500 FT2
as = 1.4 FT. (NOAA)
RH = 6.76 FT
an = 0.35 FT, (SURVEY REPORT)
(USING RH = Ac/(W+20))
T= 12.42 HRS (44700 SEC)
AB: = 4.07 x108 FT.2 (MEASURED)
f= 0.03
Ken + Kex = 1.3 CO'BRIEN & DEAN)
FROM FIG. 4 O'BRIEN AND DEAN, USING ab/ao = 0.25, KE = 0.22
RE -ARRANGING EQUATION 1:
le = [ 2IT TAC KAB 22% ao - (Ken + Kex) ] 4R f
= ( 2TT 44700 (0.22) (5500) 4.07x10 )2 64.4 1.4 - (1.3) ] 4(6.76) 0.03
lE = 6746 FT.
USING CONSTANT le,
K= T Ac
2g ao
;
(EQ. 1)
2πao AB
Ken+Kex to fle/4R
K= 44700 Ac 64.4(1,4)
2TT(1.4) 4.07*108 1.3+ 50.6/R
K= 1.185 x10-4 Ac
1.3 + 50.6/R
;
(EQ.2)
VMAX= = 80093 V'MAX
Ac
j
(EQ.3)
NANY FORM 220 Apr 79
P= 2ab AB = 2.9.AB (ab/a.)
P = 1.1396x109 (ab/as)
; (EQ.4)
COMPUTATION SHEET
Page C1-8018 of
Subject STABILITY ANALYSIS
Project SHINNECOCK INLET
Computed by DMM
Date
Checked by
Date
1955 - JAN 1956 STABILITY CALCULATIONS
(1)
(2)
(3)
(4)
G
(6)
SQUARE I SES 5 10 THE INCH
Ac (FT)
RH (FT.)
K
Y'MAX
MAX
QMAX
ab/ao
P(FT3)
2000
248
0.051
-
-
-
-
-
3000
3.72
0.092
-
-
-
-
-
4000
4.94
0.139
0.125
2.50
10,000
0.160
1.823 1.823 408 H08
5000
6.15
0.192
0.182
2,92
14,600
0.210
2.393x108
6000
7.36
0.249
0.230
3.07
18,420
0.280
3,191x108 3,191x
7000
8.56
0.309
0,285
3.26
22,820
0.350
3,989,110
8000
9.76
0.372
0.330
3.30
26,400
0.410
4.672.10
9000
10.94
0.438
0.390
3.47
31,230
0,480
5,470 x108
10000
12.12
0.506
0.435
3.48
34,800
0.540
6,154,10ᵗ
12000
14.46
0.649
0.540
3.60
43,200
0.660
7.521x10
14000
16.77
0.798
0.635
3.63
50,820
0.760
8.661x108
16000
19.05
0.953
0.710
3.55
56,800
0.830
9.459 *10
18000
21.30
1.113
0.775
3.45
62,100
0.890
1.014*10
20,000
23.53
1.276
0.830
3.32
66,400
0.930
1.059*109
25000
29.99
1.714
0.920
2.95
73,750
0.975
1.111*10*
30,000
34.29
2.134
0.970
2.59
77,700
0.990
1.128*109
35,000
39.44
2.581
0.990
2.27
79,450
0.995
1.134Y109
40.000
44.44
3.035
0.995
1.99
79,600
1.0
1,1396x109
(1) K FROM (EQ. 2)
(2) V'MAX FROM FIG. 3 ,O'BRIEN + DEAN
(3) VMAX FROM (EQ.3)
(4) GMAX = VMAX x Ac
(5) ab/ao FROM FIG,4, O'BRIEN + DEAN
(6) PFROM (EQ.4)
FOR MAINTENANCE VELOCITY:
NANY FORM 220 Apr 70
VMAX > 2.04 Ac 0,05
(O'BRIEN + DEAN)
COMPUTATION SHEET
Page C2-1 of 1
Subject
Design wave Analysis - West Jetty
Head Section - Existing Design
Project SHINNECOCK INLET
Computed by
Date 9186
Checked by
Date
To determine the maximum wave resisted by existing west
jetty head section equation 7-116 SPM pg.205
will be used as follows:
SOLARE 6X5 TO THE HICH
W- wr H3
Ko(sr-1)3 cot e
where
W = weight in pounds of an individual armor
unit in the primary cover layer.
Maximum size of existing nead armor
units is 12 tons.
wr = unit weight (sat. surf.dry) of armor unit
lbs/f3. - use 165 lbs/f+3
H = maximum design wave height at the
structure in ft.
Sr = specific gravity of anmor, relative to water
at the structure Sr= wr/ww
S. = 165/64.0 = 2.58
ww = unit weight of water, 64.0 lbs / ft
θ = angle of structure slope
cot e = 1.5
KD = stability coefficient, for rough angular
quarry stone head section, on a 1Von 15 H
for a brea Kina wave
use KD= 1.9
substituting
Himan +(24.000)(255-1)*(.5)(1.9 = 1635.1
(165)
Hmax = 11.8 feet
NANY FORM 229 Apr 70
COMPUTATION SHEET
Page C3-1 of 2
Subject Design current Velocity
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
The maximum velocity of tidal currents in mid channel
through a navigation opening can be approximated
= THE ISCRI
by Eg 7-128 pg 7-250, SPM:
V = 4TAh
(7-128)
3TS
where:
N= maximum velocity at center of opening
T = Period of Tide (12.4 hrs s 44,640 sec)
A S Surface area of bay (16mi², 446,054,40059 ft)
5 = Cross- sectional area of opening (16,600 sq. f+)
n a range of tides in bay (ft.)
V= 4 TT (446,054,400) h
3 650) (16,600)
No 2.52h
For the estimated bay tidal range resulting
from a 1938 # vericane (Recurring) of 4.0 feet
(from Fire Island to Montauk BEC of HP Survey Report)
to velocity is given
V= 2.52(4,0)= 10.1 H /see
:-0
10 tps is design current velocity at
jetty head section
NANY FORM 220 Age 10
COMPUTATION SHEET
Page C3-201 2
Subject Design Current Velocity
Project SHINNECOCK INLET
Computed by
Date 9 / 86
Checked by
Date
To estimate a maximum probable design current velocity
at the bay shoreline east of the inlet, the
TO THE INCH
Continuity Equation was uti lized.
Az
SEE
-
9
TZ
ROIMERS
west letty
A,
East Jetty
Q= VA
Q,E Q2 where Q₁ and Q2 are the dis charges at
the cross sections 1 and 2
N,A, = V2 Az
Azi 24,000 ft2
N₂ = V, A1
Az
Substituting in computed maximum probable velocity
at the inlet throat and measured cross-sectional areas
V23 10 fps X 16,600 42 = 6.9 fps
24000 f2
V2/7 = 7.0 ft/sec,
This velocity will not however control the revetment
7
design. The revetment design is controlled by wind
generated bay waves shown in computation C5
The D/. revetment design is detailed in Computation
61 sing 628 WMOd ANVN
COMPUTATION SHEET
of 4
DESIGN WAVE ANALYSIS
Subject
Project Shinnewck Inlet GDM
WEST / EAST JETTY HEAD SECT
Computed by
Date 9/86
Checked by
Date
TO THE HICK
1 The wave climatology selected for use in this
study was available by the U.S. Army Corps
515
"Atlantic Coast Hindcast, Shallow Water Significant
Waterways Expenment Stahm and titled
Wave Information" (Ref 10). The tables used
squar
were for station # 46. See Tables C-4.1 $ C-4.2
2. Retraction and Shoaling COR tficients were estimated
using a simplified method CRef. 26 I Thotallowing
assumption are implicit in this approach
a. effects of currents are precluded
b. wave ware interaction 19 prestuded
6 effects of wave energy reflection onstructs preclude
d. attenuation by frection precluded
e. assume straight and 11 contones
DIRECTION OF SIGNIF ! WAVE 11 REFRACTION REFRACT
WAVE APPROACH
WAVEHGT
PERIOD SHOALING SHOALED
@30'deptz
(sec)
COFF
WAVE HGI
(FT)
KR As
KET)
@
2
3
D
30°-59.9" If
30° 20' 30' 20'
(187°-217°) 21
12.5
9.5
0.85 0.89 10.6 VI.I
[45°] 31
60°-899
14.2
11
1.06 1.12 15 15.9
(157-187)
[150]
90° -119.9°
14.2
11
1.06 1.12 15 15.9
(127°-157°)
[15°]
120° - 1499°
10.8
9.5
0.25 0.89 9.2 9.6
NANY FORM 220 Age 70
97-127°
[45]
COMPUTATION SHEET
pagk4-201. Pagé 4
DESIGN WAVE HEIGHT
Subject
WEST LEAST JENY HEAD SECT
Project Shinnecock Inlet GDM
Computed by
Date 9/86
Checked by
Date
WAVE MAXIMUM HEIGHT TABLE (CONT'D):
DIRECTION OF
SIGNIFICANT
WAVE
KR.Ks
REFRACTED!
TO THE MICH
WAVE APPROACH
WAVE HGT. 0 PERIOD
SHOALED
30' depth
WAVE HGT
CFT)
(sec)
so
(FT)
115
$0'20'
@20' @30
150-179
7.5
6.5
0.60.55
4.5 3.6
SSUARE
(67°-97°)
[75°]
:. Maximum Wave Height Expected = 16 ft.
NOTES:
11 Wave direction, height and period obtained
from WIS tables C-41 C-4,2
21 Wave direction. converted to true north
compass aszimuth using
(1270) 20 (157°) 90 (1870)
WIS
60
arbitrary angle classification
(970) 150
30 (217)
WIS angle classification
converted to true
(670) 180
(2470)
north aszmuti
Mr.
Shoreline orientation
N
B/ average of WIS wave angle section measured
from the shore normal for use in
refraction analysis Ret26,
NANY FORM 220 Apr 70
41 Refraction and shooling coefficient KRiks
obtain from Ref. 26
COMPUTATION SHEET
Page C4-3 of 4
DESIGN WAVE ANALYSIS-
Subject
Project
WEST JETTY HEAD SECTION
Computed by
Date 9 /86
Checked by
Date
The design wave which allows for the full impact of
a breaking wave upon the structure (see Chap 7 Section 7.a.
THE
Da. 7-202 SPM) 5 : and is limited by the depth
of water above the existing be Hom (H=0.78 d, Eg 2-91,
pg 2-130, SPM) is computed assuming 0 non-linear
111
surface profile as shown below.
SOURT
el + 9MLW
I
ash
SWL
nemall
102H
MLW
d
WEST JETTY HEAD
SECTION
L
EXISTING BOTTOM
PROPOSED BASIN
CUT
TRY SWL = +8 FT MLW
Depth at tar (ds) = 8 + 14 = 22ft.
Defth limited wave height = O. 78/22° 17.16 ft
Depth of trough below SWL = 0.2 117.16)= 3.43H
elevation of trough = +8 Mid, - 3A = 4.6 Ft MLW
Full Impact is Not Achieved
IMPROVED
+4,6 H MLW < if 9.0 H MLW
Full
Depth limited
Depth of trough
Elevationot
Impact
SWL
do
wave height
below SWL
trough
Achieved
&
8.0 MLW
22
17.16
3,43
4.6
NO
+
0.0
24
18.7
3.7
6.3
NO
+
12.0
26
20.3
4.1
7.9
NO
+
13.0
27
21%
4.2
8,78
NO
+
14.0
28
21,8
4,4
9.6
No
:00 Full IMPACT 15 achieved For
design $ WL between #13 MLW and +14MLW
NANY FORM 220 Age 10
TRY SWL =+13.2
13.2
27.2
242
4.24
8.95
YES
Depth Limited Wave Height
=21.2H.
(Improved Condition)
COMPUTATION SHEET
Pag Pas.C4-4 of 4
Subject DESIGN WAVE ANALYSIS
WEST LEAST JENY HEAD
Project shinnecock Inlet 60m
Computed by
Date 9/86
Checked by
Date
SQUARE X SES THE MICH
EXISTING CONDITION Waves Breaking on Existing Bar
SWL
ds
Depth limited Depth trough EL of Full Insport
have Height below SWL Trough Achieved
+8,0 MLW 16'
12.5'
2.5'
+5.5 mcm NO
710,0
18'
14.0'
2.8'
+7.2MW No
T12.0
20'
15.6'
3.1'
+8,9 Mcu VES
12.5
20.5'
16.0'
3,2'
+9.3mcm NO
: Full IMPACT KS ACHIEVED FIR EXISTING COND.
SWL = T12 Ft MCW
DEPTH LIMITED WAVE HEIGHT a 15.6FT
(EXISTING CONDITION)
Design wave Height for Jetty Head Section = 16 ft.
Based on N.I.S. Hindcast
and Refraction- Shallowing Analysis.
NANY FORM 220 Apr 70
COMPUTATION SHEET
Page C5-/of /
Subject Design Wave Height for
Proposed Revetment
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
To stabilize the bayside of the dune and prevent
material losses, a revetment was designed using
= = THE NOM
Corps criteria. Although the shoreline in the vicinity
of the proposed revetment is sheltered from the
ocean waves it is not sheltered from waves
generated within the bay Using the procedures
published in the SPM and ETL 1110-2-211 for
generation of shallow water waves,e breaking wave
was computed.
Estimated bay depth = -80ft. MLW
Surge +Tide level
+7.3 ft MLW
= 14,500 ft
(+6.Oft NGVD)
Fetch length
Wind velocity VA = 79 mph
using procedures in
ETL 1110-2-221
h
H
T
Figure
(water depth) (wave height) (wave period) (SPM
15
3.3
32
3-29
Assume wave height = 3.3 ft
wave period = 3.2 sec
NANY FORM 220 Age 70
COMPUTATION SHEET
PageCol of 1
Subject CHANNEL WIDTH DESIGN
Project SHINNECOCK INLET
Computed by LMK
Date 9/86
Checked by
Date
The width of the navigation channel at Shinnecock
Inlet was determined by the procedure given in
= THE
EM 1110-2-1615 Hydraulic Design of Small Boat Harbors.
Two design vessels one fishing yessel and one recreational
vessel, were chosen for the two-way traffic.
The beam width of the design recreational vessel is 15 ft.,
and the beam width of the design commercial vessel
is 22 ft. Allowances for outriggers used by the
commercial fishing vessels was included in the channel
width.
CHANNEL WIDTH (VESSELS WITH VERY GOOD MANEUVERABILITY)
BANK CLEARANCE LANE (COMMERCIAL) 150 90x 22' = 33 ft. *
MANEUVERING LANE (COMMERCIAL)
160% X 22' = 35 ft.
70 ft. for Outriggers
= 70 ft
SHIP aEARANCE LANE (COMMERCIAL) 80% X 22'= 18 ft.
MANEUVERING LANE (RECREATIONAL)
160% X 15'= = 24 ft.
BANK CLEARANCE (RECREATIONAL) 150% X 15' - 23 ft.
203 ft.
The Design Channel Width will be 200 ft.
*
Bank Clearance as Per Cent of the Vessel beam were increased
due to existance of the rubble mound jetties and the
ad verse weather conditions.
MANY FORM 220 Apr 19
COMPUTATION SHEET
Page C7-1 of 8
Subject
Shoaling Analysis for a Channet Basin Cut
Through An offshore Bar-Tramport Ratio
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
$205 = I
TRANSPORT RATIO METHOD
FOR
SHOALING OF A DREDGED CUT
THROUGH THE BAR SEAWARD OF AN INLET
-
This method was developed by Dr. Cyril Galvin, under contract
DACW51-79-C-0046 for the New York District, specifically with
reference to Moriches Inlet.
Assumptions. This is an analysis of the shoaling likely to
occur in a cut through a typical ocean bar around the mouth of an
inlet. The analysis depends on the following assumptions:
1. Sand is set in motion by the shoaling and breaking of waves.
2. Once set in motion, the sand is transported by whatever net
currents exist at the site. For the dredged channel, these currents
are assumed to be mostly due to the ebb flow of the tidal prism
coming out of the inlet.
3. Wave motion is adequately described by linear theory.
4. Sediment motion depends on the bottom shear which is
primarily due to the bottom water motion under shoaling and breaking
waves.
General Equation. The purpose of this analysis is to compare
the sediment transport potential in the dredged cut with the
sediment transport on the bar before dredging. The general equation
relates sediment transport to the bottom shear which initiates
sediment motion and the ambient current which moves the sediment
whose motion has been initiated.
Sediment Transport Rate - Coefficient X Bottom Shear X
Ambient Current (1)
Since this analysis compares two conditions in the same
environment, it is assumed that the coefficients for pre and post
dredging conditions are the same. Thus, the ratio of post dredging
to pre-dredging sediment transport is:
Transport ratio = Bottom Shear Ratio X Ambient Current Ratio (2)
MMNY FORM 220 Apr 19
Bottom Shear Ratio. Shear is proportional to the bottom
velocity squared.
:
2
T= constant x U
(3)
-
COMPUTATION SHEET
Page 67-2 of 8
Subject Transport Ratio Method
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
The bottom water velocity under linear waves is sinusoidal, and the
peak velocity, U, will be used to represent this bottom velocity. In
shallow water, for linear theory,
SHIMM 1 515 10 THE
U²⁻= gH²/(4d)
(4)
If we use a subscript 1 to indicate the condition before dredging and
subscript 2 to indicate the condition after dredging, then the bottom
shear ratio is
T2
t2-U2
(4)
T1
=
(5)
From conservation of energy flux for linear waves in shallow water,
H2
(6)
So the bottom shear ratio turns out to depend entirely on the ratio
of pre to post dredging depths.
T2 (d)
(7)
Ambient Current Ratio. The general equation (1) is blind to
whatever causes the ambient current on the bar and dredged cut. For
the case of the dredged cut in the bar opposite an inlet, it is
assumed that the dominant current is due to the ebb tide. The
general relation for the current velocity is
V = Q/A
(8)
where Q is the discharge and A is the channel area. For the
two-dimensional unit channel, A equals depth times 1 foot. So the
ambient current ratio is,
=
(9)
MANY FORM 228 Apr 19
assuming that the discharge will remain the same after dredging and
the ambient current ratio is
V2
=
(10)
COMPUTATION SHEET
Page C7-3 of 8
Subject Transport Ratio Method
Project SHINNE COCK INLET
Computed by
Date 9/86
Checked by
Date
Transport Ratio. It is now possible to combine the bottom shear
S 3008 100%
ratio with the ambient current ratio to get the transport ratio, post
dredging (10), to pre dredging conditions. For the case where Q, R O₂ in
Transport Ratio = (d,/d₂) 5/2
$ 8 %
(11)
to
5
MSL
SEIMM
di
d₂
Natural Bottom Bottom
Botom Basin of Dredged
This ratio may be interpreted as follows, where d and d are
defined by the above figure The table evaluates equation (11) for
given values of d₁/d₂, the ratio of pre to post dredging depth,
measured from Mean Sea Level.
d,
Transport
Ratio
at
0.25
0.031
0.5
0.18
0.7
0.41
0.8
0.57
0.9
0.77
0.95
0.88
The transport ratio is a measure of potential for transporting
sediment in the cut after dredging, relative to sediment transport
before dredging. For example, if the ratio is 1.0, then as much sand
will be taken away by the tidal flow as is brought to the channel.
However, as can be seen from equation (11), the only time the
transport ratio will be 1.0, equation is when d,= d2, that is, the
channel is not deepened at all.
8
If the dredged depth is double the natural depth, d /d2equals
0.5, then the table indicates the transport ratio is 0.18, or roughly
the potential to transport out one cubic yard for every 6 cubic yards
NANY FORM 220 Apt 19
carried in from the sides of the channel (which are assumed to remain
at pre dredging depth, ai).
NANY FORM 220 Age 79
SUGARE
BES
TO THE INCH
The following is an example calculation for 9 500 ft wde deposition basin.
The natural depth of the shoal is 8.0
d
MUW
channel design depth
is 12.0
$
M&W
Computed by
drodge depth
IS - 18.0
4
MLW
Gross Longshore Trans port Volume 400,000 cy /4r
Tranport By: Passing the Inlet Below 18.0 Ft MLW E 2.8 %
Si
SHOULING COMPUTATION FCR 1986
FOR A
908. FOOT WIDE BASIA
TRANSPORT RATIC METHOD
Date
Subject TRANSPORT RATIO METHOP
INFLGW
CUT OF CHANNELCHANNEL
CHANNEL
NEW
CUMULATIVE
DEPTH
TRANSPORT
TRANSPORT
TRANSPORT
SHOAL
DEPTH
CHANNEL
VOLUME
CFPTH
RATIC
VOLUME
RATIO
VOLUME
VOLUME
SHOALED
DEPTH
DAY
SHOALED
EFT.MLWD
(CU.TOS./DAY)
YDS.)
(FT./DAY)
BET.MLW
(CU.YDS.)
18.00
0.045
1065.3
0.132
140.3
925.0
0.0263
17.98
1.
925.0
9186
17.98
0.446
1065.3
0.133
140.9
924.5
0.0264
17.95
2.
1049.4
17.45
0.446
1055.3
0.133
141.4
924.0
0.0264
17.93
3.
2773.3
17.93
0.447
1065.3
0.134
14109
923.4
0.0264
17.90
"
3696.7
17.00
0.44P
1065.3
0.134
142.4
922.9
0.0264
17.87
5.
4619.5
17.87
0.000
1065.3
0.135
142.9
922.4
0.0265
17.05
6.
5541.9
17.45
0.445
1065.3
0.135
843.5
921.9
0.0265
17.82
7.
6463.7
17.82
0.450
1065.3
0.136
144.0
921.3
0.0265
17.79
:
7385.0
17.79
COMPUTATION SHEET
0.450
1065.3
0.136
844.5
920.0
0.0265
17.77
90
0305.7
17.77
0.451
1065.3
0.137
145.1
920.2
0.0265
17.74
10.
9225.9
17.74
0.452
1065.3
0.137
143.6
919.1
0.0266
11.71
11.
10145.5
17.71
0.452
1065.3
0.138
146.1
919.2
0.0266
17.69
12.
11064.6
17.69
0.453
1065.3
0.13*
145.8
918.6
Checked by
0.0266
17.66
13.
11983.2
17.66
0.454
1065.3
0.139
147.2
918.1
0.0266
17.63
10.
12901.2
17.63
0.459
1065.3
0.139
147.
917.5
0.0267
17.61
15.
13618.7
17.61
0.455
1065.3
0.140
199.9
916.9
0.0267
17.36
16.
14735.6
17.58
0.456
1065.3
0.140
10809
916.4
0.0267
17.56
17.
15651.9
17.56
0.056
1065.3
0.141
149.5
915.0
0.0267
17.53
1P.
16567.7
17.53
0.958
1065.3
0.141
150.1
915.2
0.0268
17.50
19.
17482.9
17.30
0.45P
1065.3
0.142
159.6
914.7
0.0268
17.47
20.
18397.5
17.48
0.45"
1065.3
0.142
151.2
914.1
0.0268
17.45
21.
19311.5
17.45
0.459
1065.3
0.143
151.
913.5
0.0268
17.42
22.
20225.0
17.42
0.460
1065.3
0.143
152.0
912.9
0.026P
17.39
23.
Project SHINNECOCK INLET
21137.9
17.39
0.961
1065.3
0.144
153.0
912.3
0.0269
17.37
24.
22050.2
17.37
0.961
1065.3
0.145
153.6
911.8
0.0269
17.34
25.
22961.9
Date
17.34
0.462
1065.3
0.145
150.1
911.2
0.0269
17.31
26.
23873.0
17.31
0.463
1065.3
0.146
154.7
910.6
0.0269
17.29
27.
24783.5
17.29
0.463
1065.3
0.146
155.3
910.0
0.0270
17.26
28.
25693.4
87.26
0.464
1069.3
0.147
156.0
909.4
0.0270
17.23
29.
26602.7
of 8
COMPUTATION SHEET
Page C7-5 of 8
Subject TRANS PORT RATIO METHOD
Project SHINNECOCK INLET
Computed by
Date
9/86
Checked by
Date
= I
CUMULATIVE
VOLUME
SHOALED
(CU.Y03.)
27511.4
28419.5
29326.9
30233.8
32049.6
32950.5
33654.8
34758.5
35661.5
36563.9
37065.6
38366.6
39267.0
40166.0
41065.0
41964.2
42861.9
43758.9
44655.2
45558.8
46445.7
47339.9
40233.4
49126.2
50018.3
50909.7
31800.3
32690.2
53579.3
54967.7
55359.4
56242.3
57128.4
58013.0
4'06885
59702.2
60669.3
61547.5
62429.0
63309.7
64189.5
65068.6
65946.9
66824.3
6°00119
68576.7
69451.6
78325.7
71198.9
72071.3
115
JURIOR
DAY
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
49.
45.
46.
.
48.
49.
30.
51.
52.
53.
500
55.
56.
57.
50.
59.
60.
68.
62.
63.
64.
69.
"6.
67.
6P.
69.
70.
71.
72.
73.
74.
75.
76.
77.
7@.
79.
80.
NEW
CHANNEL
DEPTH
CFT.FLU)
17.21
17.18
17.15
17.13
17.10
17.07
17.04
18.02
16.99
16.96
16.94
16.91
16.09
16.05
16.03
16.40
16.77
16.74
16.12
16.69
16.66
16.63
16.61
16.58
16.55
16.52
16.50
86.47
16.99
16.41
16.39
16.36
16.33
16.38
16.27
16.25
16.22
16.19
16.16
16.14
16.11
16.00
16.05
16.02
15.99
15.97
15.94
15.91
15.00
15.85
15.83
CHANNEL
DEPTH
SHOALED
EFT./DAY)
0.0270
0.0270
0.0271
0.0271
8.0278
0.0271
0.0272
0.0272
€.0272
0.0272
0.0273
0.0273
0.0273
0.0273
0.0274
0.0270
0.0274
0.0284
0.0275
0.0275
0.0275
0.0275
0.0276
0.0276
0.0276
0.0276
0.0277
0.0277
8.0277
0.0277
0.0278
8.0276
0.027h
0.0278
0.0279
0.0279
0.0219
0.0280
0.0280
0.0280
0.0280
0.0281
0.0261
0.0261
0.0281
0.0262
0.0282
0.0262
0.0282
0.0203
0.02A3
VDS.D
SHOAL
90A.7
908.8
907.5
6°905
905.6
SHC 106 COMPUT TICK FOR 1986
905.0
60006
50307
903.1
EUR,OF CHANNELCHANNEL
VOLUME
906.3
902.4
901.8
901.1
900.4
899.8
8'668
898.4
891.1
897.1
896.4
895.7
895.0
894.3
893.6
A92.8
892.1
891.4
890.7
989.9
809.2
@08.5
687.1
6'9RU
8A6.2
885.4
884.7
883.9
8A3.1
882.3
19105
AMO.7
87909
879.1
878.3
877.5
876.7
875.8
A75.0
@70.1
67303
@72.9
TRANSPORT
VOLUME
156.R
157.2
157.8
15*.4
159.0
159.7
160.3
160.9
161.6
162.2
862.9
163.5
164.2
164.9
165.9
166.2
166.9
167.6
169.3
160.9
169.6
170.3
171.0
171.8
172.5
173.2
87309
174.6
175.4
176.1
176.9
111.6
170.0
189.1
179.9
8A0.6
19104
102.2
183.0
193.0
149.6
ing.,
1*6.2
197.0
187.9
180.7
199.5
190.3
191.2
152.0
192.9
500. FOOT WICE 28516
TRANSPORT RATIC METHOD
TRANSPORT
RATIC
0.141
0.148
0.149
0.149
0.100
0.150
0.198
0.152
0.152
0.153
0.153
0.154
0.155
0.155
0.156
0.156
0.157
0.158
0.152
0.159
0.160
0.160
0.161
0.162
8.162
0.163
8,164
0.164
8.265
0.1€
0.186
0.168
0.16R
0.169
0.169
8
8.171
0.172
0.172
0.173
8.174
0.174
0.179
0.176
0.187
0.178
0
8.229
0.888
8.182
INFLOW
TRANSPORT
VOLUPE
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
106503
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
FOR A
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
SI
CONTINUED
DEATH
RATIC
0.465
0.466
0.46E
0.467
0.468
0.469
0.969
0.470
0.471
0.472
9.972
0.473
0.474
0.475
0.475
0.476
0.477
0.478
0.470
0.479
0.488
0.481
0.402
0.482
0.483
0.484
0.485
8.006
0.9MG
0.4dl
8.480
0.489
8.998
0.991
0.491
0.492
0.493
0.494
0.495
0.496
0.496
0.497
0.498
0.499
0.500
0.501
0.502
COS'O
506°0
605°8
606°0
FORM 220 Am 70
DEPTH
(FI.MLW)
17.23
17.21
17.18
17.15
17.13
17.10
17.07
17.04
17.02
16.99
16.96
16.94
16.91
16.88
16.65
16.03
16.00
16.77
16.74
16.72
16.69
16.66
16.63
16.06
16.50
16.55
16.52
16.50
16.47
16.44
16.48
16.39
16.36
16.33
16.30
16.27
16.25
16.22
16.19
16.16
16.14
16.11
16.08
16.05
16.02
15.99
15.97
15.94
15.91
85.88
15.85
COMPUTATION SHEET
Page C76 of 8
Subject TRANSPORT RATIO METHOD
Project SHINNECOCK INLET
Computed by
Date 9/86
Checked by
Date
= a ME
CUMULATIVE
VOLUME
SHOALED
(CU.YDS.)
72942.8
73813.5
74683.3
75552.2
76420.2
77287.3
7815555
79018.8
79883.2
80746.7
81609.3
82470.9
83331.6
84191.3
85050.1
85907.9
86764.7
87620.6
88475.5
89329.4
90182.3
91034.2
91885.0
92734.9
93583.7
94431.5
95278.3
96123.9
96968.6
97812.1
98654.6
59496.0
100336.3
101175.5
102013.6
102850.5
103686.4
104521.1
105354.6
106107.0
107018.2
107848.3
100677.2
109504.8
110331.3
111156.6
9°061111
112003.4
113625.0
&
DAY
81.
82.
83.
84.
85.
26.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
"
"
100.
101.
102.
103.
100.
105.
106.
107.
908
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
129.
126.
127.
124.
129.
130.
NEW
CHANNEL
DEPTH
@FT.MLWD
15.00
15.77
15.74
15.71
15.68
15.66
15.63
15.60
15.57
15.54
15.51
15.4A
15.46
15.43
15.40
15.37
15.34
15.31
15.28
15.26
15.23
15.20
15.17
15.14
15.11
15.08
15.05
15.02
14.99
14.97
14.94
14.91
14.80
14.85
14.82
14.79
14.76
14.73
14.70
14.67
14.64
14.62
19.59
14.96
14.50
14.47
14.44
14041
14.38
CGANNEL
DEPTH
SHOALED
EFT./DAY
0.0283
8.0264
0.0284
0.0284
0.0284
8.0285
0.0265
0.0285
0.0285
0.0286
0.02M6
0.0246
0.0266
0.0287
0.0287
0.02a7
0.0288
0.0268
0.028A
0.0288
0.0289
0.0289
0.0289
0.0289
0.0290
0.0290
0.0290
0.0291
0.0291
0.0291
0.0291
0.0292
0.0292
0.0292
0.0292
0.0293
0.0293
0.0293
0.0294
0.0294
0.0294
0.0294
0.0295
0.0295
0.0295
0.0295
0.0296
0.0296
9670'0
0.0296
0
SHCALING COMPUTATION FOR 1986
CUT OF CHANNELCHANNEL
SHCAL
VOLUME
CU. YDS.)
9'14"
670.7
869.8
0°698
66H.1
867.2
P66.3
865.4
864.4
863.5
862.6
861.7
860.7
859.8
858.8
857.9
6'959
855.9
854.9
853.9
852.9
851.5
6°058
849.9
848.9
647.8
846.8
245.7
849.7
843.6
F42.5
841.4
640.3
839.2
838.1
@37.0
@35.9
834.7
9'E60
832.4
631.3
1*05*
P2H09
627.7
826.5
825.3
#24.1
822.9
821.6
020.4
TRANSPORT
VOLUME
193.7
194.6
155.5
155.4
197.2
194.1
199.0
199.9
200.9
201.0
202.7
203.6
204.6
205.5
206.5
297.4
208.4
209.4
210.4
211.4
212.4
213.4
214.4
215.4
216.4
217.3
214.5
219.6
220.6
22107
222.0
223.9
225.0
226.1
221.2
228.3
229.4
230.6
231.7
232.9
234.8
235.2
23604
237.6
234.8
240.0
241.2
242.5
243.7
244.9
508. FOOT WIGE EASIA
TRANSPORT RATIC METHOD
TRANSPORT
RATIC
0.102
8.183
0.184
0.185
0.186
088°0
0.147
0.180
0.189
06%*8
0.192
0.193
0.193
8
0.195
0.196
0.197
8.198
0.199
0.200
0.201
0.202
0.203
0.204
0.205
0.206
0.207
0.200
0.209
8.210
0.211
0.212
0.213
0.214
0.215
0.216
0.217
0.218
0.219
0.220
0.221
0.222
0.223
0.225
8.226
0.227
0.222
0.229
9.230
INFLOW
FOR A
THANSPORT
BOLUPE
(CU.YOS./DAY)
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
1065.3
SI
CONTINUED
DEPTH
RATIC
905°0
2050
0.508
0.509
01510
0.511
0.512
0.513
0.514
0.514
01516
0.516
0.517
0.918
0.519
0.520
0.521
0.522
0.523
0.524
0.525
0.526
0.527
0.528
0.529
0.538
0.531
0.532
0.533
0.534
0.535
0.536
0.537
0.938
0.539
0.540
0.542
0.543
0.544
0.545
0.546
0.547
0.548
0.549
0560
0.551
0.553
456'8
55500
0.596
MANY FORM 220 Age 70
DEPTH
(FT.MLW)
15.83
15.80
15.77
15.74
15.71
15.66
15.66
15.63
15.60
15.57
15.54
15.51
15.48
15.46
15.43
15.40
15.37
15.34
15.31
15.28
15.26
15.23
15.20
15.17
15.14
15.11
15.08
15.05
15.02
14.99
14.57
14.94
19.91
14.88
14.85
14.82
14.79
14.76
14.73
19.70
14.67
14064
14.62
14.59
14.56
14.53
05.00
10.47
14.41
MMV PORM 220 Apr 70
smart
684
TO 1993 INST
SI
SHCALING COMPUTATION FOR 1986
FOR a
300. FOOT WICE BASIN
TRANSPORT RATIC METHCD
CONTINUED
INFLGO
Computed by
CUP OF CHANNELCHANNEL
CHANNEL
NEW
DEPTH
TRANSPORT
TRANSP CRT
CUMULATIVE
TRANSPORT
SHOAL
DEPTH
DEPTH
CHANNEL
RATEC
VULUME
RATIC
VOLUME
WOLUME
VOLUME
SHOALED
DEPTH
(FT.MIN)
DAY
(CU.YOS.FOAT)
SHOALED
YOS.I
(FT./DAY)
OFT.MLW
ECU.VDS.)
14.38
0.557
1065.3
0.232
246.2
819.1
0.0297
14.35
14.35
131.
0.550
115264.3
1065.3
0.233
207.5
817.8
0.0297
14.32
132.
14.32
0.559
1065.3
116082.1
0.234
24808
216.5
0.0297
14.29
14.29
133.
0.561
116898.6
1065.3
0.235
250.1
@15.2
0.0297
14.26
14.26
134.
0.562
117713.8
1065.3
0.236
251.4
813.9
0.0298
14.23
14.21
135.
0.563
118527.7
1065.3
0.238
252.7
#12.6
0.0298
14.20
136.
14.20
0.564
119340.3
1065.3
0.239
259.0
811.3
0.0298
14.17
14.17
137.
0.565
120151.5
1065.3
0.240
255.3
610.0
0.0298
14.14
14.14
138.
0.566
120961.4
1065.3
0.241
256.1
80H.6
0.0299
14.11
14.11
139.
0.568
121770.0
1065.3
0.243
258.0
807.3
0.0299
14.08
140.
Subject TRANSPORT RATIO METHOD
19.08
122577.2
0.569
1065.3
0.244
257.4
805.9
0.0299
14.05
14.05
141.
123303.1
0.370
1065.3
0.245
260.8
804.5
0.0299
14.02
842.
14.02
0.571
124187.5
1065.3
0.247
262.2
203.1
0.0300
13.99
143.
13.99
124990.6
0.572
1065.3
0.242
263.6
801.7
0.0300
13.96
144.
13.96
125792.3
0.984
1065.3
0.249
265.0
800.3
0.0300
13.93
145.
13.93
0.575
126592.5
1065.3
0.251
266.4
798.9
0.0300
13.90
13.90
146.
8.976
127391.3
1065.3
0.252
267.9
797.4
0.0301
13.87
147.
Date 9/86
130M7
124188.F
0.977
1065.3
0.253
269.3
796.0
0.0301
13.84
148.
13.84
128980.6
0.579
1065.3
0.255
270.4
794.5
0.0301
13.81
149.
129779.1
13.01
0.500
1065.3
0.256
272.3
793.0
0.0301
13.78
150.
13.78
130572.1
0.981
1065.3
0.257
273.4
701.6
0.0302
13.75
151.
13.75
0.582
131363.6
1065.3
0.255
215.3
190.0
0.0302
13.72
152.
13.72
132153.6
0.544
1065.3
0.260
216.9
78A.5
0.0302
13.69
153.
13.69
0.905
132942.1
1065.3
0.262
279.3
787.0
0.0302
13.66
154.
13.66
133729.0
0.586
1065.3
0.263
279.8
785.5
0.0303
13.63
155.
134510.0
13.63
0.598
1065.3
0.265
201.4
783.9
0.0303
13.60
156.
135298.3
COMPUTATION SHEET
13.60
0.569
1065.3
0.266
283.0
782.3
0.0303
13.57
157.
13.57
136080.6
0.590
1065.3
0.262
2F4.5
780.8
0.0303
13.54
158.
13.54
136661.3
0.992
1065.3
0.265
286.1
774.2
0.0303
13.51
159.
13.51
0.593
137648.4
1065.3
0.271
287.7
111.6
0.0304
13.48
160.
Checked by
13.48
0.54
1065.3
135419.0
0.272
209.4
775.9
0.0304
13.45
161.
13.45
139193.9
0.596
1065.3
0.274
291.0
774.3
0.0304
13.42
162.
13.42
1065.3
139968.1
0.097
0.275
292.6
172.8
0.0304
13.39
163.
13.34
0.598
1065.3
140748.7
0.277
294.3
171.0
0.0304
13.36
164.
13.36
0.600
1065.3
141511.7
0.276
296.0
769.3
0.0305
13.33
165.
142281.0
13.33
0.601
1065.3
0.280
297.7
767.6
0.0305
13.30
166.
13.30
143048.5
0.602
1065.3
0.282
294.4
765.9
0.0305
13.27
167.
13.27
103014.0
0.604
1065.3
0.283
301.1
764.2
0.0305
13.24
168.
13.24
144578.6
0.605
1065.3
0.285
302.8
762.5
0.0305
13.21
169.
13.21
105341.0
0.607
1065.3
0.286
304.6
760.7
0.0306
13.18
Project SHINNECOCK INLET
170.
13.1A
146101.6
0.608
1065.3
0.288
306.4
750.9
0.0306
13.14
171.
13.14
146860.5
0.609
1065.3
0.290
308.1
157.2
0.0306
13.11
172.
13.11
0.611
1065.3
147617.7
0.291
309.9
755.4
0.0306
13.08
Date
173.
13.08
148373.0
0.612
1065.3
0.293
311.9
753.6
0.0306
13.05
174.
13.05
149126.5
0.614
1065.3
0.295
313.6
751.7
0.0307
13.02
175.
13.02
149878.1
0.615
1065.3
0.291
315.4
749.9
0.0307
12.99
176.
12.99
150620.0
0.617
1065.3
0.298
317.3.
746.C
0.0307
12.96
177.
151375.9
Page C7-7 of 8
12.56
0.61@
1065.3
0.300
319.2
746.1
0.0307
12.93
178.
12.93
152122.0
0.619
1065.3
8.302
323.1
744.2
0.0307
12.90
175.
192866.2
NANY FORM 229 Age 79
BANK
0
10 IN INTO
SE
SHCALING COMPUTATION FOR 1986
FOR
A
500. FOOT WICE HASIA
THANSPORT RATIC METHOD
CONTINUED
Computed by
INFLOW
CUT OF CHANNELCHANNEL
CHANNEL
NEW
DEPTH
CUMULATIVE
TRANSPORT
TRANSPORT
TRANSPORT
SHOAL
DEPTH
CHANNEL
DEPTH
VOLUME
RATIS
VOLUME
RATIC
VOLUME
VOLUME
SHOALED
DEPTH
DAY
EFT.MLWD
SHOALED
ECU.VDS./OAV)
YDS.)
EFT./DAY8
(FT.MLW)
(CU.VDS.)
12.90
0.621
1065.3
0.304
323.0
742.3
0.0307
12.07
180.
12.87
153600.5
0.622
1065.3
0.305
324.9
740.4
0.0307
12.84
12.04
181.
154348.8
0.624
1065.3
0.307
326.9
73P.5
0.0306
12.81
12.81
182.
155087.2
0.625
1065.3
0.309
32*.8
736.5
0.0308
12.78
12.78
183.
155823.7
0.627
1065.3
0.311
330.E
734.5
0.030A
12.75
12.75
184.
156558.1
0.628
1065.3
0.313
332.8
732.5
0.0308
12.72
12.72
185.
157290.6
0.630
1065.3
0.315
334.A
730.5
0.0308
12.68
12.68
186.
0.631
156021.0
1065.3
0.317
336.A
728.5
0.0308
12.65
187.
12.65
0.633
158749.4
1065.3
0.319
33869
726.4
0.0306
12.62
188.
12.62
159475.0
0.634
1065.3
0.321
341.0
724.3
0.0308
12.59
Subject TRANSPORT RATIO METHOD
12.59
189.
160200.1
0.636
1065.3
0.323
343.1
722.2
0.0309
12.56
12.56
190.
160922.3
0.638
1065.3
0.324
345.2
720.1
0.0309
12.53
12.53
191.
161642.3
0.635
1065.3
0.326
347.3
18.0
0.0309
12.50
192.
162360.3
12.50
0.641
1065.3
0.329
349.4
715.9
0.0309
12.47
193.
12.47
163076.1
0.642
1065.3
0.331
351.6
713.7
0.0309
12.44
194.
163789.0
12.44
8.644
1065.3
0.333
353.8
111.5
0.0309
12.41
195.
12.41
164501.2
0.646
1065.3
0.335
256.0
705.3
0.0309
12.38
196.
12.38
165210.5
0.647
1065.3
Date 9/86
0.337
359.2
707.1
0.0309
12.35
197.
165917.5
12.35
0.645
1065.3
0.335
260.5
704.8
0.0309
12.31
198.
166622.3
12.31
0.650
1065.3
0.341
362.7
702.6
0.0309
12.28
199.
167324.9
12.28
0.652
1065.3
8.343
365.0
700.3
0.0309
12.25
200.
168025.1
12.25
0.654
1065.3
0.345
367.3
698.0
0.0309
12.22
201.
168723.1
12.22
0.655
1065.3
0.347
369.6
695.7
0.0309
12.19
202.
169418.7
12.19
0.657
1065.3
0.3"0
272.0
693.3
0.0309
12.16
203.
170112.0
12.16
0.659
1065.3
0.352
374.3
691.0
0.0309
12.13
204.
170802.9
82.13
0.660
1065.3
0.354
376.7
68H.6
0.0309
12.10
205.
171491.4
12.10
0.662
1065.3
COMPUTATION SHEET
0.356
377.1
686.2
0.0309
12.07
206.
172177.5
12.07
0.664
1065.3
0.359
381.6
683.7
0.0309
12.04
207.
172861.2
12.04
0.665
1065.5
0.361
384.0
681.3
0.0309
12.01
200.
173542.4
12.01
0.667
1065.3
0.363
386.5
678.8
0.0309
11.98
205.
174221.2
Checked by
11.98
0.669
1065.3
0.366
359.0
676.3
0.0309
11.94
210.
174897.4
11.94
210.
174897.4
Project SHINNECOCK INLET
Date
Page 178 of 8
APPENDIX D
JETTY REHABILITATION AND REVETMENT
APPENDIX D
JETTY REHABILITATION AND REVETMENT
TABLE OF CONTENTS
Paragraph
Subject
Page
D1
General
D1
D2
Pertinent Data on Existing
D1
D3
Ocean Stillwater Level and
D2
Maximum Wave
D4
Existing Condition of the
Jetties
D2
D5
Existing Condition of the
Jetties - West Jetty
D2
D7
Existing Condition of the
Jetties - East Jetty
D3
D9
Future Condition of the
Jetties
D3
D10
Adequacy of Existing Jetties
D4
D13
Recommended Plan of Improvement
D5
D14
West Jetty
D5
D15
East Jetty
D5
D17
Revetment
D6
D19
Maintenance
D6
D21
Summary
D7
LIST OF COMPUTATION SHEETS
Description
Page
New Stone Revetment
D1 of 6
Scour Blanket
D4 of 6
Jetty Damage Levels
D5 of 6
i
APPENDIX D
JETTY REHABILITATION AND REVETMENT
D1. GENERAL. The existing condition of the east and west
jetties at Shinnecock Inlet and its history has been
evaluated using aerial photos, previous reports, condition
surveys in June 1984, April 1986, and numerous field visits.
Based upon the information provided by these sources, the
recommended plan of improvement for jetty rehabilitation was
formulated. Rehabilitation of the east & west jetties is in
accordance with the Shore Protection Manual 1984.
D2. Pertinent Data on Existing Structures.
a. East Jetty
1. Originally constructed to a length of about 1360
ft. in 1953 by the State of New York.
2. Crest Width 12 feet.
3. Crest elevation +7.8 N.G.V.D. (+9 mlw)
4. Jetty Trunk - Side Slopes one vertical on three-
halves horizontal.
5. Original stone units in head portion 6 to 12
tons.
6. Stone revetment 700 ft. long constructed in 1953
-2 to 4 ton stone.
b. West Jetty
1. Originally constructed to a length of about 850
feet in 1953 by the State of New York.
2. West Jetty extended to a total length of 950 feet
in 1954.
3. Crest width 12 feet.
4. Crest elevation +7.8 N.G.V.D. (+9 mlw)
5. Jetty trunk side slopes one vertical on three-
halves horizontal.
6. Original stone units in head portion 6 to 12
tons.
D1
7. Pile Crib revetment was constructed in 1939 at
the north end of the west side of the Inlet and
replaced by armor stone revetment in 1982.
D3. Ocean Stillwater Level and Maximum Wave. As defined in
the Cooperative Beach & Interim Hurricane Study, July 1958,
Atlantic Coast Of Long Island, New York, Fire Island Inlet to
Montauk Point, the design stillwater level was estimated as
the design hurricane surge or Standard Project Hurricane
Surge which is the total surge resulting from occurrence of
the 1944 hurricane on a path coincident with that of the 1938
hurricane moving with a forward speed of 35 mph resulting in
a surge level of el. +13.2 m.s.l. or 14.4 mlw This is a
maximum possible design stillwater level. However, as a
result of the bathymetry fronting the jetties as well as full
wave impact consideration, the maximum design wave height at
the jetty head were developed using a +12.0 m.l.w. design
stillwater level. Refer to Appendix C, Comp. Sheet C4 for
further analysis. The maximum impact wave to be added on to
the design stillwater is 16 ft. which would break on the
jetty heads; this wave would break before it reaches the
jetty trunk due to the shallow depths near the toe of the
trunk.
D4. Existing Condition of the Jetties. The east and west
rubble mound jetties at Shinnecock Inlet were constructed in
1953-1954 in an effort to stabilize the Inlet. Since that
time, the jetties have been appreciably damaged in sections:
the east jetty, in some locations, has been completely washed
out; rehabilitation of the west jetty was done in 1982.
Review of the jetty condition surveys has shown that
currently, aside from several isolated sections of
significant damage, the jetties are structurally stable. The
jetties have continued to stabilize the Inlet, however,
without rehabilitation they will continue to sustain damage
and at some future date, estimated to be as early as 10
years, may totally fail.
D5. A. West Jetty. Before the original construction of the
west jetty in 1953-1954, a pile crib revetment was built at
the north end of the west side of the Inlet in 1939
and was revetted with stone in 1947. This pile crib
revetment began failing in the 1960's and was in need of
complete rehabilitation by the late 1970's. In 1982,
Suffolk County Department of Public Works reconstructed the
pile crib revetment and part of the west jetty. The pile
crib revetment was replaced by a rubble mound jetty. One
hundred and seventy feet of the original jetty was
reconstructed and the capstones were reset to their original
design configurations.
D2
D6. Recent field investigation has shown that the portion of
the jetty which was rehabilitated in 1982 is in good
condition and has retained its 1982 design configuration.
Except for the jetty's outer end, there has been no sloughing
of the cap stones and good interlocking exists. The top of
the jetty has not settled, and there is no leakage of sands.
The outer portion of the west jetty has suffered damages
since 1954, and presently the seaward 200 ft. of the jetty is
unraveling which is connected with the development of scour
hole to el - 50 mlw at the jetty's outer end. The jetty head
has not retained its design configuration, and the capstones
have scattered.
D7. B. East Jetty. There has been no maintenance of the
east jetty since its construction. Considerable damage has
occurred at certain sections along the length of the jetty,
and continued damage is expected if repairs are not
undertaken.
D8. Along the length of the jetty, the stones on the Inlet
side are sustaining minor sloughing in some sections (shown
on Plate No. 4) while those stones on the beach side have
retained their original position. There are two isolated
areas of complete jetty washout at the northern end of the
jetty. Wave action and overwash from the Inlet has eroded
away the sand on the beach side of the jetty at these
washouts; continued loss of sand would further undermine the
existing jetty. As shown on Plate No. 4, there are areas
along the jetty which have had minor crest settlement and
some loss of interlocking of capstones. The shoaling
adjacent to the jetty is due primarily to sand traveling over
and thru the jetty at damaged sections. The most seaward 250
feet of the jetty is damaged and unraveling which is
connected with the development of a scour hole to elevation -
25 mlw at the jetty's outer end. The original 700 ft. of
revetment northeast of the jetty has completely washed away
and the shoreline is receding In addition, due to the
strong bay currents especially on the ebb tide which flow in
close proximity to the shoreline north and east of the Inlet,
significant scouring has occurred to the bay shoreline within
approximately 1,000 ft. east of the Bay end of the jetty.
This scouring has resulted in a shoreline recession rate of
approximately 15 ./year which could lead to a breach
through the barrier beach at some future time, perhaps 20 to
30 years, as occurred at Moriches Inlet in 1980. More
immediately, continued erosion in this area will contribute
to undermining the northern section of the jetty. In
summary, aside from the failing outer and failed inner
sections, the majority of the jetty, although sustaining
damage has continued to perform adequately.
D9. Future Condition of the Jetties. Based on field
inspections in December 1983, April 1984, June 1985 and March
1986 and photo inspections of August 1954, March 1956,
D3
November 1968, April 1973, December 1978, November 1980 and
March 1982, there have been two rates of damage established
in order to project the future condition of the east jetty
without jetty rehabilitation. The east jetty is considered
the key to future conditions since it is further along in its
deterioration than the west jetty. A long term rate of
damage to initially isolated damaged sections which is
approximately 30 feet/year since 1954 has not caused jetty
failure but has weakened its condition and led to a shorter
term rate of more severe damage, which is proceeding at the
rate of approximately 100 ft/year since April 1984 and is
projected to cause jetty failure as early as 10 years.
Subsequent to jetty failure, it is estimated that sand from
behind the jetty will infringe the Inlet in 4 years.
D10. Adequacy of Existing Jetties. The existing stone sizes
of the armor layer of both jetties at their head sections
vary from 6 to 12 tons, which are adequate for an 11.8 foot
breaking wave, based on Hudson's Equation (SPM pg. 7-205).
The maximum depth-limited wave which could break on the jetty
head (which would be the design wave height) is a 16 foot
wave. The ratio of wave (H=11.8 ft.) heights between the
0% - 5% damage condition (H =16.0 ft.) and design height
(h=11.8 ft.) for existing conditions results in damage rates
that are within Corps of Engineers limits of acceptability
(30%) from SPM Section 7E. However, additional jetty
maintenance costs, further discussed in paragraph D8 have
been included in the rehabilitation scheme to account for the
higher than Corps designed damage levels. The cover layer
slopes of 1 on 1.5 are acceptable to Corps criteria for slope
stability. Both jetties have only one layer of armor stone
which is not in compliance with the Shore Protection Manual
(1984) design criteria for breaking waves at head sections
which specifies that two layers of armor stone are necessary
in rubble structure design. This lack of sufficient cover
layer stone and the scouring of the underlying sand at the
oceanward toe of each of the jetties has lead to the
unraveling of the head sections of the jetties. The
configuration of the jetty which replaced the west jetty pile
crib revetment is acceptable to Corps criteria, and the stone
sizes are acceptable for the wave climate at that part of the
Inlet.
D11. The east and west jetties have accomplished their
purpose of stabilizing Shinnecock Inlet. They have kept the
beach fill in place on either side of the Inlet. Based on a
review of photographs as well as numerous site visits, it was
determined that generally the jetties are not leaking any
significant amount of sand. The sand located on the Inlet
side of the east jetty's toe has been deposited there
primarily by movement of sand over the crest of the jetty and
thru severely damaged jetty sections.
D4.
D12. In summary, the jetties are adequately sized, but need
an extra layer of capstone at the head sections to meet Corps
criteria. This, along with increased maintenance costs
have been incorporated into the jetty rehabilitation plan.
D13. Recommended Plan of Improvement. To rehabilitate the
jetties at Shinnecock Inlet, specific repairs are recommended
to prevent the structural failure of the jetties. All
damages detailed in the existing condition section will be
repaired so that the jetties will be able to keep the Inlet
stable and to permit continued navigation of the Inlet. The
plan of rehabilitation is displayed in Table B3 of the Cost
Appendix and Plate No. 4.
D14. A. West Jetty. The oceanward two hundred foot section
of the west jetty will be repaired as follows. A four foot
thick scour blanket of 800 pound stone will be laid on the
existing bottom over approximately 38,000 square feet to
prevent additional scouring at the oceanward toe of the
rehabilitated jetty. Refer to Comp. Page D4. New capstone
and core stone will be needed to supplement the displaced
stones of the existing jetty's 200 ft. outer end. The
rehabilitation of the outer most 50 ft. will be upgraded from
the as-built 1 layer of 6 to 12 ton cap stone with 1 on 1.5
slope to 2 layers of 12 ton avg. cap stone with 1 on 2 slope
in order to reduce damage levels to 25% as per SPM sect. 7E.
Refer to Plate No. 5 for details.
D15. B. East Jetty. Major repairs are necessary at certain
sections on the east jetty to assure that it will not fail in
the future.
D16. To replace the jetty section (approximately 200 feet in
length) at the northern end of the jetty where there has been
complete or partial washout, new capstone, corestone and
bedding will be required for restoration. The new capstone
for this section has been upgraded from the minimum 4 ton as
built condition to a minimum 6 ton project improvement design
to preclude washout. It is to be noted that washout of this
section of jetty is believed to have been significantly
impacted by washout of 700 ft. of adjacent revetment from a
severe 1954 storm and subsequent flanking. As stated in
paragraph D7c, the design of the revetment section to replace
washed out revetment has also been upgraded to a jetty
section to preclude washout. In addition, the rebuilt jetty
alignment in this section of washout has been shifted from
its original alignment to avoid proximity of a scour hole.
In other sections where settlement and sloughing of the jetty
stones have occurred (a total of approximately 730 feet), the
original cap stones will be removed and core and bedding
supplemented and stabilized and capstone reset to insure
interlocking of the stones. Stone size will not be upgraded
in this section since performance has been adequate with
D5
acceptable damage levels. Similar to the west jetty, a 250
ft. outer section of the east jetty will have to be totally
rebuilt with the rehabilitation of the outer most 50 ft.
upgraded to 2 layers of 12 ton avg. capstone with a 1 on 2
slope in order to reduce damage levels to 25%. A scour
blanket for toe stability will be placed consisting of a
4 ft. thick armor stone layer over 60,000 s.f. of ocean
bottom at the outer toe of the jetty. Refer to Plate No. 5
and Comp Page D4 for details.
D17. C. Revetment. In addition to the work recommended on
the jetties, 260 ft. of revetment north east and adjacent to
the east jetty will replace a washed out section of
revetment. It is to be noted that this revetment section has
been upgraded in design to a trapezoidal section with 6 ton
minimum capstone size to preclude the type of washout that
previously occurred.
D18: In order to preclude erosion on the Bay side of the
barrier beach adjacent to the east jetty, a new section of
revetment, 1,000 ft. long as shown on Plate No. 5, is
recommended. Due to its location, no direct ocean influence
is anticipated on this length of revetment and therefore, was
designed for Bay conditions. The SPM and EM-1110-2-1614,
"Design of Coastal Revetment, Seawalls and Bulkheads" were
utilized for the design of the new revetment and shown on
Computation Sheet No. D1. Design computations are shown on
Comp. Page D1. It is to be noted that the location of 260
ft. of revetment to be replaced (indicated in the previous
paragraph) required a design with ocean influence, unlike the
new revetment which totally faces the Bay and is sufficiently
distant from wave influence from the Inlet. In addition, the
top elevation of the revetment has been set at el. +9 mlw
(the crest elevation of the adjacent jetty). This allows for
a 25 year bay surge level and a runup of 1.5 ft. Even
though, with design project hurricane ocean surge levels,
submergence of the structure could occur, it is not cost
effective to extend the top el. to +13 mlw for this condition
as compared with including a higher maintenance cost for a
top of revetment elevation of +9 mlw.
D19. Maintenance. Stone structures designed from Corps
criteria are anticipated to sustain a 0% to 5% range of
damage. Customarily, annual maintenance of a Corps designed
stone structure is estimateed to be 0.5% of its first cost.
Since the jetties are not designed to Corps criteria but are
anticipated to sustain an acceptable damage rate of 25%, the
annual maintenance cost have been increased to 2.0% of first
cost to allow for the anticipated higher level of damage.
D20. Since the new 1,000 ft. revetment adjacent to the east
jetty was designed from Corps criteria with the additional
condition that submergence could occur with design project
D6
hurricane ocean surge levels, a 1.0% of the first cost for
annual maintenance costs has been included.
D21. Summary. It is expected that upon rehabilitation of the
east and west jetties and periodic maintenance provided
thereafter, the jetties will continue to function as a
navigation structure without excessive damage, as has
occurred historically without the benefit of periodic
maintenance.
D7
COMPUTATION SHEET
Page DI of 6
Subject New Stone Revetment
Project Shinnecock Inlet
Computed by Ac
Date 9/19/86
Checked by LMK
Date 9/22/36
E1.+9.O
TO THE INCH
mym
Graded riprop
W50= = 150#
5
1.9'
5 X 5
m.l.w.V
/
SQUARE
E/.t) E/W5ml.w. 5ml.w. =
4'
MCKNOO
3
1-8'21
From Computation Sheet C-5, the following
design conditions are applicable:
Design wave height (H)= 3.3ft.
Design stillwater level = +6.0 NGVD(+7.3mlw)
(incl. surge $ (tide)
Design wave period(T) = 3.2 seconds
From EM 1110-2-1614:
riprap revetment:
To determine weight of store for graded
W50= = to H3
(miny (Sr-1) cote
where
5r specific gravity of stone
8r N unit weight of stone,
H= design wave height
KD2 stability coefficient
thus
Oz structure slope
NANY FORM 229 Apr 79
W50 = (172)(3.3)³ = 120# # say 150#
(min)
COMPUTATION SHEET
Page DZo1 6
Subject New Stone Revetment
Project Shinnecock Inlet
Computed by se
Date 9/19/86
Checked by LMK
Date 9/22/86
For the revetment layer thickness:
0.33
TO THE INCH
Fmin. = 2.0( W50mm) rr
5X5
5
=
20(150)
150
0.33
2.0
= 1.9 Ft.
SOUARE
172
To determine the top el. of the revetment,
the runup must be colculated as
follows from Chapter 7, Section II of the SPM:
The equivalent deepwater wave height (Ho)
of the design wave must first be Icalculated
Usina a deepwater depth Cin the Baylof 10H:
of Lo =
7
- M
10
"
01907
(5.12) TC
(5.12/3.2)
From Table C.Z of SPM
H/Ho's 9162
for 14=3,3
Horz 3.3/g 9162 = 3.60
Ho'z 3.6
2
.0109
gTc (322)(3.2)²
For a depth of water at structure toe
dsz 5+ 7.3 = 12.3
&
ds/ Hj' = 12.3/3 3.6 Z 3.42
NANY FORM 229 Apr 79
From Fig. 7-12 (SPM) for cot.a=5 D=
R/H. = 0.73 or
R = (0.73)(3.6) 7 2,6 = runup on slope a smooth
COMPUTATION SHEET
Page D3016
Subject New Stone Revetment
Project Shinnecock Inlet
Computed by se
Date 9/19/86
Checked by LMK
Date 9/22/86
graded riprop slope refer to Fig. 7-19 (SPM).
To calculate the runup on the given
SQUARE Б TO THE INCH
[R/H.] R Bra lon2 slope = 1.0
5 X 5
riprap
From Fig. 7-12 (SPM) for a lonz slope
[R/Ho smooth 24 1.75
Now to determine the reduction Arunop
slope based on a riprapped slope vs. a smooth
[R/4 riprap
1.0
N
= 0.57
[R/H.],mooth [R/H. Jsmooth
1.75
slope:
Therefore the runup on a graded riprap
riprap = = (0.57)(2.6)
= 1.5 H.
Thus the top el. of the revetment
15 the design SWL (ricluding surge of tide)
T/Rev.El.=+ 7.3 m/w +1.5ft 2+8,8m.lw
plus runup
say +9,0 m/w
NANY FORM 229 Apr 79
COMPUTATION SHEET
Page DA 016
Subject Scour Blanket
Project Shinneoock Inlet
Computed by se
Date 9/19/86
Checked by LMK
Date 9/22/86
To determine the stone size for the
scour blanket, refer to Section IV of
TO THE INCH
Chapter 7 of the SPM which defines
revetment stone weight design based on
X5
velocity criteria,
Equation 7-142(5PM) states that the min.
SQUARE
Height of stable sTone =
We
0.0219
6
800
W
)(1-31n28
/-
20
3/2
2
g3
on-rw
sin20
where V onstine
fre unit
8w= unit weblit of water
9 angle of structure slope
acceleration of gravity
& = riprap angle of repose
This equation uses Isbashs corfficient
voluerof 1.20 fgr embedded stone The
equation therefore should be corrected
non embedded stone. This results in
Lusing Isbashs value If 0.86 for
an adjusted Cg 7-142 of
W 1617 V6 Dr
Dw
sin
20
93
)
-3/2
sin
at both jetty ends the
Using A V=10 Fes developed m Appeadix C,
max $2=40': 6=26.6 ( / m 2 s pe) from hydrographic 7-3/2 survey
W=(,1617)(10)
(.1617)
172
(32.2)
L
64
1-6.50)-
NANY FORM 228 Apr 19
172-64
(643)3
recommended = 713# pay 800#; N layers are
Therefore the scour blanket stone sizes at
both jetty heads are N layers of 800#store.
COMPUTATION SHEET
Page D5. of 6
Subject Jetty Damage Levels
Project Shinnecock Inlet
Computed by Ae
Date 9/19/86
Checked by LUNK
Date 9/22/86
TO THE INCH
with project improvements jetty
To determine anticipated damage leyels
head's the stone size is 12 ton units
(Z layers, with : a /on 2 side slope. Using
5X5
X
Hudson's Eg.
SQUARE
Hz [W Ko (Sr-1) Xr cot of 3
where W Stone weight
KDA Stability coefficient
Sr = Specifie weight of stone
rr = unit weight of stone
Dz structure slope
thus
172 273
= 12.1 Ft. M Wave height that can be
the jetty
resisted by a breaking move of
However, based on Appendex C, the max.
design wave that couldbreak on the ieth
heads is 16.0 Pt. The associated damages
levels for a structure designed for a 16.0ft
SPM Since the structure can resist
breaking wave 15 0,6 too 56 based on
anticipated damage levels would increase
levels, byusing max wave OT 16.0 ft, the
up to a 12.1ft. wave with 0% to 5% claimage
to 25% based on Table 7-9 for
NANY FORM 229 Apr 79
H/ H020 = 16.0/77 12.1 = 1,33
COMPUTATION SHEET
Page D6 of 6
Subject Jetty Damage Levels
Project Shinnecock Inlet
Computed by pe
Date 9/19/86
Checked by Lark
Date 9/22/36
To determine the damage levels at the
Jerry trunk with 6 ton min. stone size
SQUARE 5X5 TO THE INCH
/ on 1.5 slopes using Hudson's Ea.
size & slope
for wave height associated with given stone
H2 / WK (Sr-1) rr coto 27"
N
172
= 10.4 ft.
From Appendix C, for a SWL = =+12.0 m/w
the and max depths wave at associated the jetty toe with averaging depth limitations (-)5 m.w,
at the toe IS (.78)(17)? 133 ft.
Therefore from SPM, Table 7-9
for H/ How = 13.3, 104 = 1.28 or
the condition jetty trunk subjected to a max. wave
15%-20% anticipated, damage levels for
NANY FORM 229 Apr 79
APPENDIX E
SHINNECOCK INLET NAVIGATION STUDY
ECONOMIC ANALYSIS
APPENDIX E
SHINNECOCK INLET NAVIGATION STUDY
ECONOMIC ANALYSIS
TABLE OF CONTENTS
SECTION
TITLE
PAGE
I
Introduction
E 1
Terminology
II
General Navigation Conditions in the Inlet
E 3
Historical Inlet Conditions
Existing Inlet Conditions
III
Commercial Fishing Evaluation
E 4
Data Collection
Existing Commercial Fishing
Boat Usage
Fish Landings
Fish Capacity
Without Project Condition
With Project Conditions
Future Commercial Fishing Fleet
Damage to Commercial Facilities
Benefit Analysis
IV
Head Boat Evaluation
E26
Head Boat Operating Characteristics
Historical Conditions
Existing Head Boat Usage
Without Project Conditions
With Project Conditions
Future Head Boat Fleet
Benefit Analysis
V
Charter Boat Evaluation
E31
Charter Boat Operating Characteristics
Existing Charter Boat Usage
Without Project Conditions
With Project Conditions
Future Charter Boat Fleet
Benefit Analysis
1
TABLE OF CONTENTS (CON'T)
TABLE
TITLE
PAGE
VI
Recreational Boating Evaluation
E34
Existing Recreational Boat Usage
Without Project Conditions
With Project Conditions
Future Recreational Fleet
Benefit Analysis
VII
Benefit Summary
E39
Benefit Summary
ii
SHINNECOCK INLET NAVIGATION STUDY
ECONOMIC ANALYSIS
LIST OF TABLES
TABLE
TITLE
PAGE
1
SHINNECOCK INLET, VESSEL OPTIMAL OPERATING
E 6
PROFILE, EXISTING FLEET (JAN. 1986)
2
SHINNECOCK INLET, FISH LANDINGS 1983
E 8
THROUGH 1986
3
SHINNECOCK INLET 1986 FISH LANDINGS
E 9
BY AREA
4
1986 SHINNECOCK INLET LANDINGS (BY SPECIES)
E10
5
SHINNECOCK INLET, WHERE FISH CAUGHT IN AREA
E12
613 WERE LANDED IN 1984 (NON-SCALLOP
LANDINGS)
6
SHINNECOCK INLET, FISHING CONDITIONS
E13
7
SHINNECOCK INLET, POTENTIAL FOR INCREASED
E14
CATCH FOR VARIOUS FISHERIES
8
SHINNECOCK INLET, LANDINGS USING ALTERNATE
E17
PORTS (WITHOUT PROJECT CONDITION)
9
SHINNECOCK INLET, CALCULATION OF ANNUAL
E18
COST UNDER BOTH WITHOUT PROJECT AND WITH PROJECT
CONDITIONS
10
SHINNECOCK INLET, ANNUAL NET INCOME
E19
ALTERNATIVE PORT (WITHOUT PROJECT CONDITION)
11
SHINNECOCK INLET, ANNUAL LANDINGS UNDER WITH E21
PROJECT CONDITIONS FOR EXISTING FLEET
12
SHINNECOCK INLET, ANNUAL PROFITS UNDER
E23
WITH PROJECT CONDITIONS FOR EXISTING FLEET
13
SHINNECOCK INLET, NET INCOME WITH PROJECT
E24
CONDITIONS FOR NEW FLEET
iii
TABLE
TITLE
PAGE
13A
SHINNECOCK INLET, DAMAGE TO COMMERCIAL
E25
FACILITIES
14
SHINNECOCK INLET, COMMERCIAL FISHING
E27
BENEFIT CALCULATION
15
SHINNECOCK INLET, PROJECTED INCOME FOR
E28
ATTRACTED HEAD BOATS
16
MAJOR HEAD BOAT AND CHARTER BOAT DOCKS
E30
17
CHANGE IN CHARTER VESSELS INCOME IN
E32
SHINNECOCK INLET UNDER VARIOUS ALTERNATIVES
SHINNECOCK INLET, INCREASED COST BY USING
E36
18
MONTAUK MARINAS
SHINNECOCK INLET, INCREASED COST BY GOING
E37
19
THROUGH MORICHES INLET
20
SHINNECOCK INLET, SUMMARIZATION OF BENEFITS
E40
iv
Shinnecock Inlet
Economic Appendix
I. Introduction
This appendix is prepared in accordance with the Water
Resources Council's Economic and Environmental, Principles
and Guidelines, for Water Related Land Resource
Implementation Studies, dated March 1983. It presents an
evaluation of the benefits that would result from the
proposed plan of improvement for Shinnecock Inlet. The plan
of improvement is described in detail in the main report.
Briefly, the plan consists of an entrance channel 10 feet
deep at mean low water and 200 feet wide from that depth in
the Atlantic Ocean to Shinnecock Bay, a distance of
approximately .7 miles.
Previous studies of Shinnecock Inlet identified several
categories of benefits that might result from various plans
of improvement. Appendix B, Evaluation of Benefits,
contained in the Survey Report, Moriches and Shinnecock
Inlet, Long Island, New York, dated September 1957 and
revised 11 July 1958 presented the following categories of
benefits.
a. Increased fish and shell fish catch in the
ocean.
b. Increased shell fish production in Moriches,
Shinnecock and Great South Bays.
C. Use of the inlet by pleasure and sport fishing
boats.
d. Reduction of vessel damage.
e. Provision for access to harbors of refuge.
f. Control of beach erosion.
g. Pollution abatement.
h. Increased bay recreational boating.
This appendix will treat the following navigation
categories:
El
1. Commercial fishing benefits.
2. Benefits from the protection of navigation facility.
3. Recreational fishing benefits.
Many of the categories included in the original survey
report are no longer applicable. For example, pollution
abatement was not analysed because it was based on the
assumption that the plan of improvement would significantly
improve the water quality in Shinnecock Bay. However, water
quality in Shinnecock Bay has significantly improved since
the 1957 survey report. The New York State Department of
Environmental Conservation has currently rated the bay water
"suitable for shell fishing for market purposes and primary
and secondary contact recreation." Other categories were
also eliminated because they would not be realized with the
recommended plan of improvement. Changes in the Planning
Guidance Notebook and the actual activities within Shinnecock
Inlet during the last thirty years also mandated a
reclassification of the benefit categories.
Terminology -In this appendix ocean conditions are described
as calm, normal and adverse. The percentages of time that
these conditions occur were provided by the United States
Coast Guard and confirmed by local fishermen. These terms
are explained below:
Calm - Calm conditions are characterized by minimal waves
and swells. If the channel depth is sufficient, vessels will
not have problems utilizing the inlet. With sufficient
depth, a vessel could easily and safely navigate the inlet.
Calm conditions are estimated to occur about 5 percent of the
time.
Normal - Normal conditions comprise the range between adverse
and calm reflecting the majority of ocean usage. These
conditions occur approximately 60 percent of the time.
Under the without project conditions during normal ocean
conditions the inlet will be unsafe and dangerous to navigate
for all users. Under without project conditions the waves
and swells would be significantly greater than under an
improved condition. Normal conditions are reflected by 1.5
foot wave activity under an improved condition.
Adverse - Under adverse conditions the inlet is unsafe and
dangerous because of weather or bad sea conditions. A plan of
improvement would not alleviate this danger. This condition
E2
occurs approximately 35 percent of the time. Adverse
conditions are not affected by the tidal cycle.
II. General Navigation Conditions In The Inlet
Historical Inlet Conditions - Fishermen and marina operators
stated that as long as twenty years ago, there were few
problems entering or leaving the inlet during normal ocean
conditions. All vessels which were not constrained by depth,
were able to leave and enter at any time. There was
sufficient depth in the inlet for the historic fleet. In the
1970's, breakers began to occur in the inlet. Breakers are
caused by insufficient channel depth for the ocean currents
and waves passing through the channel. Because of their
nature, breakers are usually minimized near high tide, and
because tide is predictable, breakers have an element of
predictability. Vessel captains indicated a preference to
enter and leave at high tide. Siltation was filling in the
inlet and causing it to become shallower and narrower. This
was causing the breakers to occur more often and encroach
across the inlet.
Existing Inlet Conditions - Commercial fishing boats, charter
boats, and private recreational boats currently use
Shinnecock Inlet. Potential navigation benefits are
applicable to all users of Shinnecock Inlet because no user
is immune to the navigation problems within Shinnecock Inlet.
Under calm conditions, no wind or waves, the large
commercial fishing vessels go through an existing 100' wide
slot in the sandbar. The slot is 13.5 feet deep mean low
water. The largest fishing vessel draws 11.5 feet. Two feet
are available for safety clearance at low tide. The largest
fishing vessels are approximately 22 feet wide. The
remaining vessels, the charter boats and recreational boats,
navigate the sand bar without difficulty under calm
conditions.
Under normal conditions, there are two lines of breakers
across the front of the inlet. The deepest water forms a
navigable slot between the breakers for boats to enter and
leave Shinnecock Inlet. This navigation requires total
knowledge of the inlet and competent seamanship to use the
meandering path. Charter boats and private recreational
boats do not go over the sand bar because it is dangerous due
to the breaker line during normal ocean conditions. None of
the vessels are constrained by the depth of the channel.
E3
Under the range of normal conditions that currently
exist, superior local knowledge and seamanship is required to
safely go through the slot. There is risk of damage to the
vessel and possible injury to the boaters. Recreational
boaters and charter boaters on occasion do refrain from
leaving under existing normal ocean conditions. Commercial
fishing vessels do try to operate under these conditions,
because the vessels are more durable than the recreational
vessels. Their captains are professional seamen with
superior local knowledge. They also have the flexibility to
wait for high tide to minimize the breaker problem.
On occasion during normal ocean conditions in the current
inlet, a strong wind or a storm tide will make the risk of
operating excessive even for commercial fishing boats. This
disrupts the schedule of the fishermen because the sea beyond
the breakers is calm and suitable for fishing. This results
in lost fishing time.
The navigable slot is difficult to utilize because the
slot shifts frequently, and if poor weather conditions exist,
the slot can shift in several days. When the commercial
fishing vessels go through the slot, there is no room for
maneuvering due to the narrowness and meandering of the
channel. Captains using the inlet indicated that boats often
hit the side of the slot. A vessel that goes through the
slot, makes its commitment a significant distance before it
reaches the slot. Turning around under dangerous sea
conditions risks capsizing the vessel. In 1985, several
vessels were damaged in or near the navigable slot.
Approximately $10,000 worth of damages were reported. In
other cases, the inlet was so dangerous that vessels either
stayed in Shinnecock Bay or stayed at sea, but, they neither
entered nor left Shinnecock Bay by way of Shinnecock Inlet.
The specific existing conditions for various types of vessels
are described in the following sections.
III. Commercial Fishing Evaluation
Data Collection - Data on the commercial fishing operations
detailed in following analysis was collected from a variety
of sources. Existing condition information reflects the
actual fleet currently in Shinnecock Inlet. Interviews were
conducted with fishermen and captains of the existing fleet
to collect data consisting of vessels operating practices,
such as the actual time and character of the fishing trips.
This information included the time spent fishing, based on
E4
the size of the vessel, the speed of the vessel, the size and
type of crew on board, and the average amount of fish
landings. This information was further verified by site
visits to the inlet and field observations of vessels
utilizing the inlet.
Cost data utilized in the analysis was provided primarily
by the fishermen and users of the inlet, relative to specific
vessel size. The data was more broadly confirmed by the
Fishermen's Wive Association. This organization monitors the
fishing activity in the inlet and is well informed regarding
inlet operations. Some specific cost data such as insurance
costs, maintenance costs and moorage costs were initially
derived as a percent of vessel value, as done in the
Institute of Water Resources guidance, dated 31 August 1983,
on Shallow Draft Vessel Costs. These figures were then
modified to reflect site specific costs incurred at
Shinnecock Inlet.
To further verify the data used in the economic analysis,
the National Marine Fisheries Service (NMFS), Analytical
Services Branch, was contacted to insure that the figures
utilized were consistant with data collected by their office,
data used in other NMFS studies and data from other North
Atlantic fishing operations.
Existing Commercial Fishing Boat Usage - Commercial fishing
boats are the largest vessels going through Shinnecock Inlet.
Optimal operating characteristics in an unrestricted channel
are described in Table 1. The range of drafts for 70-79 long
vessels actually varies from 8.5 feet to 11.5 feet. Most of
the fishing boats over 70 feet use high tide to enter and
exit the inlet. It is important to note that vessels do not
utilize the tide because of an existing depth constraint.
The additional available water depth simply improves the
navigability of the narrow slot.
Under normal sea conditions, when the sea is rough enough
to increase the risks of utilizing the inlet, vessels very
often refrain from going out. Occasionally, vessels may have
to wait to enter. Disruptions in the commercial vessels
schedules effects the current profitability of the fleet.
The majority of all fish shipments leaving Shinnecock Inlet
are scheduled for Thursdays because the commercial fleet
largely service the Fulton Fish Market in New York City. The
fish are transported by truck from Shinnecock to New York
City. The trucks routinely leave before dawn on each Friday.
The Fulton Fish Market and other large fish markets used for
E5
TABLE 1
SHINNECOCK INLET
VESSEL OPTIMAL OPERATING PROFILE
EXISTING FLEET (JAN. 1986)
DESCRIPTION
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+
TOTALS
DRAFT
5
7
8
10
10.5
BEAM
12
17
19
21
23
SPEED(KNOTS)
8
8
8
8
8
VESSEL COSTS
$50,000
$125,000
$150,000
$200,000
$500,000
LIFE (years)
20
20
20
20
20
NUMBER OF DAYS FISHING
160
180
200
210
220
X
x
X
x
X
HOURS FISHED PER DAY
12
24
24
24
24
88
=
10
=
=
TIME SPENT FISHING(HOURS)
1920
4320
4800
5040
5280
TIME SPENT PER FISHING TRIP
12
32
36
42
53
(HOURS)
NUMBER OF TRIPS
160
135
133
120
100
CREW SIZE
AVERAGE
2
3
3
4
8
NUMBER OF FISHING VESSELS
14
9
9
10
to
46
LANDINGS PER TRIP
$313
$926
$1,128
$1,667
$5,000
E6
wholesale distribution are closed during the weekend.
Therefore, if the fishermen miss this schedule, the fish
cannot be sold until Monday morning. This significantly
reduces the value of the catch.
Fish Landings - Fish catches for Shinnecock Inlet are shown
in Table 2. For Shinnecock, the great majority of fish come
from NMFS area 613, some from NMFS 616 and small amounts from
other areas. Fishing areas are displayed in Figure 1.
Landings for Shinnecock Inlet, by area are displayed in Table
3. The actual fish landed in Shinnecock Inlet are displayed
in Table 4. Shinnecock Inlet lands whole fresh fish from
short trip vessels. Most of Suffolk County area 613 finfish
landings are through Shinnecock Inlet.
Table 5 shows that for area 613, in 1984, approximately
two thirds of its landings, $5,700,000, were in Suffolk
County. About $1,750,000 worth of fish were landed in Rhode
Island and $400,000 combined in the nearby New Jersey
counties of Monmouth and Ocean. Under $4,000 worth of fish
were landed in Nassau County.
Table 6 shows landings for the existing fleet at
Shinnecock Inlet assuming fishing vessels continue to operate
under the deteriorating conditions. Under January 1986
conditions, even though approximately 25% of the fishing
opportunities are anticipated to be lost because of dangerous
inlet conditions, expected landings for the fleet equal
approximately $5.4 million. Actual landings were $5,500,000.
This minor discrepancy between estimated and actual landings
is caused by minor variations in actual vessel operations.
Since the unnavigable conditions are caused by the breakers
and the narrowness of the channel, analysis by vessel draft
is not applicable, and all commercial vessels are affected
equally in the analysis.
Fish Capacity - In order for inlet conditions to impact
commercial fishing, there must be fish available for
harvesting. Therefore, sustainable yield was estimated. The
National Marine Fisheries Service has estimates of
sustainable yield for various fisheries, but they are not
broken down by NMFS area.
Estimates of sustainable yield for the major economic
fish species excluding scallops are contained in Table 7.
These species accounted for three quarters of Suffolk County
NMFS area 613 non-scallop landings. Table 7 shows that
sustainable yield is approximately 1.79 times the $4,600,000
E7
TABLE 2
SHINNECOCK INLET
FISH LANDINGS 1983 THROUGH 1986
YEAR
WEIGHT
VALUE
(LBS)
$
1983
8,350,000
$4,400,000
1984
8,200,000
$4,600,000
1985
9,100,000
$5,500,000
1986
8,334,000
$5,524,000
SOURCE: NATIONAL MARINE FISHERIES SERVICE
E8
TABLE 3
SHINNECOCK INLET
1986 FISH LANDINGS BY AREA
AREA
POUNDS
VALUE
613
6,166,000
$3,995,000
616
1,794,000
$1,313,000
537
321,000
$152,000
611
40,000
$29,000
525
5,000
$18,000
533
8,000
$17,000
TOTAL
8,334,000 $5,524,000
SOURCE: NATIONAL MARINE FISHERIES SERVICE
E9
TABLE 4
1986 SHINNECOCK INLET LANDINGS
FISH
POUNDS
VALUE
Anchovies
65
$10
Anglerfish
79,197
$74,775
Bluefish, Unc
237,059
$61,813
Bonito
5,414
$2,571
Butterfish, Lg
120
$124
Butterfish, sm
23,815
$4,876
Butterfish, unc.
271,449
$153,797
cod, At, Unc
187,237
$189,962
Dolphinfish
20
$38
Eels, Common
6,307
$8,979
Eels, Conger
10
$5
Flounder, At, Blackback, Unc
149,999
$130,512
Flounder, At, Flukd, Jumbo
905
$1,486
Flounder, At, Fluke, Lg
1,292
$2,140
Flounder, At, Fke, Unc
850,487
$1,291,334
Flounder, At, Fluke, Md
4,665
$7,741
Flounder, At, Gray sole, Unc
1,705
$1,883
Flounder, At, Sand
45,675
$15,474
Flounder, At, Yellowtail, Lg
2,805
$2,999
Flounder, At, Yellowtail, sm
5,160
$3,842
Flounder, At, Yellowtail, Unc
176,590
$158,892
Hake, At, Red
51,693
$17,325
Herring, At, Sea
845
$174
Mackerel, At
355,842
$41,384
Marlin, Blue
900
$225
Menhaden, At & Gf
17,100
$1,863
Ocean Pout
730
$183
Pollock, At & Pa, Unc
198
$76
Scups or Porgies, Lg
6,100
$6,842
Scups or Porgies, Md
15,790
$14,791
Scups or Porgies, Sm
2,635
$2,537
Scups or Porgies, Unc
621,940
$565,175
Sea Basses, At, Black, Lg
735
$1,286
Sea Basses, At, Black, Sm
375
$656
Sea Basses, At, Black, Unc
75,035
$110,510
Sea Robins
595
$119
Sea Trout, Gray, Unc
79,549
$69,604
Shad, Unc
4,392
$1,248
Sharks, Dogfish, Unc
63,546
$21,463
Sharks, Unc
1,086
$1,363
Sharks, Thresher
125
$125
Sharks, Dogfish, Spiny
101,760
$6,106
Skates
74,751
$5,933
Spanish Mackerel
1,042
$831
Sturgeons, Comm-Green & White
12,121
$9,386
Swellfish (Tails)
400
$1,708
Swordfish
22,235
$77,236
E10
Tautog
13,996
$6,135
Tilefish
142
$240
Tuna, Albacore
1,900
$1,215
Tuna, Bluefin, unc
75
$281
Tuna, Yellowfin
15,935
$22,726
Tuna, Unc
260
$221
Tuna, Big Eye
300
$1,023
White Perch
830
$445
Whiting, Unc
1,131,057
$472,010
Finfishes, Unc, Bait, An. Food
1,923
$96
Crab, Jonah (Claws)
100
$100
Horseshoe Crab
100
$5
Lobster, American, Unc
17,875
$53,157
Clams, Ocean Quahog
2,890
$1,012
Clams, Soft, Public
1,216
$3,967
Clams, Unc
102,168
$418,166
Mussels, Sea
19,190
$19,440
Oyster, East. Mkt, Pbl, Fall
1,440
$6,725
Scallop, Sea
1,970
$10,439
Squid, Long Finned
3,458,913
$1,434,980
8,333,776
$5,523,785
Ell
TABLE 5
SHINNECOCK INLET
WHERE FISH CAUGHT IN AREA 613 WERE LANDED IN 1984
(NON SCALLOP LANDINGS)
COUNTY AND STATE
POUNDS
VALUE
VALUE / POUNDS
CUMBERLAND, MAINE
3,300
$1,336
$0.40
BRISTOL, MASS.
434,700
$253,819
$0.58
NEWPORT, RHODE ISLAND
1,873,200
$1,110,359
$0.59
WASHINGTON, R. I.
1,423,500
$645,448
$0.45
ATLANTIC, N. J.
0
$0
CAPE MAY, N. J.
80,000
$19,852
$0.25
MONMOUTH, N. J.
194,600
$210,169
$1.08
OCEAN, N. J.
472,900
$197,057
$0.42
NASSAU, N. Y.
1,000
$3,594
$3.59
WORCESTER, MD
0
$0
NEWPORT NEWS, VA
33,800
$18,123
$0.54
CITY OF HAMPTON, VA
161,400
$66,623
$0.41
YORK, VA
98,900
$40,403
$0.41
TOTAL NON SCALLOP LANDINGS
(EXCLUDING SUFFOLK CO)
4,777,300
2,566,783
$0.54
PERCENTAGE OF TOTAL
31%
31%
NON SCALLOP LANDINGS
FOR SUFFOLK COUNTY
10,700,000
$5,700,000
$0.53
PERCENTAGE OF TOTAL
69%
69%
TOTAL NON-SCALLOP LANDINGS
15,477,300
$8,266,783
$0.53
E12
TABLE 6
SHINNECOCK INLET
FISHING CONDITIONS
LANDINGS UNDER EXISTING CONDITIONS
LENGTH
40.49
50.59
60-69
70-79
80+
NUMBER OF DAYS FISHING
160
180
200
210
220
(OPTIMAL)
% LOST BECAUSE OF INLET
25%
25%
25%
25%
25%
ACTUAL DAYS FISHING
120
135
150
158
165
TIME SPENT FISHING (HOURS)
1,440
3,240
3,600
3,792
3,960
TIME PER FISHING TRIP (HOURS)
12
32
36
42
53
NUMBER OF TRIPS
120
101
100
90
75
LANDINGS PER TRIP
313
926
1128
1667
5000
ACTUAL LANDINGS PER VESSEL.
$37,560
$93,526
$112,800
$150,030
$375,000
NUMBER OF FISHING VESSELS
14
9
9
10
4
TOTAL LANDINGS FOR
$525,840 $841,734 $1,015,200 $1,500,300 $1,500,000 $5,383,074
MINNECOCK INLET FLEET
COST DATA
VARIABLE COSTS
COSTS PER DAY
FUEL AND OIL
$58
$137
$153
$188
$333
SUPPLIES
$17
$38
$47
$63
$167
TOTAL VARIABLE COSTS PER DAY
$75
$175
$200
$250
$500
ACTUAL DAYS FISHING
120
135
150
158
165
ANNUAL VARIABLE COSTS PER
$9,000
$23,625
$30,000
$39,375
$82,500
VESSEL
ANNUAL WAGES (40% OF ACTUAL
$15,024
$37,410
$45,120
$60,012
$150,000
LANDINGS PER VESSEL)
ANNUAL FIXED COSTS
INSURANCE
$3,000
$4,000
$5,000
$8,000
$15,000
DEPRECIATION
$2,500
$6,250
$7,500
$10,000
$25,000
MAINTENANCE AND REPAIRS
$2,000
$5,000
$6,000
$8,000
$20,000
MOORAGE
$450
$550
$650
$750
$1,275
TOTAL ANNUAL FIXED COSTS
$7,950
$15,800
$19,150
$26,750
$61,275
TAL ANNUAL COSTS PER VESSEL
$31,974
$76,835
$94,270
$126,137
$293,775
E13
TABLE 7
SHINNECOCK INLET
POTENTIAL FOR INCREASED CATCH FOR VARIOUS FISHERIES
a
b
e
d
e
&
g
h
c=a/b
e=c x d
f=e/d
h=f X 9
FISH
NMFS
NMFS
FACTOR
1984
POTENTIAL
POTENTIAL
ESTIMATE ESTIMATE FOR
CATCH
SUFFOLK
SUFFOLK
OF
OF
POTENTIALFOR
COUNTY
COUNTY
1984
POTENTIAL1984
GROWTH
SUFFOLK
CATCH
CATCH
shinnecock
CATCH
CATCH
COUNTY
GROWTH
INLET
POTENTIAL
(METRIC
(METRIC
$
FACTOR
CATCH
CATCH
TONS)
TONS)
COD, ATLANTIC
10
12.2
0.8
$349,042
$286,100
FLOUNDER,ATLANTIC, BLACKBACK(WINTER) UNKNOWN
14.7
1.0
$156,795
$156,795
FLOUNDER,ATLANTIC, FLUKE (SUMMER)
17.5
14.2
1.2
$742,305
$914,813
FLOUNDER,ATLANTIC, YELLOWTAIL
16
5.8
2.8
$1,524,810
$4,206,372
SCUP
10.6
10.6
1.0
$266,384
$266,384
STRIPED BASS
0
$309,621
$0
LOBSTER, AMERICAN
7800
3900
2.0
$116,600
$233,200
SQUID, LONG FINNED
44
22.4
2.0
$738,535 $1,450,694
TOTAL
$4,204,092 $7,514,358
1.79 $4,600,000 $8,222,000
E14
value of the 1984 catch. Therefore, the potential
sustainable fish catch for Shinnecock Inlet is approximately
$8,200,000. Under without project conditions, the landings
are well within the estimated sustainable yield.
Without Project Condition -Under future without project
conditions, Shinnecock Inlet will become unusable by the base
year (1991) Based on interviews with present users, the
condition of Shinnecock Inlet has been continually
deteriorating.
Because conditions are so dangerous in Shinnecock Inlet,
vessel owners and captains of the largest fishing vessels are
planning on moving out of Shinnecock Inlet. If nothing is
done to improve the inlet, the most probable future condition
will eliminate the great majority of the current commercial
fleet. By 1991 the slot will become too narrow for vessel
use. Coastal and navigational analysis indicates that by
1991 the inlet will deteriorate to such a degree that deep
mean low water will equal 8 feet, and the narrowness of the
slot will prohibit vessel use. Fishing vessels except the
smallest will not be able to fish from Shinnecock Inlet.
The majority of the commercial fleet will relocate to other
ports.
All potential ports were given consideration in the
following analysis. Moriches Inlet is anticipated to be an
improved project site by the base year condition for the
Shinnecock Inlet analysis. Moriches, the closest south shore
port was determined to be viable for the smallest fishing
vessels. These vessels have drafts of approximately 5 feet.
The vessels are capable of using the Intercoastal Waterway
and leaving for ocean fishing through Moriches Inlet. These
smaller vessels (usually under 50 feet long) do not make
multi-day trips, since they are not as seaworthy as the
larger vessels. The additional time spent traveling through
the Intercoastal Waterway therefore, reduces the time the
vessel spends fishing, and in turn the vessels' landings. It
was estimated that the smaller commercial fishing vessels
would spend an additional 6 hours traveling through the
Intercoastal Waterway. This analysis is shown on Table 7.
Since the larger commercial vessels cannot navigate the
inland waterway other alternative ports were evaluated.
Moriches Inlet was not viable for the entire relocation
of the remaining 32 vessels in the fleet. Neither dock space
for the fleet nor commercial facilities for the catch are
available. Other ports in Nassau County were also excluded
E15
as potential alternatives. Currently Nassau County has
minimal room for additional large fishing vessels. In
addition, historically the fleets out of Nassau County have
not fished in NMFS area 613. Its present fleet does all
fishing in nearby areas with sufficient harvest.
In evaluating ports to the east of Shinnecock Inlet,
Montauk, located approximately 30 miles east of Shinnecock
was considered as an alternative port. However, Montauk's
docking facilities are currently filled to capacity primarily
with recreational boats. The port could not harbor the large
commercial fleet from Shinnecock.
It should be noted that the constraints identified for
the above ports are not limited to dockage but perhaps more
significant limited to commercial fishery facilities that
provide adequate storage, refrigeration and distribution
equipment. To allow Shinnecock Inlet to function as a vital
commercial port approximately 5.5 million dollars were
invested in the port to enable the docks and facilities to
serve the size of the existing fleet.
The most likely alternative port in Suffolk County for
the Shinnecock fleet is Greenport. Greenport is located
approximately 60 miles from Shinnecock Inlet- or approximately
6. hours by water for a commercial fishing vessel.
Historically a fleet did operate out of Greenport, however,
the fleet has decreased over the years as vessels left to
operate out of more profitable locations. Currently
Greenport has dock space available and the appropriate
facilities to service a large commercial fleet. Dockmasters
at Greenport were contacted and strongly indicated their
willingness and ability to assume the Shinnecock fleet. Even
in light of the fact that travel time to fishing sites would
increase by 12 hours per trip (6 hours one way from
Shinnecock fishing grounds to Greenport) Greenport was
determined to be the most probable alternative port.
Table 8, 9 and 10 show the most probable without project
conditions for landings, annual costs and net income.
Actual vessel operating data, and projected usage is based on
extensive interviews with fishermen and dock operators.
The National Marine Fishermen Service data on fishing vessel
operations, including the costs of various items, were
checked to confirm the interview data.
E16
TABLE 8
SHINNECOCK INLET
LANDINGS USING ALTERNATIVE PORTS
(WITHOUT PROJECT CONDITION)
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+ TOTALS
ALTERNATIVE PORT
MORICHES GREENPORT GREENPORT GREENPORT GREENPORT
TIME PER TRIP USING SHINNECOCK
12
32
36
42
53
+
+
+
+
+
TRAVEL TIME IN HOURS BETWEEN
SHINNECOCK AND ALTERNATE PORT
6
12
12
12
12
=
=
=
=
=
TOTAL TIME PER TRIP USING
18
44
48
54
65
ALTERNATIVE PORT(HOURS)
NUMBER OF DAYS FISHING
160
180
200
210
220
TIME SPENT FISHING(HOURS)
1920
4320
4800
5040
5280
/
/
/
/
/
TOTAL TIME PER TRIP USING
18
44
48
54
65
ALTERNATIVE PORT(HOURS)
=
=
=
=
=
TOTAL NUMBER OF TRIPS
107
98
100
93
81
X
X
X
X
X
LANDINGS PER TRIP
313
926
1128
1667
5000
II
=
=
=
=
TOTAL ANNUAL LANDINGS PER
$33,491
$90,748
$112,800
$155,031
$405,000
VESSEL USING ALTERNATIVE PORT
X
X
X
X
X
NUMBER OF FISHING VESSELS
14
9
9
10
4
ANNUAL LANDINGS USING
$468,874
$816,732 $1,015,200 $1,550,310 $1,620,000 $5,471,116
ALTERNATE PORT
E17
TABLE 9
SHINNECOCK INLET
CALCULATION OF ANNUAL COSTS UNDER WITHOUT
PROJECT AND WITH PROJECT CONDITIONS
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+
VARIABLE COSTS (BOTH WITHOUT PROJECT AND WITH PROJECT CONDITIONS)
COSTS PER DAY
FUEL AND OIL
$58
$137
$153
$188
$333
SUPPLIES
$17
$38
$47
$63
$167
TOTAL VARIABLE COSTS PER DAY
$75
$175
$200
$250
$500
NUMBER OF DAYS FISHING
160
180
200
210
220
ANNUAL VARIABLE COSTS
$12,000
$31,500
$40,000
$52,500
$110,000
PER VESSEL
TOTAL ANNUAL LANDINGS PER
$33,491
$90,748
$112,800
$155,031
$405,000
VESSEL USING ALTERNATIVE PORT
( WITHOUT PROJECT CONDITIONS)
ANNUAL WAGES (40% OF ACTUAL
LANDINGS PER VESSEL)
$13,396
$36,299
$45,120
$62,012
$162,000
ANNUAL FIXED COSTS
INSURANCE
$3,000
$4,000
$5,000
$8,000
$15,000
DEPRECIATION
$2,500
$6,250
$7,500
$10,000
$25,000
MAINTENANCE AND REPAIRS
$2,000
$5,000
$6,000
$8,000
$20,000
MOORAGE
$450
$550
$650
$750
$1,275
TOTAL ANNUAL FIXED COSTS
$7,950
$15,800
$19,150
$26,750
$61,275
ANNUAL VARIABLE COSTS
$12,000
$31,500
$40,000
$52,500
$110,000
ANNUAL WAGES
$13,396
$36,299
$45,120
$62,012
$162,000
ANNUAL FIXED COSTS
$7,950
$15,800
$19,150
$26,750
$61,275
TOTAL ANNUAL COSTS PER VESSEL
$33,346
$83,599
$104,270
$141,262
$333,275
X
X
X
x
X
NUMBER OF FISHING VESSELS
14
9
9
10
4
=
=
=
89
00
TOTAL ANNUAL COSTS FOR SIZE
$466,844
$752,391
$938,430
$1,412,620
$1,333,100
$4,903,385
CLASS
E18
TABLE 10
SHINNECOCK INLET
ANNUAL NET INCOME USING ALTERNATIVE PORT
(WITHOUT PROJECT CONDITION)
TOTALS
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+
ANNUAL LANDINGS USING
$468,874
$816,732 $1,015,200 $1,550,310 $1,620,000 $5,471,116
ALTERNATIVE PORT
TOTAL ANNUAL COSTS FOR SIZE
$466,844
$752,391
$938,430 $1,412,620 $1,333,100
$4,903,385
CLASS
=
=
=
=
=
=
ANNUAL NET INCOME USING
$2,030
$64,341
$76,770
$137,690
$286,900
$567,731
ALTERNATIVE PORT (WITHOUT
PROJECT CONDITION)
E19
Table 8 shows that the estimated landings equal
approximately $5.5 million for the present Shinnecock fleet
for Shinnecock Inlet without a plan of improvement. Table 8
indicates that the costs of operations for the fleet are
$4,900,000. It. should be noted that whether Shinnecock Inlet
is open or closed, the cost of operations for the fleet does
not change; the critical change will be the amount of
landings which determines the productivity of the fishing
operations.
Table 10, the net income using an alternative port, is
the difference between the annual landings in Table 8,
without project conditions, and, the annual costs in Table 9,
without project conditions. The net income for the present
fleet, under without project conditions (Shinnecock Inlet
closed), is estimated at $574,000.
With Project Conditions - The proposed plan of improvement is
a 10 foot mean low water channel with a width of 200 feet.
With 3 feet of high tide, the channel will have 13 feet of
available water. Based on interviews with fishermen and
experience at other ports, it was identified that the fishing
vessels operate on average, with 2 feet of clearance.
Fishing boats under 70 feet long, which in almost all
cases have drafts under 9 feet, will be able to enter and
leave with little regard to overloading or the tidal cycle.
Larger boats will continue to make use of the tide. The
larger vessels schedule themselves to leave and return on the
tide whenever necessary: Because the boats can fish close to
Shinnecock Inlet, the larger fishing vessels do not lose any
time fishing by waiting for the necessary amount of tide.
Tidal "delays" are not incurred by any of the vessels. With
a 10 foot channel all existing vessels except the 11.5 foot
draft vessel will operate out of Shinnecock Inlet. It is
projected that the 11.5 foot draft vessel would be replaced
by a shallower draft vessel that would continue to use
Shinnecock Inlet.
Table 11 shows landings for the existing fleet with the
plan of improvement. The time spent fishing has not changed.
The time spent fishing is more efficiently used; more trips
are made, and more tish are landed. Therefore, with a plan of
improvement, the existing fleet (with the 11.5 foot draft
vessel replaced) lands approximately $2,000,000 more fish or
a total of $7,175,000 shown in Table 11. Table 12 shows that
the net income for the existing fleet under with project
conditions equals approximately $2,267,000.
F20
TABLE 11
SHINNECOCK INLET
ANNUAL LANDINGS UNDER WITH PROJECT CONDITIONS FOR EXISTING FLEET
TOTALS
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+
NUMBER OF DAYS FISHING
160
180
200
210
220
NUMBER OF TRIPS
160
135
133
120
100
X
X
X
X
X
VESSEL LANDINGS PER TRIP
$313
$926
$1,128
$1,667
$5,000
=
II
"
=
=
ANNUAL LANDINGS PER VESSEL
$50,000
$125,000
$150,000
$200,000
$500,000
UNDER WITH PROJECT CONDITIONS
X
X
X
X
X
NUMBER OF FISHING VESSELS
14
9.
9
10
4
46
=
=
=
=
=
ANNUAL LANDINGS PER SIZE CLASS
UNDER WITH PROJECT CONDITIONS $700,000 $1,125,000 $1,350,000 $2,000,000 $2,000,000 $7,175,000
E21
TABLE 12
SHINNECOCK INLET
ANNUAL PROFITS WITH PROJECT CONDITIONS
FOR EXISTING FLEET
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+ TOTALS
ANNUAL LANDINGS PER SIZE CLASS
UNDER WITH PROJECT CONDITIONS $700,000 $1,125,000 $1,350,000 $2,000,000 $2,000,000 $7,175,000
TOTAL ANNUAL COSTS FOR SIZE
$466,844
$752,391
$938,430 $1,412,620 $1,333,100
$4,903,385
CLASS
=
=
=
=
=
=
ANNUAL NET PROFITS BY SIZE
$233,156
$372,609
$411,570
$587,380
$666,900
$2,271,615
CLASS (WITH PROJECT
CONDITIONS)
F22
Future Commercial Fishing Fleet - It is projected that under
with project conditions there would be two additional 80+
foot long fishing vessels with drafts of approximately 10
feet utilizing Shinnecock Inlet. The projection is based on
interviews with fishermen, the Fishermen's Cooperative and
other local interests and officials. Many fishermen have
indicated a desire to fish from Shinnecock Inlet. In 1985,
three 80+ foot long fishing vessels with drafts of
approximately 10 feet, came on line in Shinnecock Inlet.
The two additional commercial trawlers would have total
landings of approximately $1,000,000. This is based on the
data presented in Table 11, annual landings per vessel under
with project conditions for 80+ foot vessels. This would
increase total landings of the entire Shinnecock fleet to
approximately $8,200,000. With the projected fleet, the
inlet would reach the maximum sustainable yield. Table 13
shows the net income that would result from the additional
80+ foot fishing vessels.
Damage to Commercial Facilities - Under existing conditions,
erosion is destroying property on both sides of Shinnecock
Inlet. On the west side of Shinnecock Inlet there are
improved properties that consist of three major commercial
fishing and docking structures valued at approximately
$5,500,000. When erosion causes a breach in this area, the
facilities will be destroyed. Based on an existing erosion
rate of 3 acres per year, the facilities will be physically
destroyed in 1996. It is noted that the economic viability
of the commercial fishing facilities would end in 1991 the
baseyear of the project, since this is when the inlet would
be unnavigable. The vitality of the facilities is dependant
solely on a functioning inlet. Since some residual usage may
occur after 1991, the physical destruction of the facilities
was utilized in the analysis. The average annual damages
associated with this occurrence, $324,000, are shown on Table
13A.
Under with project conditions work is necessary in this
area to insure inlet stability. Since the improved condition
insures the existence of valuable commercial structures the
benefit for the prevention of damages to the commercial
facilities has been claimed. The existence of the commercial
facilities represent income generated from a functioning
inlet. The structure value of $5,500,000 is used as a proxy
for the income potential of the warehousing operations of
commercial fishing business. The structure value represents
E23
TABLE 13
SHINNECOCK INLET
NET INCOME WITH PROJECT CONDITIONS
FOR NEW FLEET
TOTALS
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+
ANNUAL NET PROFITS BY SIZE
$233,156
$372,609
$411,570
$587,380
$666,900
$2,271,615
CLASS (WITH PROJECT CONDITIONS)
/
/
/
/
/
NUMBER OF FISHING VESSELS
14
9
9
10
4
=
=
=
=
=
NET INCOME PER VESSEL
$16,654
$41,401
$45,730
$58,738
$166,725
X
X
X
X
X
PROFIT FROM NEW FISHING
0
0
0
0
2
VESSELS WITH PROJECT
=
=
=
=
=
PROFIT FROM NEW FISHING
$0
$0
$0
$0
$333,450
$333,450
VESSELS WITH PROJECT
E24
TABLE 13A
Shinnecock Inlet
Damage to Commercial Facilities
Value of Facilities
$5,500,000
Projected Year of Destruction
1996
Projected Year of Project Completion
1991
Number of years for present worth analysis
5
Project Life (Years)
50
Interest rate (decimal)
0.08875
Present worth factor
0.65367091
Present worth of damages in
1991
$3,595,000
Interest and Amortization factor
0.09003
Average Annual Damages
$324,000
E25
the minimum income potential of the facilities and is
therefore representative of a conservative income estimate.
These damages prevented under with project conditions were
included as a project benefit. The total average annual
benefits of $324,000 are included in the commercial fishing
benefits.
Benefit Analysis - Benefits are displayed in Table 14.
Benefits are the difference in net income between with
project conditions and without project conditions. Total net
income from the fishing fleet with the plan of improvement
is approximately $2,605,065, total net income from the
fishing fleet without the plan of improvement is
approximately $567,731. This commercial fishing benefit
equals approximately $2,037,334. Benefits from the
prevention of damage to the commercial facilities equal
$324,000.
Total commercial fishing benefits equal
approximately $2,361,300.
IV. Head Boat Evaluation
Head Boat Operating Characteristics - A head boat is a vessel
that goes on a regular schedule to fishing locations selected
by its captain. Each passenger on the boat is charged a
preset price. Head boats are usually large boats 40-90 feet
long that carry between 30 and 150 fishermen. Their drafts
are usually 6 feet and under. A head boat does not take
reservations. A head boat will advertise its schedule and
passengers go to the docks at the advertised appointed time.
A head boat cannot alter its schedule or make use of the
tidal cycle to mitigate for dangerous sea or inlet
conditions.
Historical Conditions - Fifteen years ago there were two head
boats operating out of Shinnecock Bay. They had few problems
using Shinnecock Inlet. Estimated income for these vessels
based on a recent study of a nearby operation is contained in
Table 15. In 1985, there was one head boat. The owner and
captain stated that the vessel was taken out of business
because Shinnecock Inlet was too dangerous to navigate. On
one occasion, the vessel suffered several thousand dollars
worth of damage when returning through Shinnecock Inlet due
to breaker action within the channel. The head boat went out
of business even though there was an active market and
experienced recreational fishermen have noted that the area
outside of Shinnecock Inlet is very good for fishing.
E26
TABLE 14
SHINNECOCK INLET
COMMERCIAL FISHING BENEFIT CALCULATION
TOTALS
VESSEL LENGTH
40-49
50-59
60-69
70-79
80+
ANNUAL NET PROFITS BY SIZE
$233,156
$372,609
$411,570
$587,380
$666,900
$2,271,615
CLASS (WITH PROJECT CONDITIONS)
-
-
-
-
-
-
ANNUAL NET INCOME USING
$2,030
$64,341
$76,770
$137,690
$286,900
$567,731
ALTERNATE PORTS (WITHOUT
PROJECT CONDITION)
BENEFITS FROM SHINNECOCK
$231,126
$308,268
$334,800
$449,690
$380,000
$1,703,884
PLAN OF IMPROVEMENT TO
EXISTING FLEET
+
PROFIT FROM NEW FISHING
$0
$0
$0
$0
$333,450
$333,450
VESSELS WITH PROJECT
BENEFITS TO COMMERCIAL FISHING
$2,037,334
UNDER PLAN OF IMPROVEMENT
BENEFITS FROM THE PREVENTION
$324,000
OF DAMAGE TO THE COMMERCIAL
FACILITIES
TOTAL BENEFITS TO COMMERCIAL
$2,361,334
FISHING UNDER PLAN OF
IMPROVEMENT
ROUNDED
$2,361,300
TABLE 15
SHINNECOCK INLET
PROJECTED INCOME FOR ATTRACTED
HEAD BOATS
(1986 PRICES)
WITH PROJECT
CHARACTERISTICS:
HEAD BOATS
Current value
$250,000
Number of days used
150
Number of trips
250
COST ($)
Variable cost (fuel, wages and supplies)
$51,900
Fixed costs (insurance, moorage and taxes)
$33,000
Depreciation
$25,300
Total cost
$110,200
Cost per day
$735
Cost per trip
$441
GROSS INCOME ($)
$261,375
Income per day
$1,743
Income per trip
$1,046
NET INCOME PER VESSEL
$151,175
Number of vessels if project is implemented
5
PROJECTED TOTAL NET INCOME
$755,875
SOURCE OF DATA: INTERVIEWS IN AREA, STUDIES OF HISTORICAL USAGE
AND COMPARATIVE STUDIES OF SIMILAR AREAS.
E28
Existing Head Boat Usage - At the present time there are no
head boats operating out of Shinnecock Bay.
Without Project Conditions - Under without project conditions
there will be no head boats in Shinnecock Bay because the
inlet will continue to be too dangerous to use.
With Project Conditions -Under the recommended plan of
improvement, Shinnecock Inlet will be a 10 foot mean low
water channel. An analysis was performed to confirm the
likelihood of head boats operating out of Shinnecock Inlet,
under a with project condition, considering the proximity of
other vital south shore ports. Moriches Inlet was reviewed
as a potential substitute for a Shinnecock Inlet fleet. The
evaluation indicated that head boats and charter boats are
not expected to operate from Moriches Inlet as a substitute
location for Shinnecock Inlet because Moriches Inlet is too
far away to serve the population centers around Shinnecock
Inlet. A analysis of vessel use shows that for the New
Jersey and New York Atlantic Coast, major head boat' and
charter boat docks are approximately 20 miles apart. Each
port has a different customer base. The significant demand
and vitality of the head and charter boat industry can be
illustrated by the following data:
E29
TABLE 16
MAJOR HEADBOAT AND CHARTER BOAT DOCKS
Distance from
Previous Ports
Inlet
Head Boats
Charter Boats
(Miles)
BARNEGAT N.J.
6
25
--
MANASQUAN N.J.
10
25
15
SHREWSBURY N.J.
12
20
20
ROCKAWAY L.I.
26
90
20
E. ROCKAWAY L.I.
40
50
10
JONES L.I.
12
40
10
FIRE ISLAND L.I.
14
50
20
MORICHES L.I.
(PROJECTED)
12
30
30
SHINNECOCK L.I.
-
45
15
MONTAUK L.I.
10
35
30
Therefore, it has been determined that Shinnecock Inlet
will have a separate and unique customer service base. This
is reflected in the economic analysis. Two head boats with
capacities similar to the historic fleet of Shinnecock Bay
can be expected to return. The head boats would return
because the dangerous conditions in Shinnecock Inlet would be
eliminated, and the demand for the vessels would exist.
Future Head Boat Fleet - An additional three head boats
are projected to come to Shinnecock Inlet under with project
conditions. Based on historical patterns and interviews with
marina operators and local officials, there is sufficient
parking and dock space for a total of five head boats.
Marina operators confirmed that they could provide necessary
physical capacity relating to berthing, parking and other
E30
requisite services for five head boats. These five head
boats would have a total net income of approximately $755,900
per year as displayed in Table 15.
Benefit Analysis - Benefits are the difference between the
net income under with project conditions and the net income
under without project conditions. The total net income
generated by the projected local head boat fleet equals
approximately $755,900.
V. Charter Boats Evaluation
Charter Boat Operating Characteristics - Charter boats are
usually cabin cruisers between 25 and 40 feet long which can
carry a maximum of 6 passengers. They have professional
captains. Drafts are under 5 feet. Vessel drafts do not
affect the operation through Shinnecock Inlet.
In
Shinnecock, these vessels are part time boats. During the
time the vessels are not used commercially, they are used by
their owners for private fishing. Under calm conditions in
Shinnecock Inlet, charter boats go out without difficulty.
Under normal conditions, the two lines of breakers across the
inlet create a slot through which the vessels currently
navigate. When the slot is wide enough, charter boats
captains have the ability to navigate without difficulty.
When the slot is narrow and meandering, the channel becomes
extremely treacherous. Charter boat captains have expert
knowledge, and can safely navigate the inlet under
conditions that would be dangerous and prohibitive for most
recreational boaters. When the risks become excessive,
however, they do not go through the inlet. They, like the
commercial fishermen discussed earlier, lose trips on
occasion because the inlet is too dangerous to navigate while
the sea outside is suitable for navigation.
Existing Charter Boat Usage - At present, there are
approximately 45 charter deep sea fishing boats that use
Shinnecock Inlet on a regular basis. The vessels average 50
ocean trips per year for a total of 2,250 trips per year for
the existing fleet. Net income is $506,700 under existing
conditions. Calculations are displayed in Table 17.
Without Project Conditions - Under without project
conditions, under normal sea conditions, breakers in the
inlet would be very severe and the narrowness of the inlet
would make the inlet unnavigable. Under the without project
condition, charter boats could not operate profitably.
Because adverse conditions occur approximately 35% of the
E31
TABLE 17
CHANGE IN CHARTER VESSEL INCOME IN
SHINNECOCK INLET UNDER VARIOUS ALTERNATIVES
EXISTING AND WITH PROJECT CONDITIONS
WITHOUT PROJECT CONDITIONS
PRICE
NUMBER
NUMBER
PER
OF
TOTALS
OF OCEAN
TRIP
TRIPS
TRIPS
INCOME
REVENUE
$500
2252
$1,126,000
173
$86,500
VARIABLE COSTS
$162
2252 $364,824
173 $28,026
(WAGES, FUEL AND SUPPLIES)
FIXED COSTS
$113
2252 $254,476
173 $254,476
(DEPRECIATION, MOORAGE
TAXES AND INSURANCE)
TOTAL COSTS
$275
2252
$619,300
173
$282,502
NET INCOME
$225
$506,700
($196,002)
SOURCES OF DATA:
NUMBER OF TRIPS AND PRICE PER TRIP FROM INTERVIEWS
COST DATA FROM VARIOUS CORPS' STUDIES
E32
time during the normal boating season, only 65% of the time
is available for trips, (60% normal conditions, 5% calm
conditions). Because the charter boats could only operate
during calm sea conditions, they could only make use of
approximately 5% of the boating season. Vessels usage would
be reduced to approximately 8% of the current usage,
(.05/.65), or approximately 173 trips (7.7% of 2,250). The
fixed costs for the boats would not change. Table 18
demonstrates that under the without project conditions, fixed
costs are greater than revenues and income is negative.
Vessel owners could not operate at a loss and therefore would
go out of business.
The charter boat business was reviewed to determine if
the owners could alter their operating procedures to maintain
a profitable business. The number of trips. used in the
analysis 2,250 corresponds to ocean trips (deep sea fishing).
Boat owners and marinas were contacted to determine the
likelihood of vessels operating in the bay. It was
determined that the demand for charter boat usage within the
bay is so minimal it was not an economically rational
alternative. In fact it was noted that demand for bay trips
was so minimal they would not even serve as a viable
supplement to the reduced number of ocean trips under without
project conditions.
With Project Conditions -Under with project conditions, the
charter boats will have no difficulty going through
Shinnecock Inlet to the ocean under calm or normal
conditions.
Future Charter Boat Fleet - The future charter boat fleet is
expected to be the same size as the present fleet under with
project conditions. Demand for boating is increasing
slightly and marina facilities are being maintained.
Shinnecock Bay shoreline is fairly well developed, however
therefore significant increases in the charter boat fleet are
not projected in this study.
Benefit Analysis - Benefits are the difference in net income
between the with project conditions and without project
conditions or approximately $506,700 per year. It is equal
to the losses that would be incurred, if the charter vessels
discontinue their business in the inlet.
E33
VI. Recreational Boating Evaluation
Existing Recreational Boat Usage - Data was collected to
identify and quantify the recreational deep sea fishing in
the inlet. Twenty five marinas were interviewed and reported
they docked approximately 2,000 recreational boats. Based on
1985 observations, approximately 700 vessels regularly go
through the inlet approximately 45 times per year, for a
total of 31,500 boat trips per year for ocean fishing. Each
boat averages slightly less than 5 people per trip so that a
total of 151,830 trips are made through the inlet each year.
Virtually all the boats going through the inlet go for
the primary purpose of deep sea fishing. This is a
specialized type of recreation. It requires significant
skill, the opportunities of use in general are limited and
the frequency of use is low.
Almost all of recreational vessels have drafts under 5
feet. Under existing conditions, the vessels occasionally,
refrain from going through Shinnecock Inlet because of the
breaker condition previously described. Vessels are not
constrained based on their draft. Under calm sea conditions,
recreational boats go over the sand bars because there are no
breakers and no need to utilize the deeper slot. Under
normal conditions, there are breakers, but the narrow slot
between the breakers is currently utilized by the
recreational boats. The boat captains are pleasure boaters
and attempt to minimize the risks in the inlet. They have
limited local knowledge and limited abilities. The boat
captains aim to use the deeper water in the channel to
minimize risks to the vessel.
Without Project Conditions - Under the without project
conditions, breakers will completely encroach across the
inlet and the channel will narrow significantly. In 1991
(the base year) the inlet will be approximately 8 feet deep
mean low water. However, again it is noted that depth is not
the constraining factor. The severe encroachment of the
breaker line and the narrowness and meandering of the channel
are the elements prohibiting use of the inlet. Under calm
conditions, the inlet is safe for recreational boats.
However, as discussed earlier, calm conditions exist
approximately five percent of the boating season. It is
apparent that this is insufficient time to justify the
E34
docking of vessels that are primarily interested in deep sea
fishing. The element of risk also becomes a factor in inlet
use, in that, a trip may be undertaken by a vessel during
calm conditions and yet, the condition may not be calm when
the boat returns. Therefore, due to the minimal navigable
time available for deep sea fishing and the uncertainty
involved, the without project conditions would prohibit all
recreational boats from navigating Shinnecock Inlet. Those
boats interested in deep sea fishing would either find new
berths at Montauk Point, a likely recreational choice, or
displace current general recreation boaters at Montauk Point.
Recreational deep sea fishing vessels could displace general
recreation boats because the deep sea fishermen are preferred
customers, generating more income to the docks. Specialized
deep sea fishermen buy more fuel and supplies, incur higher
costs for dock space, and use other marina services more
heavily than general recreational boats.
Shinnecock Inlet users that are forced to use Montauk
Point would incur increased costs under the without project
condition. These costs consist of travel expenses. The two
components of increased travel costs are mileage and time.
The mileage cost of approximately $756,000 is the cost
boaters would incur utilizing their cars to go from
Shinnecock Inlet to Montauk Point. Based on marina operators
observations, there is an average of 2 cars per recreational
vessel. The distance is 30 miles each way or 60 miles round
trip. The government approved rate for car costs is $.20 per
mile. The calculation of mileage cost is shown on Table 18.
Time cost of approximately $683,200, the value of
recreational time lost travelling, is also calculated on
Table 19. A proposed formula suggested in the Water Resource
Council's Principles and Guidelines to quantify leisure time,
is the use of one-third the average wage rate for adults.
One third of the estimated prevailing wage rate of Suffolk
County, or $3.00 per hour, was utilized in the analysis.
Increased travel costs from using Montauk Point totals
approximately $1,439,200 per year. Estimates of actual
numbers, based on interviews with marina operators, are used
in Table 18.
As a sensitivity test, the possibility that the
recreational boats could go through an improved Moriches
Inlet under without project conditions was analyzed. The
results of that analysis indicated it is a more expensive
alternative as displayed in Table 19. The vast majority,
over 90%, of the present recreational boats going through
E35
TABLE 18
SHINNECOCK INLET
INCREASED COSTS BY USING MONTAUK MARINAS
MILEAGE
number
round
cost
total
of
trip
per
mileage
CARS
MILES
X mile
costs
63,000
60
$0.20
$756,000
Round
trip
TIME COST
number
Travel
Cost
total
of
time
per
time
people
(Hours)
hour
cost
151,830
1.5
$3.00
$683,235
TOTAL TRAVEL COST
total
total
INCREASED
mileage
time
=
TRAVEL
costs
cost
COSTS
$756,000
$683,235
$1,439,235
MILEAGE, NUMBER OF CARS, NUMBER OF PEOPLE, MILEAGE
COST, TRAVEL TIME AND COST PER HOUR ARE BASED ON
ACTUAL PRESENT CONDITIONS WHICH ARE NOT EXPECTED TO
CHANGE. COST PER HOUR IS ABOUT ONE THIRD OF THE PREVAILING WAGE
RATE FOR SUFFOLK COUNTY.
E36
TABLE 19
SHINNECOCK INLET
INCREASED COSTS BY GOING THROUGH MORICHES INLET
number
fuel
MILEAGE
of
round
cost
total
boat
trip
per
mileage
trips
MILES
mile
costs
31,500 X
32 x
$0.30 = $302,400
Round
trip
TIME COST
number
Travel
Cost
total
of
time
per
time
people
(Hours)
hour
cost
151,830 X
4 X
$3.00 =$1,821,960
TOTAL TRAVEL COST
total
total
INCREASED
mileage
time
TRAVEL
costs
cost
COSTS
$302,400 + $1,821,960
=
$2,124,360
MILEAGE, NUMBER OF BOATS, NUMBER OF PEOPLE, MILEAGE
COST, TRAVEL TIME AND COST PER HOUR ARE BASED ON
ACTUAL PRESENT CONDITIONS WHICH ARE NOT EXPECTED TO
CHANGE. COST PER HOUR IS ABOUT ONE THIRD OF THE PREVAILING WAGE
RATE FOR SUFFOLK COUNTY.
E37
Shinnecock Inlet originate east of the Ponquogue Bridge. The
distance from Ponquogue Bridge to Moriches Inlet is
approximately 16 miles or 2 hours of travel time through
Shinnecock Bay and Moriches Bay, for a round trip total of 4
hours. The 4 hours represents the additional time recreators
would spend traveling to the fishing site. The value of
$3.00 per hour (detailed above) was used to quantify the cost
of time.
Based on the size of the boats going through Shinnecock
Inlet, an average of less than 3 miles per gallon was
determined. Fuel costs are approximately $.90 per gallon,
therefore fuel costs are $.30 per mile. Increased travel
costs using Moriches Inlet for boats based in Shinnecock Bay
approaches $2,124,400 per year. Operating out of Montauk,
with costs of $1,439,200 per year, is the least costly
alternative. Therefore, recreational operation out of
Montauk is used in this analysis of without project
conditions.
With Project Conditions - Under the with project conditions,
specialized recreational boats would have no problem going
through Shinnecock Inlet under calm and normal conditions.
The recreational vessels will have no reason to relocate out
of the Shinnecock Inlet area.
Future Recreational Fleet - The future specialized
recreational fleet is expected to maintain its size under
with project conditions. The demand for recreational boating
is increasing slightly according to the New York State
Comprehensive Outdoor Recreation Plan. Marina facilities are
being maintained and most of the Shinnecock area is well
developed.
In many shore front areas, marinas have been taken over
and replaced with high density waterside residential
development. However, the marina facilities at Shinnecock
are being maintained due to strong local support and the Town
of Southampton's Planning Board policies. Southampton zoning
regulations prevent marinas from being replaced with
waterside development or any other non-water related
construction. Increases over existing recreational boating
are not projected in this analysis, however, because the
Shinnecock Bay shoreline is well developed, and, room for
new sizable marinas is minimal.
Benefit Analysis - Benefits are the difference between costs
incurred under the with project conditions and those incurred
E38
in the without project conditions. Benefits accrued by
specialized recreational fishing vessels are the avoided
increased travel costs which would be incurred by traveling
to Montauk Point. The increased travel costs associated with
the movement of all specialized recreational fishing is
approximately $1,439,200 annually.
VII. Benefit Summary
Benefit Summary - Total annual benefits for the recommended
plan of improvement at Shinnecock Inlet are estimated at
$5,063,100 per year. Benefits for the proposed plan of
improvement include those from commercial fishing, income due
to head boats, income from charter boats, and cost savings to
recreational deep sea fishing vessels. They are summarized
in Table 20. Annual costs are $3,480,500 per year. The
benefits to cost ratio is 1.5, using a project interest rate
of 8 7/8% Net benefits for the recommended plan of
improvement are $1,582,600.
E39
TABLE 20
SHINNECOCK INLET
SUMMARIZATION OF BENEFITS
PROJECT INTEREST RATE
8.875 %
50 YEAR LIFE,
1986 PRICE LEVEL
1991 BASE YEAR
BENEFIT CATEGORY
AMOUNT
COMMERCIAL FISHING
$2,361,300
HEAD BOATS
$755,900
CHARTER BOATS
$506,700
RECREATIONAL DEEP SEA FISHING
$1,439,200
TOTAL BENEFITS
$5,063,100
/
ANNUAL COSTS
$3,480,500
=
BENEFIT COST RATIO
1.5
E40
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39
30-71
399-
APPENDIX F
Fish and Wildlife Resource Inventory
FISH AND WILDLIFE RESOURCE INVENTORY
FOR
SHINNECOCK INLET, SUFFOLK COUNTY, NEW YORK
-FINAL-
U.S ARMY CORPS OF ENGINEERS
NEW YORK DISTRICT
April 1985
I. INTRODUCTION.
Shinnecock Inlet is the easternmost of five inlets through the barrier
beach system that extends along the south shore of Long Island, New York. It
is located in the Town of Southampton, Suffolk County, 95 miles by water east
of the Battery, New York City and 37 miles west of Montauk Point. Tiana
Beach, a commercial fishery facility, two marinas and several restaurants lie
on the west side of the inlet; Southampton Beach and scattered houses lie on
the east side. The Tiana Beach area is part of Shinnecock West County Park;
Shinnecock East County Park is part of the study area on the east side of the
inlet. The inlet is bordered on the south area by the Atlantic Ocean and on
the north by Shinnecock Bay.
Records of Long Island from the colonial period on note the occasional
presence of natural openings through the barrier beach to Shinnecock Bay.
Openings are known to have been present in 1770, 1829 and 1850-1890. The
present opening of Shinnecock Inlet occurred as a result of wave action and
extreme high tides caused by the hurricane of 21 September 1938.
The inlet is approximately 1,500 feet long and 800 feet wide. A sandbar
exposed at low water is located just north of the inlet, with navigable
channels on its east and west sides. A second sandbar is located oceanward of
the inlet. Tidal range in the inlet is 2.9 feet. The spring tide is 3.5
feet; the neap tide range is 2.1 feet. Mean tidal range in the bay is 0.7
feet.
Shinnecock Bay is a shallow, bar-built estuary about 9 miles long, with
widths ranging up to 2.8 miles and a total water surface area of about 16
square miles. It drains about 20. square miles of land area, extending from
the Village of Southampton on the east to the Village of Quogue on the west.
On the north side the Bay is connected to Great Peconic Bay through Shinnecock
Canal. On the west, Quogue Canal and Quantuck Canal connect Shinnecock Bay
with Moriches Bay. Twenty drainage basins and streams enter the bay. The Bay
is divided into east and west sections by Ponquogue Point, a spit of land
which extends southward from the mainland at about the center of the bay and
connects the mainland with the barrier island via Ponquogue Bridge. Depths in
the Bay range from approximately 2-7 feet in the west section, and from
approximately 3-10 feet in the east section.
Water quality in Shinnecock Bay historically has been regulated by tidal
flushing through the inlet. Prior to the opening of the present inlet in
1938, seawater entered Shinnecock Bay through Shinnecock Canal from Great
Peconic Bay and through Quogue Canal from Moriches and Great South Bays.
During this period salinity was very low, except near Shinnecock Canal. Today
water quality in the study area is considered excellent. The New York State
Department of Environmental Conservation has classified the area as SA, or
suitable for shellfishing for market purposes and primary and secondary
contact recreation. This high water quality is largely due to the tremendous
flushing action that occurs through the inlet. Salinity data obtained by the
Suffolk County Department of Health Services indicate that salinity levels in
most of Shinnecock Bay are close to ocean levels.
The Long Island Intracoastal Waterway, a Federally authorized channel
completed in 1940, extends from the Great South Bay Channel to Shinnecock Bay,
providing a navigable channel 100 feet wide and 6 feet deep at Mean Low Water
for a distance of 33.6 miles. The waterway enters Shinnecock Bay via the
Quantuck and Quoque Canals, after entering Moriches Bay from Great South Bay
through Narrow Bay. In Shinnecock Bay the Intracoastal Waterway turns north
at a point just east of the Ponquoque Bridge to terminate at the southern end
of Shinnecock Canal.
Various navigational improvements have been constructed in the area of the
inlet since its formation. In 1943 the Corps of Engineers dredged a channel
in the Bay six feet deep and 100 feet wide from the north end of the inlet to
the Long Island Intracoastal Waterway. The most important work was
installation of stone revetments and jetties on either side of the inlet. The
jetties were built in 1952-1954; the revetments were constructed either before
the jetties (west side, in 1947) or at the same time as the jetties. The
total length of the east jetty at completion was 1,363 feet and the west jetty
was 946 feet.
The jetties, revetments and beaches on either side of the inlet have been
subjected to severe wave action from hurricanes and other storms. Shoaling of
the inlet has also become a problem, resulting in navigational hazards for
vessels using the inlet. In 1956 the Suffolk County Department of Highways
restored the dune on the east side of the inlet by placing 343,000 cubic yards
of sand on the eroded area. Most recently, the Corps of Engineers performed
an emergency dredging action in the project area in April 1984, which removed
approximately 162,000 cubic yards of sand from portions of the inlet, from a
shoal that extended approximately one-fourth mile southwest from the east
jetty, and from an offshore bar south of the inlet. The material was placed
in the surf zone of Tiana beach, adjacent to the west jetty, at the -7 ft.
contour. Considerable amounts of the deposited material subsequently washed
shoreward to extend the width of the beach in this area.
The authorized proposal currently under consideration by the Corps
provides for a 0.6 mile-long entrance channel 200 feet wide and 10 feet deep
at Mean Low Water from the Atlantic Ocean to Shinnecock Bay and thence a
channel to the Long Island Intracoastal Waterway 6 feet deep and 100 feet
wide; for rehabilitation of the existing stone jetties and revetments; for
seaward extension of the west jetty by 900 feet and extension of the east
jetty to the 12-foot contour. The plan also includes installation of a fixed
by-passing plant to transfer sand from the east side of the inlet to a feeder
beach on the west side, provided it is determined by further study that the
costs of sand transfer by means of such a plant would be lower than the costs
of operation of a proposed shallow-draft hopper dredge which would accomplish
the same results.
Several previous studies exist for parts or all of the Shinnecock Inlet
project area. For example, the Department of the Interior (USDOI), U.S. Fish
and Wildlife Service collected data on finfish and benthic fauna, terrestrial
fauna and terrestrial flora as part of fish and wildlife resource studies for
the Fire Island Inlet to Montauk Point, New York beach erosion control and
hurricane protection project reformulation study. The Suffolk County
Department of Public Works collected biological information as part of the
documentation prepared for the construction of the commercial fishery facility
2
at the inlet. Specific data on colonial waterbird colonies in the study area
were available through the Long Island tern survey being conducted by the New
York State Department of Environmental Conservation and Cornell University.
The information in this report has been compiled from these studies and other
reports relevant to the study area, personal communications with individuals
knowledgeable about the area and its resources, and field observations. One
complete, intensive study of the area is not available. However, with the
specific information known about the area and knowledge of what is likely to
occur in such an area, it has been possible to form a reasonably accurate
picture of area resources.
The EQ (Environmental Quality) Resources of the project area have been
identified as Shinnecock Inlet; portions of Shinnecock Bay; the nearshore
portions of the Atlantic Ocean; the barrier island; and the Warner Islands
with adjacent sandbar area, located north and northwest of the inlet. The
five areas were chosen because of the importance of their ecological and
aesthetic attributes.
II. MATERIALS AND METHODS.
Methods and sources for the preparation of this report were as follows:
Methods
Dates
Material Source
Literature Search
Mar. Sept. 1984
U.S Army Corps of Engineers, N.Y.
District library and files, New
York, New York
U.S. Fish and Wildlife Service
library, Long Island Sub Office,
Upton, New York
New York State Department of
Environmental Conservation
Long Island Regional Planning
Board, Hauppauge, New York
The Town of Southampton Planning
Board, Southampton, New York
Suffolk County Department of
Parks, Recreation and
Conservation, Southampton,
New York
Suffolk County Department of
Health Services, Water Quality
Unit
A list of references is included at the end of the report.
3
Persons Contacted
Philip Briggs
New York Department of Environmental Conservation
(NYSDEC), Finfish and Crustaceans
Thomas Hart
NYS Department of State, Coastal Zone Management
Program
Chet Zawicki
NYSDEC, Finfish and Crustaceans
Richard Fox
NYSDEC, Shellfisheries
Pieter Vanholkenburgh
NYSDEC, Shellfisheries
James Redman
NYSDEC, Shellfisheries
Warren Schlickenrieder
NYSDEC, Water Quality
Michael Scheibel
NYSDEC, Fish and Wildlife
Steven Sanford
NYSDEC, Fish and Wildlife
Lawrence Brown
NYSDEC, Significant Habitat Program
Robert Cerrato
State University of New York (SUNY), Marine
Science Research Center
Jay Tansky
SUNY, Marine Science Research Center
Bud Brinkhouse
SUNY, Marine Science Research Center
Gilbert Raynor
New York State Breeding Bird Atlas
Michael Ludwig
National Marine Fisheries Service
Estyn Mead
U.S. Fish and Wildlife Service
Paul Buckley
National Park Service
William Norton
National Park Service, Jamaica Bay Wildlife Refuge
Lawrence Little
Biology Dept., Southampton College of Long Island
University
J.R. Welker
Biology Dept., Southampton College of Long Island
University
A. Churchill
Biology Dept., Adelphi University
David Peterson
Seatuck Research Program, Laboratory of
Ornithology, Cornell University
Samuel Sadove
Research Director, Okeanos Ocean Research
Foundation
Robert Nuzzi
Suffolk County Department of Health Services,
Water Quality Unit
This report was prepared by:
Michele M. Farmer
B.A., Biology,
University of
Pennsylvania
M.S., Natural Resources
University of Michigan.
Four years with the U.S.
Army Corps of Engineers,
New York District
4
III. RESULTS.
The study area and project area, with EQ Resources identified, are shown
on Figure 1 and Figure 2.
A. Ecological Attributes.
Vegetation. Terrestrial vegetation in the project area consists of
typical plants of intertidal salt marsh, high salt marsh, and sand dunes in
the northeast.
Shinnecock Bay and its tributaries have approximately 637 acres of
wetlands, as designated by the Town of Southampton, and about 550 of these
acres are located on the south side of Shinnecock Bay. (Marine Science
Research Center, 1972). Approximately 175 acres of tidal wetlands are found
within the project area.
Detrital production from salt marshes is critical to the survival and
growth of several species of juvenile fish. Roots and rhizomes of marsh
vegetation are eaten by waterfowl and several species of birds nest in
marshes. In the project area salt marsh vegetation is found along the bay on
both sides of the inlet and on the Warner Islands within Shinnecock Bay
(Figure 3). Smooth cordgrass (Spartina alterniflora) dominates the intertidal
zone. Higher marsh areas contain a mixture of saltmarsh hay (Spartina
patens), salt grass (Distichlis spicata), glasswort (Salicornia spp.) common
reed (Phragmites australis), marsh-elder (Iva frutescens), and groundsel-tree
(Baccharis halimifolia).
Dune plants are less productive than the marsh plants. However, they
provide habitat for certain small mammals (see Mammals, p. ) and nesting
habitat for several bird species (see Birds, P. ). American beachgrass
(Ammophila breviligulata) and seaside goldenrod (Solidago sempervirens)
dominate the dunes of the study area. Northern bayberry (Myrica
pensylvanica), beach plum (Prunus maritima), poison ivy (Toxicodendron
radicans), false heather (Hudsonia tomentosa) sumac (Rhus sp.), groundsel-tree
(Baccharis halimifolia), salt-spray rose (Rosa rugosa) and various domestic
grasses occur in more limited amounts.
Aquatic macrophytes in the project area consist of eelgrass (Zostera
marina) and various species of algae. No eelgrass occurs in the immediate
area of the inlet. However, beds are located offshore of the marsh area west
of the inlet and may also exist in the vicinity of the Warner Islands and
marshes east of the inlet. Among other functions eelgrass provides food and
shelter for invertebrates, small fish and waterfowl, and acts as a source of
detritus.
Algae are found attached to the jetties and revetments, and pilings and
other structures associated with the commercial fishing facility and
marinas. Three species of rockweed (Fucus) have been identified in the rocky
intertidal habitat of the small "cove" that has formed behind the break at the
northern end of the east jetty: Fucus vesiculosus, F. edentatus and F.
distichus. These plants are not uncommon on the east coast--in fact, F.
vesiculosus is the most common and widespread species of rockweed on the
Atlantic coast-- but they are uncommon on the south shore of Long Island due
to the scarcity of rocky intertidal habitat.
5
SCALE 1:40,000
NAUTICAL MILES
Seborn
STATUTE MILES
VARDS
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2 $ / 1 /
I
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LATITUDE
LONGITUDE
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restricted only by the regulations
SA
Shinnecech inlet
PLANE COORDINATE GAID
1
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The depths through the into are -
New Vers Store Good. Long belowed sero
frequent
changes
and
1
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indicated by declared of 20 loss o
28
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SHINNECOTE
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SIMHONN
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36
Project area
Atlantic Ocean
30
Figure 1. Shinnecock Inlet study area, project area, EQ Resources.
CORPS OF ENGINEERS
DEPARTMENT OF THE ARMY
COAST
SHINNECOCK
BAY
GUARD
STATION
CONNECTICUT
NEW YORK
!
LONG IS SOUND
N.J.
ISLAND
LONG ISLAND
LONG
PROJECT DEPTH
PROJECT LOCATION
6 F1
.001
INLET
INL
OCEAN
10M.
0.3M
the
SHINNECOCK
ATLANTIC
VICINITY MAP
SCALE IN MILES
20
o
20
7
ROAD
PARK
JETTY
DUNE
COUNTY
- SHINNECOCK
JETTY
INLET
LEGEND
SHINNECOCK
PROJECT DEPTH
10 FT
NONE
WORK COMPLETED AS OF 30 SEPTEMBER 1983
200'
NONE
WORK PROPOSED WITH FUNDS AVAILABLE FOR FY 1984
NONE
WORK PROPOSED WITH FUNDS RECOMMENDED FOR FY 1985 #
00ML
WORK REQUIRED TO COMPLETE THE PROJECT AFTER
OCEAN
30 SEPTEMBER 1985
# PLANNING ONLY
ATLANTIC
SHINNECOCK INLET, N.Y.
PLAN
NEW YORK DISTRICT
SUFFOLK COUNTY
NORTH ATLANTIC DIVISION
SCALE IN FEET
181 CONGRESSIONAL DISTRICT
800
0
000
I JANUARY 1984
Figure 2. Shinnecock Inlet project.
N
Tuckahoe
II
14A
b
Shinnscock Hills
7
C
Hampton Bays
a
SHINNECOCK BAY
a
e
f
0
IMi
6A
1Km
Figure 3. Town of Southampton wetlands within project area (from Marine Science
Research Center, 1972).
8
Benthic fauna.
The most important commercial invertebrate species in the project area is
the surf clam (Spisula solidissima), found in the ocean from the surf zone to
depths as great as 250 feet. Lobsters (Homarus americanus) are also found in
the ocean portion of project area, in the vicinity of the two rock jetties.
Squid (Loligo pealei, (Ilex illecebrosus) and deep - sea scallop (Placopecten
magellanicus) are harvested commercially from deeper waters offshore, but
would not be expected to occur within the relatively shallow depths of the
project area.
The main part of Shinnecock Bay is open for shellfishing, and the bay
supports some commercial shellfish harvesting in addition to recreational
harvesting. However, the shellfish resources of Shinnecock Bay are considered
much less productive than those of Great South Bay or Moriches Bay, probably
due, at least in part, to the higher salinities of Shinnecock Bay. Hard clams
(Mercenaria mercenaria) are the most important commercial species harvested
within the bay. Limited quantities of soft-shelled clams, Mya arenaria; blue
mussels, Mytilus edulis (known beds within the project area are located in the
intertidal zone of marshes west of the inlet and in the vicinity of the Warner
Islands); razor clams, Ensis directus; and conches, Busycon spp., are also
marketed. Bay scallop (Aequipecten irradians) does not occur in any quantity.
The natural population of oysters (Crassostrea virginica) in Shinnecock
Bay is at present very low. Prior to the opening of the present Shinnecock
Inlet in 1938 there were also relatively few oysters, because the low salinity
levels of bay waters were not conducive to rapid oyster growth or fattening.
Oyster larvae which did manage to set survived well, however, because of the
absence of oyster drills. The opening of Shinnecock Inlet caused salinities
in the bay to increase, with consequent increases in the oyster population.
Oyster drill and Forbes seastar populations, favored by the higher bay
salinities, unfortunately also increased, and oyster populations in Shinnecock
Bay then declined. Today, the salinity level of the bay is at the upper limit
of the oyster's salinity tolerance levels. This and oyster drill/seastar
predation appear responsible in large part for the current low levels of the
wild oyster population (an apparently successful oyster cultivation operation
is being conducted by the Shinnecock Indians in Heady Creek).
Table 1 lists benthic species known or expected to occur within the project
area. Only organisms capable of adapting to constantly shifting sands will be
found within the inlet itself.
9
Table 1. Benthic fauna known or expected to occur within the Shinnecock Inlet
project area. 0 = Atlantic Ocean, B = Shinnecock Bay,
CLASS/SPECIES
COMMON NAME
TYPICAL HABITAT
NEMERTEA
Nemerteans (unidentified)
Nemerteans
B,O
NEMATODA
Nematodes (unidentified)
Nematodes
B,O
POLYCHAETA
Ampharete and related
genera
Ampharetid worms
0
Glycera spp.
Blood worms
B
Magelona riojai and
related spp.
Rosy magelonas
B
Nephtys spp.
Red-lined worms
B,O
Orbinia and related
genera
Orbiniid worms
B,O
Sthenelais and related
genera
Burrowing scale worms
B
Spio and related genera
Mud worms
B
Harmothoe spp.
Fifteen-scaled worms
B
Lepidonotus squamatus and
related genera
Twelve-scaled worms
B
Spirorbis and related
genera
Hard tube worms
B
Capitella capitata and
related spp.
Capitellid thread worms
B,O
Chaetozone and related
genera
Fringed worms
B
Goniadella and related spp.
Chevron worms
B,O
Ophelia and related spp.
Opheliid worms
B,O
Lumbrinereis spp.
Lumbrinerid thread worms
B,0
10
Table 1, continued
POLYCHAETA, cont.
Clymenella torquata and
related spp.
Bamboo worms
B
Spiochaetopterus oculatus
and related spp.
Parchment worms
B
Syllis and related genera
Syllid worms
B,O
Nereis spp.
Clam worms
B,O
Platyneris dumerilii
Dumeril's clam worm
B
Arabella iricolor
Opal worm
B,O
Diopatra cuprea
Plumed worm
B
GASTROPODA
Lunatia heros
Northern moon snail
B,O
Nassarius trivittatus and
related spp.
Mud snails
B
Cerithiopsis greeni
Green's cerith
B,O
Urosalpinx cinereus
Oyster drill
B
Eupleura caudata
Thick-lipped oyster drill
B
Busycon canaliculatum
Channeled whelk
3,0
Busycan carica
Knobbed whelk
B,O
Crepidula fornicata and
related spp.
Slipper shells
B,O
Littorina spp.
Periwinkles
B,O
BIVALVIA
Spisula solidissima
Surf clam
0
Tellina agilis
Dwarf tellin
B,O
Tellina versicolor
DeKay's dwarf tellin
B,O
Astarte castanea
Chestnut astarte
0
Lyonsia hyalina
Glassy lyonsia
B
Mytilus edulis
Blue mussel
B
Nucula proxima
Near nut shell
0
11
Table 1, continued
BIVALVIA cont.
Ensis directus
Razor clam
B,O
Corbula contracta
Common basket clam
B
Crassostrea virginica
Common oyster
B
Mya arenaria
Soft-shelled clam
B
Mercenaria mercenaria
Hard-shelled clam, quahog
B,O
Anomia sp.
Jingle shell
0
Gemma gemma
Gem shell
B,O
Modiolus demissus
Ribbed mussel
B,O
Macoma sp.
Macoma clam
B
CRUSTACEA
Crangon septemspinosus
Sand shrimp
B,0
Mysis and related
genera
Mysid shrimps
B,O
Caprella and related
genera
Skeleton shrimps
B,O
Palaemonetes spp.
Shore shrimps
B,O
Edotea and related
genera
Isopods
B,O
Calanus and related spp.
Copepods
B,O
Acanthohaustorius and
related genera
Amphipods
B,O
Oxyurostylis and related
genera
Peracarid crustaceans
B,0
Leptognatha caeca
Tanaid crustacean
B
Pagurus longicarpus and
related spp.
Hermit crabs
B,O
Ovalipes ocellatus
Lady crab
B,O
Cancer irroratus
Rock crab
B,0
12
Table 1, continued
CRUSTACEA, cont.
Cancer borealis
Jonah crab
B,O
Libinia emarginata
Common spider crab
B,O
Balanus spp.
Barnacles
B,O
Homarus americanus
American lobster
0
Callinectes sapidus
Blue crab
B,0
Carcinus maebas
Green crab
B,O
Neopanope and related
genera
Black-fingered mud crabs
B
Uca pugilator, U. pugnax
Fiddler crabs
B
Emerita talpoida
Mole crab
0
ARACHNIDA
Limulus polyphemus
Horseshoe crab
0
ASCIDIACEA
Molgula manhattensis and
related spp.
Tunicates
B,O
ASTEROIDEA
Asterias forbesi
Forbes seastar
B,O
ECHINOIDEA
Echinarachnius parma
Sand dollar
0
13
Finfish. Shinnecock Bay provides productive habitat for many fish
species. For example, fifty-one species of finfish were captured in
Shinnecock Bay by the U.S. Fish and Wildlife Service during the 1981 sampling
performed for the Corps of Engineers' Fire Island Inlet to Montauk Point, New
York, Beach Erosion Control and Hurricane Protection Project Reformulation
Study. The bay is considered a prime nursery area for winter flounder and
marsh areas east and west of the inlet provide shelter and feeding habitat for
juvenile bluefish (Pomatomus saltatrix), striped bass (Morone saxatilis) and
northern kingfish (Menticirrhus saxatilis).
The lack of significant aquatic vegetation in the inlet and ocean portions of
the project area suggest that these areas are used primarily for feeding
grounds rather than for shelter, with the exception of the immediate vicinity
of the jetties. The jetties provide feeding and/or shelter for such species
as tautog (Tautoga onitis), black sea bass (Centopristus striata) and cunner
(Tautogolabrus adspersus). The ocean portion of the project area is part of
the approximately 60 miles of barrier beach from Jones Inlet to Shinnecock
Inlet that provide some of New York's best surf fishing. Northern puffer
(Spheroides maculatus), striped bass, northern kingfish and bluefish are
commonly caught.
Table 2 lists fish species likely to be found in the study area on a
relatively conistent basis. Most species listed use the inlet for ingress or
egress and therefore can be found in the inlet itself on occasion, but would
be found more typically in the ocean or bay. Additional species, not listed,
can be found in the project area on an occasional or rare basis, as transients
or as a result of storms or abnormal water temperatures.
The Shinnecock Inlet area and ports of call reached through the inlet have
collectively developed into the largest commercial landing port in New York
State. Commercial fishing occurs primarily in the ocean. Recreational
fishing, however, is popular in both the bay and the ocean. In the study area
fishing occurs from boats, from the jetties on either side of the inlet, and
in the surf zone along the ocean side of the barrier beach.
14
Table 2. Finfish likely to occur in the Shinnecock Inlet study area on a
consistent basis. 0 = Atlantic Ocean, B = Shinnecock Bay.
Family Name/Common Name
Scientific Name
Habitat
ODONTASPIDIDAE - Sand tigers
Sand tiger
Odontaspis taurus
0
CARCHARHINIDAE - Requiem sharks
Sandbar shark
Carcharhinus milberti
0
Dusky shark
Carcharhinus obscurus
0
Smooth dogfish
Mustelus canis
B,0
Spiny dogfish
Squalus acanthias
0
RAJIDAE - Skates
Clearnose skate
Raja eglanteria
0
Barndoor skate
Raja laevis
0
Little skate
Raja erinacea
B,0
Winter skate
Raja ocellata
B,0
DASYATIDAE - Stingrays
Roughtail stingray
Dasyatis centroura
0
Atlantic stingray
Dasyatis sabina
0
ANGUILLIDAE - Freshwater eels
American eel
Anguilla rostrata
B,0
Conger eel
Conger oceanicus
B,O
CLUPEIDAE - Herrings
Atlantic menhaden
Brevoortia tyrannus
B,O
Blueback herring
Alosa aestivalis
B,0
Alewife
Alosa pseudoharengus
B,0
American shad
Alosa sapidissima
B,0
Round herring
Etrumerus teres
0
Atlantic herring
Clupea harengus
B,O
ENGRAULIDAE - Anchovies
Striped anchovy
Anchoa hepsetus
B,O
Bay anchovy
Anchoa mitchilli
B,0
SYNODONTIDAE - Lizardfishes
Inshore lizardfish
Synodus foetens
B
BATRACHOIDIDAE - Toadfishes
Oyster toadfish
Opsanus tau
B
LOPHIIDAE - Goosefishes
15
Table 2, continued
Goosefish
Lophius americanus
0
GADIDAE - Codfishes
Pollock
Pollachius virens
0
Silver hake
Merluccius bilinearis
B,O
Atlantic tomcod
Microgadus tomcod
B
Red hake
Urophycis chuss
B,0
White hake
Urophycis tenuis
B,O
OPHIDIIDAE - Cusk-eels
Striped cusk-eel
Ophidion marginatum
B
ZOARCIDAE - Eelpouts
Ocean pout
Macrozoarces americanus
0
BELONIDAE - Needlefishes
Atlantic needlefish
Strongylura marina
B
CYPRINODONTIDAE - Killifishes
Mummichog
Fundulus heteroclitus
B
Striped killifish
Fundulus majalis
B
Sheepshead minnow
Cyprinodon variegatus
B
ATHERINIDAE - Silversides
Atlantic silverside
Menidia menidia
B
Tidewater silverside
Menidia peninsulae
B
GASTEROSTEIDAE - Sticklebacks
Fourspine stickleback
Apeltes quadracus
B
Threespine stickleback
Gasterosteus aculeatus
B
Blackspotted stickleback
Gasterosteus wheatlandi
B
SYNGNATHIDAE - Pipefishes, seahorses
Northern pipefish
Syngnathus fuscus
B
Lined seahorse
Hippocampus erectus
B
PERCICHTHYIDAE - Temperate basses
Striped bass
Morone saxatilis
B,0
White perch
Morone americana
B
SERRANIDAE - Sea basses
Black sea bass
Centropristus striata
B,O
16
Table 2 continued
POMATOMIDAE - Bluefishes
Bluefish
Pomatomus saltatrix
B,O
CARANGIDAE - Jacks
Blue runner (rare regular)
Caranx crysos
B,0
Crevalle jack (rare regular)
Caranx hippos
B,0
Banded rudderfish
Seriola zonata
0
Mackerel scad (rare regular)
Decapterus macarellus
B,0
Bigeye scad (rare regular)
Selar crumenophthalmus
B,0
Rough scad (rare regular)
Trachurus lathami
B,0
SPARIDAE - Porgies
Scup (Porgy)
Stenotomus chrysops
B,0
SCIAENIDAE -Drums
Weakfish
Cynoscion regalis
B,O
Northern kingfish
Menticirrhus saxatilis
B,O
Silver perch
Bairdiella chrysoura
B
Spot
Leiostomus xanthurus
B
LABRIDAE - Wrasses
Tautog (blackfish)
Tautoga onitis
B,O
Cunner
Tautogolabrus adspersus
B,O
MUGILIDAE - Mullets
Striped mullet
Mugil cephalus
B,O
White mullet
Mugil curema
B,O
SPHYRAENIDAE - Barracudas
Northern sennet (rare regular)
Sphyraena borealis
B
BLENNIDAE - Combtooth blennies
Striped blenny
Chasmoda bosquiannus
B
Feather blenny
Hypsoblennius hentzi
B
PHOLIDAE - Gunnels
Rock gunnel
Pholis gunnellus
B,O
AMMODYTIDAE - Sand lances
American sand lance
Ammodytes americanus
B,0
GOBIIDAE = Gobies
Naked goby
Gobiosoma bosci
B
Seaboard goby
Gobiosoma ginsburgi
B
17
Table 2, continued
SCOMBRIDAE - Mackerels, tunas
Atlantic mackerel
Scomber scombrus
B,O
Atlantic bonito
Sarda sarda
0
STROMATEIDAE - Butterfishes
Butterfish
Peprilus triacanthus
B,O
TRIGLIDAE - Searobins
Northern searobin
Prionotus carolinus
B
Striped searobin
Prionotus evolans
B
COTTIDAE - Sculpins
Grubby
Myoxocephalus aenaeus
B
Longhorn sculpin
Myoxocephalus octodecemspinosus B
Shorthorn sculpin
Myoxocephalus scorpius
B
BOTHIDAE - Lefteye flounders
Summer flounder
Paralichthys dentatus
B,O
Fourspot flounder
Paralichthys oblongus
B,O
Windowpane flounder
Scophthalmus aquosus
B,O
Whiff
Citharichthys sp.
B
Smallmouth flounder
Etropus microstomus
B
PLEURONECTIDAE - Righteye flounders
Winter flounder
Pseudopleuronectes americanus
B,O
Yellowtail flounder
Limanda ferruginea
0
SOLEIDAE - Soles
Hogchoker
Trinectes maculatus
B
BALISTIDAE - Triggerfishes, filefishes
Planehead filefish
Monacanthus hispidus
0
Orange filefish
Aluterus schoepfi
0
Gray triggerfish
Balistes capriscus
0
TETRAODONTIDAE - Puffers
Northern puffer
Spheroides maculatus
B,O
18
Amphibians.
The only terrestrial amphibian species that has been recorded in the
vicinity of the project site is Fowler's toad (Bufo woodhousei fowleri)
(USDOI, 1983), the most common amphibian species along the south shore of Long
Island. This species appears to be fairly tolerant of occasional salt spray
or overwash. However, it does require the presence of at least ephemeral
fresh-water ponds for breeding purposes (USDOI, 1983). The scarcity of
ephemeral freshwater ponds in the vicinity of Shinnecock Inlet probably limits
its abundance in the area. Adult Fowler's toads, however, will be found in
the project area. No other amphibian species are likely to be present in the
project area, probably due to the lack of permanent freshwater ponds.
Reptiles.
The northern diamondback terrapin (Malaclemys terrapin terrapin) is the
only reptile likely to reside in the project area. Although no sightings of
northern diamondback terrapins are known from the area, the species does occur
in coastal marshes and inner edges of barrier beaches and is known to occur in
Shinnecock Bay (Bill Norton, Jamaica Bay Wildlife Refuge, pers. comm., March
1985). It may, therefore, very well be found in the wetlands east and west of
the inlet, on the bay side of the project area.
The Atlantic green sea turtle (Chelonia mydas), Atlantic hawksbill sea turtle
(Eretmochelys imbricata), Atlantic loggerhead sea turtle (Caretta caretta),
Atlantic Ridley sea turtle (Lepidochelys kempii) and Atlantic leatherback sea
turtle (Dermochelys coriacea) may also occur within the project area, but
would be present only as transients or accidental strandings.
Birds.
Shinnecock Bay is part of the Atlantic Flyway and, as such, is used by
over 25 species of migrating waterfowl. The greatest use of the project area
by migrating birds occurs during the fall migration, but hundreds of
waterbirds and shorebirds rest and feed in the project area during the winter
months as well. These species include black duck (Anas rubripes), mallard
(Anas platyrhynchos), gadwall (Anas strepera), canvasback (Aythya
valisineria), common goldeneye (Bucephala clangula), greater scaup (Aythya
marila), herring gull (Larus argentatus), Bonaparte's gull (Larus
philadelphia), blackheaded gull (Larus ridibundus), and northern gannet (Sula
bassanus) (Table 3). The intertidal flats and sandbar in the bay north and
west of the outlet are used by thousands of birds in the fall and winter for
feeding and resting. Most of the hawks, falcons, and harriers that migrate
through the project area and the wintering owls use the interdune and primary
back dune grasslands and swales for feeding habitat.
The immediate area of Shinnecock Inlet provides important feeding habitat
for many birds. Indeed, inlets are well known as focal points for
concentrations of marine shore birds. This generally has been attributed to
increased primary and secondary productivity of well-oxygenated inlet
waters. Buckley and Buckley (1980) hypothesized that the occurrence of large
colonies of terns at suitable, undeveloped inlets such as Jones, Fire Island,
Moriches, and, Shinnecock was directly related to the prey-fish productivity of
19
Table 3. Birds of the Shinnecock Inlet project area. PO = Possible Breeder; PR = Probable Breeder,
CO - Confirmed Breeder. A = Abundant, C = Common, U = Uncommon, R = Rare.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding
Migration
Wintering
Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Gavidae - Loons
Common Loon
Gavia immer
Ocean and Bays
X
X
C
C
R
C
Fall and Spring
Migrant.
Red- throated Loon
Gavia stellata
Ocean and Bays
X
X
C
C
C
Fall and spring
Migrant.
Podicipedidae - Grebes
Red- necked Grebe
Podiceps grisegena
Ocean
X
X
R
U
Winter Visitor.
Horned Grebe
Podiceps auritus
Ocean and Bays
X
X
C
U
C
Winter Resident.
Sulidae - Gannets and Boobies
Northern Gannet
Sula bassanus
Ocean
X
20
X
U
C
Winter Visitor.
Phalacroooracidae - Cormorants
Great Cormorant
Phalacrocorax carbo
Ocean and Bays
X
X
C
U
Winter Resident
Double- crested Cormorant
Phlacrocorax auritus
Ocean and Bays
X
R
C
C
A
Fall Migrant.
Ardeidae - Herons and Bitterns
Great Blue Heron
Ardea herodias
Salt Marsh
X
X
C
C
U
C
Summer Non- breeder;
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall Principal Occurrence
in the Project Area
Ardeidae - Herons and Bitterns, cont.
Green-backed Heron
Butorides striatus
Salt Marsh
X
c
C
Fall Migrant.
Great Egret
Casmerodius albus
Salt Marsh
X
C
C
.
Fall Migrant.
Snowy Egret
Egretta thula
Salt Marsh
X
C
C
Fall Migrant.
Black- crowned Night- Heron
Nycticorax nyctlcorax
Salt Marsh
X
C
C
Fall Migrant.
Threskiornithidae Ibises
Glossy Ibis
Plegadis falcinellus
Salt Marsh
X
C
C
Fall Migrant.
Anatidae - Waterfowl
Tundra Swan
21
Olor columbianus
Bays and Ponds
X
R
Winter Visitor.
Mute Swan
Bays, Estuaries,
Cygnus olor
Ponds, and Lakes
X
X
U
U
U
U
Resident.
Canada Goose
Branta canadensis
Bays and Ponds
X
X
A
C
U
A
Resident.
Atlantic Brant
Branta bernicla
Bays
X
X
C
C
C
Winter Resident.
Snow Goose
Chen caerulescens
Bays
X
U
Fall Migrant.
Mallard
Salt Marsh, Estuaries,
Anas platyrhynchos
and Bays
PR
X
X
C
C
C
C
Resident.
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding
Migration
Wintering
Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Anatidae - Waterfowl, cont.
Black Duck
Salt Marsh, Estuaries,
Anas rubripes
and Bays
X
X
A
C
U
A
Resident.
Gadwall
Anas strepera
Salt Marsh
X
X
C
U
U
A
Resident.
Pintail
Anas acuta
Salt Marsh
X
X
C
c
Winter Resident.
Green- winged Teal
Anas crecca
Salt Marsh
X
X
U
C
Fall Migrant.
Blue- winged Teal
Anas discors
Creeks and Ponds
X
U
R
Summer M igrant.
American Wigeon (Baldpate)
Anas americana
Salt Marsh and Bays
X
X
C
c
Winter Resident.
Northern Shoveler
Anas clypeata
Salt Marsh and Bays
X
X
U
U
22
Winter Resident.
Redhead
Aythya americana
Bays and Ponds
X
X
C
C
Winter Resident.
Ring- necked Duck
Aythya collaris
Large Ponds
X
X
U
U
U
Winter Resident.
Canvasback
Aythya valisineria
Bays and Ponds
X
X
C
U
Winter Resident.
Greater Scaup
Aythya marila
Bays
X
X
A
C
C
Winter Resident.
Common Goldeneye
Bucephala clangula
Bays
X
X
A
C
Winter Resident.
Table 3, cont.
Habitat Utilization
Family/Species
Seasonal Abundance
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Anatidae - Waterfowl, cont.
Bufflehead
Bucephala albeola
Bays
X
X
A
C
C
Winter Resident.
Oldsquaw
Clangula hyemalis
Ocean and Bays
X
X
A
C
C
Winter Resident.
Harlequin Duck
Histrionicus histrionicus
Ocean; Jetties
X
R
Winter Visitor.
Common Eider
Somateria mollissima
Ocean
X
U
Winter Visitor.
King Elder
Somateria spectabilis
Ocean
X
R
Winter Visitor.
White-winged Scoter
Melanitta deglandi
Ocean
X
X
A
C
A
Winter Resident.
Surf Scoter
Melanitta perspicillata
Ocean
X
X
C
C
C
Winter Resident.
23
Black Scoter
Melanitta nigra
Ocean
X
X
c
U
C
Winter Resident.
Ruddy Duck
Oxyura jamaicensis
Bays
X
X
C
C
C
Winter Resident.
Common Merganser
Mergus merganser
Lakes
X
X
R
U
Winter Visitor.
Red-breasted Merganser
Mergus serrator
Bays
X
X
A
C
C
Winter Resident.
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Accipitridae - Hawks, Eagles,
and Harriers
Sharp- shinned Hawk
Accipiter striatus
Barrier Beach
X
C
Fall Migrant.
Cooper's Hawk
Accipiter cooperii
Barrier Beach
X
R
Fall Migrant.
Red- tailed Hawk
Buteo jamaicensis
Deciduous Woods
X
U
U
U
Fall Migrant.
Rough- legged Hawk
Buteo lagopus
Barrier Beach
X
R
Winter Visitor.
Bald Eagle
Haliaeetus leucocephalus
Cosmopolitan
X
R
Winter Visitor.
Northern Harrier
Circus cyaneus
Barrier Beach
X
X
C
C
U
A
Fall Migrant.
Pandionidae - Ospreys
24
Osprey
Pandion haliaeetus
Bays, Ponds, and Creeks
X
R
U
Fall Migrant.
Falconidae - Falcon
Peregrine Falcon
Falco peregrinus
Barrier Beach
X
R
Fall Migrant.
Merlin
Falco columbarius
Barrier Beach
X
X
U
C
Fall Migrant
American Kestrel
Falco sparverius
Barrier Beach; Meadows
X
X
C
U
U
A
Resident.
Table 3, cont.
Habitat Utilization
Family/Species
Seasonal Abundance
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Phasianidae - Pheasants and Quail
Ring- necked Pheasant
Barrier Beach;
Phasianus colchicus
Old Fields
PO
X
C
C
C
C
Resident
Rallidae - Rails, Gallinules, and Coots
Clapper Rail
Rallus longirostris
Salt Marsh
X
U
R
U
Resident.
Virginia Rail
Salt and
Rallus limicola
Freshwater Marsh
X
X
R
R
R
R
Resident.
American Coot
Fulica americana
Estuaries and Ponds
X
C
Winter Resident.
Haematopodidae. Oystercatchers
American Oystercatcher
Haematopus palliatus
Salt Marsh
CO
X
U
C
C
Fall Migrant.
Charadriidae Plovers
25
Semipalmated Plover
Charadrius semipalmatus
Tidal Mud Flats
X
U
U
C
Fall Migrant.
Killdeer
Barrier Beach;
Charadrius vociferus
Old Fields
X
R
U
Fall Migrant.
Piping Plover
Charadrius melodus
Sandy Beach
CO
X
U
C
U
Fall Migrant.
Lesser Golden Plover
Charadrius dominica
Agricultural Fields
X
R
R
Fall and Spring
Black-bellied Plover
Migrant.
Pluvialis squatarola
Tidal Mud Flats
X
X
R
C
A
Fall and Spring
Migrant.
Table 3. cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding
Migration
Wintering
Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Scolopacidae - Sandpipers
Hudsonian Godwit
Limosa haemastica
Tidal Mud Flats
X
U
U
Fall and Spring
Marbled Godwit
Migrant.
Limosa fedoa
Tidal Mud Flats
X
R
U
Fall Migrant.
Whimbrel
Salt Marsh;
Numenius phaeopus
Tidal Mud Flats
X
U
U
Fall and Spring
Greater Yellowlegs
Salt Marsh;
Migrant.
Tringa melanoleuca
Tidal Mud Flats
X
X
R
C
A
Fall Migrant.
Lesser Yellowlegs
Salt Marsh;
Tringa flavipes
Tidal Mud Flats
X
C
A
Fall Migrant.
Solitary Sandpiper
Ponds;
Tringa solitaria
Freshwater Marshes
X
U
U
Fall and Spring
Willet
Migrant.
Catoptrophorus semipalmatus
Salt Marsh
CO
X
X
R
C
C
C
Resident.
Spotted Sandpiper
26
Actitis macularia
Ocean Beach
PO
X
U
U
Fall Migrant.
Ruddy Turnstone
Ocean Beach;
Arenaria interpres
Tidal Mud Flats'
X
C
R
C
Fall and Spring
Common Snipe
Tidal Mud Flats;
Migrant.
Capella galinago
Net Meadows and Fields
X
R
Fall Migrant.
Short-billed Dowitcher
Limnodromus griseus
Tidal Mud Flats
X
X
C
C
Fall and Spring
Migrant.
Long-billed Dowltcher
Limnodromus scolopaceus
Ponds; Tidal Mud Flats
X
R
R
Fall and Spring
Migrant.
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall Principal Occurrence
in the Project Area
Scolopacidae Sandpipers, cont.
Red Knot
Ocean Beach;
Calidris canutus
Tidal Mud Flats
X
R
U
C
Fall Migrant.
Sanderling
Ocean Beach;
Calidris alba
Tidal Mud Flats
X
X
U
C
A
Fall Migrant.
Semipalmated Sandpiper
Calidris pusilla
Tidal Mud Flats
X
C
A
Fall Migrant.
Western Sandpiper
Calidris mauri
Tidal Mud Flats
X
R
Fall Migrant.
Least Sandpiper
Calidris minutilla
Tidal Mud Flats
X
C
U
A
Fall Migrant.
White-rumped Sandpiper
Calidris fuscicollis
Tidal Mud Flats
X
R
R
Fall and Spring
Pectoral Sandpiper
Migrant.
27
Calidris melanotos
Tidal Mud Flats
X
U
C
Fall Migrant.
Purple Sandpiper
Calidris maritima
Rock Jetties; Inlets
X
C
Winter Resident.
Dunlin
Salt Marsh;
Calidris alpina
Tidal Mud Flats
X
X
R
C
A
Fall Migrant.
Stilt Sandpiper
Micropalama himantopus
Tidal Mud Flats
X
R
U
Fall Migrant.
Laridae - Gulls and Terns
Glaucous Gull
Larus hyperboreus
Bays: Inlets
X
R
Winter Visitor.
Table 3, cont.
Habital Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Laridae Gulls and Terns, cont.
Iceland Gull
Larus glaucoides
Ocean Beach
X
R
Winter Visitor.
Greater Black-backed Gull
Larus marinus
Ocean and Bays
X
C
C
C
C
Resident.
Lesser Black-backed Gull
Larus fuscus
Coastal: Ocean Beach
X
R
Winter Visitor.
Herring Gull
Larus argentatus
Ocean and Bays; Fields
X
C
C
C
c
Resident.
Ring-billed Gull
Ocean, Bays and
Larus delawarensis
Freshwater Ponds; Fields
X
X
U
C
U
C
Fall and Spring
Migrant.
Black-headed Gull
Larus ridibundus
Inlets
X
R
Winter Visitor.
Laughing Gull
larus artricilla
Coastal; Ocean Beach
X
R
C
C
Fall Migrant.
28
Bonaparte's Gull
Larus philadelphia
Bays and Inlets
X
A
C
Winter Visitor:
Little Gull
Larus minutus
Bays
X
R
Winter Visitor.
Black-legged Kittiwake
Rissa tridactyla
Ocean
X
R
Winter Visitor:
Especially Montauk
Point.
Common Tern
Bays; Islands;
Sterna hirundo
Salt Marsh
CO
X
U
A
C
Summer Breeder;
Migraned Spring
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall Principal Occurrence
in the Project Area
Laridae Gulls and Terns, cont.
Roseate Tern
Bays; Islands;
Sterna dougallii
Salt Marsh
CO X
R
R
R
Summer Breeder;
Fall and Spring
Migrant.
Least Tern
Sterna albifrons
Sandy Beach
CO X
U
C
U
Summer Breeder;
Fall and Spring
Migrant.
Royal Tern.
Sterna maxima
Inlets
X
R
Fall Migrant.
Caspian Tern
Sterna caspia
Inlets
X
R
Fall Migrant.
Rynchopidae Skimmers
Black Skimmer
Rynchops niger
Bays; Islands
X
X
C
C
Summer Breeder;
29
Alcidae - Auks
Fall Migrant.
Dovekie
Alle alle
Ocean; Inlets
X
R
Winter Visitor.
Columbidae - Pigeons and Doves
Mourning Dove
Barrier Beach;
Zenaidura macroura
Conifers
PO
X
X
C
C
C
A
Resident.
Tytonidae - Barn Owls
Barn Owl
Abandoned Buildings; Old
Tyto alba
Fields and Meadows
X
X
R
R
R
Fall and Spring
Migrant
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Strigidae - Typical Owls
Snowy Owl
Nyctea scandiaca
Barrier Beach
X
R
Winter Visitor
Short-eared Owl
Salt Marsh;
Asio flammeus
Barrier Beach
X
C
U
U
Winter Resident.
Saw-whet Owl
Aegolius acadicus
Barrier Beach
X
R
Winter Visitor.
Alcedinidae - Kingfishers
Belted Kingfisher
Sand Bluffs;
Megaceryle alcyon
Ponds and Creeks
X
X
R
U
C
C
Resident.
Picidae - Woodpeckers
Red-headed Woodpecker
Melanerpes erythrocephalus
Barrier Beach
X
R
U
Fall Migrant.
Common Flicker
Barrier Beach;
Colaptes auratus
Residential Areas
X
X
U
U
C
A
Resident.
30
Downy Woodpecker
Picoides pubescens
Woodlands
X
X
C
C
C
C
Resident.
Tyrannidae - Flycatchers
Eastern Kingbird
Scrub-Shrub Fields
Tyrannus tyrannus
and Meadows
PO
X
C
C
Fall and Spring
Migrant.
Eastern Phoebe
Bridges; Abandoned
Sayornis phoebe
Buildings; Residential
Areas
U
Summer Resident.
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Alaudidae Larks
Horned Lark
Eremophila alpestris
Barrier Beach
CO
X
X
C
C
U
C
Resident.
Hirundinidae - - Swallows
Tree Swallow
Iridoprocne bicolor
Sand Banks and Bluffs
X
C
C
Fall Migrant.
Bank Swallow
Riparia riparia
Sand Banks and Bluffs
X
C
C
Fall Migrant.
Rough-winged Swallow
Stelgidopteryx ruficollis
Sand Banks and Bluffs
X
U
U
Fall Migrant.
Barn Swallow
Abandoned Buildings;
Hirundo rustica
Residential Areas
CO X
C
A
Fall Migrant
Corvidae - Jays and Crows
Fish Crow
Corvus ossifragus
Barrier Beach; Bayshore
X
X
R
U
U
U
Resident.
31
Troglodytidae - Wrens
Winter Wren
Troglodytes troglodytes
Woodlands
X
R
Winter Resident.
Marsh Wren
Cistothrus palustris
Phragmites Marsh
U
Summer Resident.
Mimidae - Mimic Thrushes
Northern Mockingbird
Barrier Beach;
Mimus polyglottos
Residential Areas
PR
X
C
C
C
C
Resident.
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding
Migration
Wintering
Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Mimidae - Mimic Thrushes, cont.
Gray Catbird
Scrub-Shrub Fields
Dumetella carolinensis
and Meadows
PO
X
X
R
U
C
C
Resident.
Brown Thrasher
Interdune Woods
Toxostoma rufum
and Thickets
X
X
R
U
C
C
Resident.
Turdidae - Thrushes
American Robin
Turdus migratorius
Residential Areas
CO
X
X
C
C
C
C
Resident.
Laniidae - Shrikes
Loggerhead Shrike
Interdune Swale
Lanius ludovicianus
and Grasslands
X
R
R
Winter Visitor.
Sturnidae - Starlings
European Starling
Sturnus vulgaris
Residential Areas
PO
X
X
C
C
C
A
Resident.
32
Vireonidae - Vireos
Whte-eyed Vireo
Vireo griseus
Interdune Thickets
R
Summer Resident.
Parulidae - Wood Warblers
Orange-crowned Warbler
Vermivora celata
Barrier Beach
X
X
R
U
Fall and Spring
Migrant.
Yellow Warbler
Bayberry Thickets; Pond
Dendroica petechia
and Salt Marsh Fringes
X
C
C
C
Summer Resident; Fall
and Spring Migrant.
Table 3, cont.
Habitat Utilization
Seasonal Abundance
Family/Species
Habitat
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
in the Project Area
Parulidae Wood Warblers, cont.
Yellow-rumped Warbler
Barrier Beach;
Dendroica coronata
Bayberry Thickets
X
X
C
C
C
Winter Resident; Fall
and Spring Migrant.
Palm Warbler
Residential Areas;
Dendroica palmarum
Lawns; Gardens
X
R
C
U
Spring Migrant.
Common Yellowthroat
Geothlypis trichas
Interdune Thickets
PR X
R
C
C
C
Summer Resident; Fall
and Spring Migrant.
Ploceidae - Weaver Finches
House Sparrow
Passer domesticus
Residential Areas
PO
X
X
C
C
C
A
Resident.
Icteridae Blackbirds and Orioles
Eastern Meadowlark
Interdune Swales
Sturnella magna
and Grasslands
X
U
U
U
Winter Resident.
Red-winged Blackbird
Salt and Freshwater Marsh
33
Agelaius phoeniceus
Fringe; Shrubby Fields
CO
X
X
C
C
C
A
Resident.
Common Grackle
Quiscalus quiscula
Pine Groves; Salt Marsh
X
X
R
U
C
C
Resident.
Brown-headed Cowbird
Cosmopolitan;
Molothrus ater
Nest Parasite
X
X
C
C
C
C
Resident.
Fringillidae Finches
House Finch
Carpodacus mexicanus
Residential Areas
PR
X
C
C
C
C
Resident.
American Goldfinch
Thickets; Old Fields
Carduelis tristis
and Meadows
X
X
X
U
U
C
C
Resident.
Table 3, cont.
Habitat Utilization
Family/Species
Habitat
Seasonal Abundance
Breeding Migration Wintering Winter Spring Summer Fall
Principal Occurrence
In the Project Area
Fringillidae - Finches, cont.
Savannah Sparrow
Passerculus sandwichensis
Barrier Beach
X
X
R
R
Winter Resident;
Sharp-tailed Sparrow
Fall Migrant.
Ammospiza caudacuta
Salt Marsh
PO
X
X
U
c
U
Resident.
Seaside Sparrow
Ammospiza maritima
Salt Marsh
PO
X
U
U
Resident.
American Tree Sparrow
Spizella arborea
Residential Areas
X
C
Winter Resident.
White-throated Sparrow
Thickets;
Zonotrichia albicollis
Residential Areas
X
X
C
C
A
Winter Resident;
Fall and Spring
Fox Sparrow
Scrub-Shrub Fields
Migrant.
Passerella iliaca
and Meadows
X
U
Winter Resident
Song Sparrow
Scrub-Shrub Fields and
Melospiza melodia
Meadows; Pond Edges
PR
X
X
C
C
C
C
34
Resident.
Lapland Longspur
Barrier Beach; Old
Calcarius lapponicus
Fields and Meadows
X
R
Winter Resident.
Snow Bunting
Plectophenax nivalis
Barrier Beach
X
C
Winter Resident.
each inlet. Small fishes fed on by common terns and other such birds are
particularly abundant at inlets and their nearby mudflats. Outstanding areas
for feeding in the project area are the flats on the bay side of the inlet
near Ponquogue Bridge, where dabbling ducks feed on the stands of eelgrass and
beds of blue mussels; and the Warner Islands and adjacent sandbar area north
and northwest of the inlet (see Figure 1).
Relatively few species of birds nest in the project area. The most
significant nesting areas are three colonial waterbird colonies (Figure 4).
The "Shinnecock East" colony on the east side of the inlet contained 125 least
terns and two piping plovers during a 1984 survey. The "Warner Islands"
colony contained 450 common terns and 62 black skimmers in 1984, in addition
to nesting herring gulls, black-backed gulls, willets, and oystercatchers
(Buckley and Buckley, 1980; Buckley, pers. comm., 1984). Roseate terns have
also been known to nest at the Warner Islands colony in past years. The
"Ponquogue Beach East" site about three-fourths of a mile west of the inlet
contained 80 least terns and two piping plovers in 1984 (Buckley and Buckley,
1980; Peterson, pers. comm., 1984).
Common tern colonies on Long Island were apparently larger in the past
than in recent years. However, a 1984 Long Island tern survey reported a
colony of 450 common terns at the Warner Islands, although no common terns
were present at the Warner Islands in 1978 (Buckley and Buckley, 1980). This
is consistent with Buckley and Buckley's (1980) statement that the overall
number of occupied common tern colonies increased during the 1974-1978 period
of their study.
Least terns may never have been more abundant on Long Island than they are
at present, and populations appear to be holding their own despite intense
pressure from human activities (Buckley and Buckley, 1980).
Black skimmers, which nest at the Warner Islands and on Lane's Island west
of Ponquogue Bridge, apparently are also stable in population, with
populations on the south shore of Long Island almost always associated with
the major inlets and their common tern colonies. The still, shallow waters
black skimmers require for feeding apparently are scarce away from south shore
bays. Black skimmers often place their nests in patches of sand among the
tidal wrack; some individuals have even placed their nests on top of the wrack
(Buckley and Buckley, 1980).
The herring gull/black-backed gull breeding area at the Warner Islands is
one of 11 major breeding areas on Long Island. The black-backed gull colony
cluster, although much smaller than the colony at Gardiner's Island, is the
second largest on Long Island (Fire Island Inlet and Jamaica Bay were third
and fourth, respectively) (Buckley and Buckley, 1980).
Piping plovers appear historically never to have been common on Long
Island, but were more numerous than they are today. In 1939 there were an
estimated 500 pairs of piping plovers nesting on Long Island. By 1975 there
were an estimated 80-100 pairs. Ninety-nine nesting pairs were recorded in
1984, so it is possible their numbers are stabilizing, although at a level
much reduced from previous times.
35
Hempton Boys
High School
S 0 U
Springville
SHINNECOCK
BAY
Fonquogus
Ponquegue
Respecture
Werner
Islance
Warner Islands
US-COAS OCARD STA
Ponquages Pf
SOUTHAMPTON
Inleg
Shinnecock East
200
B
Boach
Ponquogue Bridge East
reason
+
"
as
Figure 4. Colonial waterbird colonies in the Shinnecock Inlet project area
(From D. Peterson, Seatuck Research Program Cornell University Laboratory of
Ornithology, letter dated 2 September 1984)
36
Least terns and piping plovers are species that appear to be restricted
exclusively to unvegetated sandy substrates, usually near inlets, for nesting
habitat, while common tern, roseate tern, and black skimmer require predator-
free islands for nesting. No roseate terns have been recorded this year in
the colonies within the project area. However, they have been known to nest
at the Warner Islands in the past (Erwin and Korschgen, 1979). The Lane's
Island tern colony just west of Ponquogue Bridge (Figure 4) contained 50
roseate terns, in addition to 1900 common terns and 5 black skimmers, in 1984,
so roseate terns probably feed within the project area. Roseate tern is
considered the most threatened colonial waterbird on Long Island (Buckley and
Buckley, 1980).
Twenty-two species of breeding birds were observed during field survey
visits to the east side of the Shinnecock Inlet project area by the U.S. Fish
and Wildlife Service for the Fire Island to Montauk study in 1982 (USDOI,
1983). The study found confirmed breeders associated with four principal
habitats: open sandy beach, backdune swales and thickets, salt marsh, and
residential areas. The open areas of unvegetated sandy beach supported the
previously mentioned "Shinnecock East" least tern/piping plover colony. Red-
winged blackbird (Agelaius phoeniceus) was the most abundant bird species in
the swales and thickets of the backdune area. Horned lark (Eremophila
alpestris) was also common in this habitat, and American robin (Turdus
migratorius) was present in small numbers. Song sparrow (Melospiza melodia),
common yellowthroat (Geothlypis trichas), ring-necked pheasant (Phasianus
colchicus) and northern mockingbird (Mimus polyglottos) nested in this habitat
as well. Sharp-tailed sparrow (Ammospiza caudacuta) and American
oystercatcher (Haematopus palliatus) were confirmed as breeding in the
bayshore beaches and adjacent salt marsh. Seaside sparrow (Ammospiza
maritima) was observed in this habitat as well, and was considered a possible
breeder. Willet (Catoptrophorus semipalmatus), marsh wren (Cistothorus
palastris), sharp-tailed sparrow, and seaside sparrow apparently depend
exclusively on bayshore salt marshes for nesting habitat.
The few residences in the project area provide nesting habitat for barn
swallow (Hirundo rustica), European starling (Sturnus vulgaris), house sparrow
(Passer domesticus) and house finch (Carpodacus mexicanus).
Mammals.
Nine mammalian species are known to occur in the project area on a regular
basis (Table 4). With the exception of the harbor seal (Phoca vitulina) all
are land mammals, and all of the land-based mammals except white-tailed deer
are small mammals. The great abundance of masked shrews, meadow voles and
white-footed mice provides an ample food base for the birds of prey that
migrate along the barrier islands or reside in the vicinity.
A number of other mammalian species may occur in the project area,
although signs of their habitation have not been observed. USDOI (1983)
listed 15 species of mammals that are known to inhabit the barrier island and
barrier beach ecosystems east of Moriches Inlet (Appendix A). At least some
of these species probably occur in the project area on a regular basis. Right
whale, finback whale, and humpback whale are not listed in Table 4, because
they would be found in the study area only as accidential strandings.
37
Table 4. Mammalian species known to occur regularly in the Shinnecock Inlet
study area.
Scientific Name
Common Name
Phoca vitulina
Harbor seal
Sorex cinereus
Masked shrew
Didelphis marsupialis
Opossum
Sylvilagus floridanus
Eastern cottontail
Microtus pennsylvanicus
Meadow vole
Peromyscus leucopus
White-footed mouse
Rattus norvegicus
Norway rat
Procyon lotor
Raccoon
Odocoileus virginianus
White-tailed deer
38
Shinnecock Inlet is one of the few areas on Long Island that show a
consistent (year-after-year) concentration of harbor seals. A population of
35-45 individuals can be found in the project area from approximately December
through April or May of each year, fishing off the rocks in the inlet and
"hauling out" on the sandbars north of the inlet at low tide. They are gone
from the area by mid-late May.
Connor (1971) states that the masked shrew (Sorex cinereus) is possibly the
most numerous mammal on Long Island. It has been found in almost every
habitat on Long Island with sufficient groundcover, regardless of whether the
area is wet or dry, or dominated by herbaceous or woody vegetation, and is
known to occur all along the outer barrier beaches of the south shore. The
masked shrew would be expected to occur in most of the project area, such as
the marshes, grassy areas and depressions among the dunes (Connor 1971).
Opossum (Didelphis marsupialis) is probably common in the project area.
Connor (1971) reported seeing opossums regularly in sandy and marsh-edge
habitats on the outer barrier beach between Moriches Inlet and Shinnecock
Inlet. U.S. Fish and Wildlife Service investigators (USDOI, 1983) routinely
observed tracks in the project area, particularly in interdune and backdune
areas and along the borders of the saltmarshes on the bay side of the barrier
island.
Eastern cottontail (Sylvilagus floridanus) is common along the full length
of the barrier island along Long Island's south shore, and is expected to be
common in the project area. The species uses a variety of maritime habitats,
including beachgrass and low shrubs among primary dunes, high and low thickets
and beachgrass areas of interdune zone, and high marsh and saltmarsh fringe
areas along the bay (Connor, 1971; USDOI, 1983).
Meadow vole (Microtus pennsylvanicus) is common in the project area (USDOI,
1983). It is expected to be particularly abundant in saltmarshes and marsh
fringe, and in the grassy-shrub areas of the outer dunes of the barrier beach.
White-footed mouse (Peromyscus leuopus) is probably the most generally
distributed mammal on Long Island (Connor, 1971), and is also common in the
area (USDOI, 1983). Connor (1971) commonly found this mammal in valleys and
depressions among the sand dunes and in grassy-shrubby areas that provided low
cover. Fewer were found in the beachgrass of the outer dunes. Salt marsh
appeared to be the least-preferred habitat (Connor, 1971; USDOI, 1983). USDOI
(1983) found this mammal in all vegetative communities within the study area.
Norway rats (Rattus norvegicus) are known to live year-round among the
rocks of the west jetty at the inlet, and probably occur throughout the
project area, including around structures found in the area. (Connor (1971)
noted that signs of rats are frequently found near inlets and ocean-front rock
jetties, and specifically discussed Shinnecock Inlet in this regard.
Signs of raccoon (Procyon lotor) presence have been observed in the project
area (USDOI, 1983) along the edge of the bayshore salt marshes. This mammal
is widespread on Long Island and probably can be encountered in most
39
parts of the project study area, since it has been observed along the outer
barrier beach from Moriches Inlet to Montauk Point and is known to frequent
the edges of protected salt water areas (Connor, 1971), such as those found
along the bay side of the barrier island.
USDOI (1983) observed sign of white-tailed deer (Odocoileus virginianus) in
the project area in shrubby saltmarsh fringe communities, in interdune mixed
herb-shrub communities and throughout the almost barren foredunes. At the
present time deer are numerous on the eastern half of Long Island; however,
their presence in the project area is probably restricted to the less
developed east side of the inlet.
Endangered and Threatened Species.
Nineteen New York State and/or Federal endangered or threatened species are
known to inhabit the Shinnecock Inlet project area or may occur in the area as
occasional transients or strandings (Table 5). These species include five
species of reptiles, nine species of birds, and five species of mammals.
The reptiles are all marine turtles that occur sporadically in the waters
of Long Island, particularly in the late summer and fall. They would be
expected to occur in the project area only as transients or strandings.
The piping plover (Charadrius melodus), common tern (Sterna hirundo), least
tern (Sterna albifrons) and roseate tern (Sterna dougallii) are confirmed as
nesting within the project area within recent years. The bald eagle
(Haliaeetus leucocephalus), northern harrier (Circus cyaneus), osprey (Pandion
haliaetus), peregrine falcon (Falco peregrinus) and loggerhead shrike (Lanius
ludovicianus) would occur only as regular migrants.
Sei whale (Balaenoptera borealis), humpback whale (Megaptera novaeanglinae)
and black right whale (Balaena glacialis) occur as migrants in the coastal
waters off the project area. Their presence within the study area would
probably be due to accidental stranding.
B. Aesthetic Attributes.
The Shinnecock Inlet project area is important to both recreational and
commercial fishing interests. People fish from boats, from the jetties, and
from the beach. The land portion of the project area is a diversified
landscape of barrier beach, dunes, and saltmarsh, partially county parkland
and partially Town of Southampton wetlands. Vistors to the area enjoy
sunbathing, swimming and surfing, as well as recreational walks and nature
study.
40
Table 5. State and Federally listed endangered and threatened species that
are either known to occur within the Shinnecock Inlet project area or may
occur in the area as occasional transients or strandings. E = endangered,
T = Threatened.
Federal
State
Status
Status
REPTILES:
Atlantic Green Sea Turtle
Chelonia mydas T
T
Atlantic Hawksbill Sea Turtle
Eretmochelys imbricata
E
E
Atlantic Loggerhead Sea Turtle
Caretta caretta T
T
Atlantic Ridley Sea Turtle
Lepidochelys kempii
E
E
Atlantic Leatherback Sea Turtle
Dermochelys coriacea
E
E
BIRDS:
Bald Eagle
Haliaeetus leucocephalus
E
E
Northern Harrier
Circus cyaneus
T
Osprey
Pandion haliaetus
T
Peregrine Falcon
Falco peregrinus
E
E
Piping Plover
Charadris melodus
Proposed T
T
Common Tern
Sterna hirundo
T
Roseate Tern
Sterna dougallii
E
Least Tern
Sterna albifrons
E
41
Table 5, cont.
Federal
State
Status
Status
BIRDS: cont.
Loggerhead Shrike
Lanius ludovicianus
E
MAMMALS:
Sperm Whale
Physeter catodon
E
E
Finback Whale
Balaenoptera physalus
E
E
Sei Whale
Balaenoptera borealis
E
E
Humpback Whale
Megaptera novaeanglinae
E
E
Right Whale
Balaena glacialis
E
E
42
IV. DISCUSSION AND CONCLUSIONS.
The Shinnecock Inlet project area contains a diversity of habitats: ocean,
bay (estuary), sand dune, barrier beach, salt marsh, etc. The area is rich in
marine resources and provides important habitat for many bird species,
including nesting habitat for the State-endangered roseate and least terns and
State-threatened common tern and piping plover. The area is relatively
unimportant in terms of mammalian, reptilian, or amphibian habitat, with the
exception of overwintering use of the area by harbor seals.
Five EQ (Environmental Quality) Resources have been identified in the
project area: Shinnecock Inlet, Shinnecock Bay, the nearshore portion of the
Atlantic Ocean, the barrier island, and the Warner Islands with adjacent
sandbar area. Tables 6 and 7 contain a preliminary analysis of these
resources and an evaluation framework for assessing project impacts upon EQ
Resources.
The magnitude and nature of project impacts upon area biological resources
cannot be fully assessed at this stage of project studies, since final plans
have not been determined. However, the following preliminary statements can
be made:
Benthic fauna.
Future with project. Benthic habitat will be disrupted by the work.
Juvenile organisms and individuals of relatively non-mobile species such as
polychaete worms will be destroyed. In the case of more mobile species such
as American lobster, various crabs, some mollusks and the like, many
individuals will be destroyed by the work; however, some will escape.
Following the work, most benthic habitat areas disturbed by construction
activities should be suitable for recolonization by species that are the same
or similar to those present prior to the work, provided the hydrology and
substrate of the dredged areas are not significantly changed by the work.
Some habitat areas will be converted to other habitat types by the project,
and therefore will develop a different community of species than was present
prior to the work These areas include areas converted from shallow water
habitat to intertidal habitat, or from intertidal habitat to habitat above
tidal influence by placement of the dredged material in the area of Tiana
Beach. Also included are the areas that would be covered or filled by
rehabilitation or extension of the jetties, such as areas that would be
covered by the placement of additional rocks or the small protected rocky
"cove" at the northern end of the east jetty, which would be filled. The
placement of additional rocks would improve habitat for American lobster, rock
crabs and other organisms attracted to rocky habitat, a type of habitat
uncommon the south shore of Long Island. The small cove would be converted to
unvegetated sand.
Dredging should not affect benthic resources through an increase in
salinity levels, since salinity levels in most of the bay are already near
ocean levels.
43
Table 6. Identification of EQ Resources in Shinnecock Inlet Project Area
EQ Attributes
Significance
Project Impacts
Institutional
Public
Technical
Resource
Ecological
Cultural
Aesthetic
Recognition
Recognition
Recognition
R1 Shinnecock
Tidal flushing
Navigational
Provides access
Inlets known
To be evaluated
Inlet
passsage for
to largest com-
to attract
commercial and
mercial landing
waterfowl.
Passage for
recreational
port in New York
Connect bay
aquatic organisms
vessels; rec-
State.
and ocean
traveling between
reational
habitats
bay and ocean.
fishing.
44
R₂ Shinnecock
Estuarine habitat
Long Island
Long Island
Acknowledged
Acknowledged
To be evaluated
Bay (within
(intertidal and
Intracoastal
Intracoastal
importance as
importance for
project area)
subtidal)
Waterway.
Waterway is a
as recreational
productive
Recreational
a Federally
shell- and fin-
shell- and fin-
and commercial
authorized
fishery
fishery, water-
fishing and
navigational
fowl habitat
boating.
channel
R₃ Nearshore
Shallow
Recreational
Popular fishing
To be evaluated
portion of
subtidal
shellfishing and
area
the Atlantic
habitat
finfishing
Ocean
R₄ Barrier
Component of
Diversified
Shinnecock Inlet
Estuarine marshes
Acknowledged
To be evaluated
Island to
coastal eco-
landscape
East and Shinne-
acknowledged as
component of
Low Low Water
system of south
(dunes, salt-
cock Inlet West
as important
littoral system,
(within pro-
shore of Long
marsh, beach,
county parks
components of
important in
ject area)
Island, with
etc.)
are on either
natural environ-
in protecting
dunes, beach,
side of inlet.
ment
mainland from
saltmarshes,
Saltmarsh
storm damage
etc.
areas are
Recreational
designated Town
area for
of Southhampton
swimming,
wetlands
Table 6. Identification EQ Resources in Shinnecock Inlet Project Area (continued)
EA Attributes
Significance
Project Impacts
Institutional
Public
Technical
Resource
Ecological
Cultural
Aesthetic
Recognition
Recognition
Recognition
R₄₀ cont.
sunbathing,
Study area east
nature study,
of the east
jetty is part
of a presently
designated
undeveloped
barrier island
unit (F12) in
the Coastal
Barrier Resources
System, under the
Coastal Barrier
Resources Act
of 1982 (CBRA).
Federal flood
insurance is
45
not available
in this area for
structures newly
built or sub-
stantally
improved on or
after Oct. 1,
1983. The remainder
of the study area is
part of a proposed
addition to the
system presently
under consideration
by the Department
of the Interior.
R5 Warner
Nesting and/or
Designated
Intermittent
To be evaluated
Islands and
resting area
Town of South-
nesting area
adjacent
for shorebirds,
ampton wetlands
for state-
sandbar
seabirds and
endangered and
harbor seals
and state-
threatened birds
Table 7. Evaluation Framework
Resource
Attributes
Indicators
Units
Guidelines
Techniques
R₁ Shinnecock
Ecological
Water quality
NYSDEC
Maintain existing
Water quality
Inlet
Water Quality
SA standard
monitoring
Classification
Minimum width
Feet
Maintain opening
Hydrographic
and depth
of sufficient size
surveys
to allow continued
passage of organisms
presently using inlet
46
Aesthetic
Minimum width
Feet
Increase safety
Hydrographic
and depth
and navigability of
surveys
inlet for vessels
R₂ Shinnecock
Ecological
Water quality
NYSDEC
Maintain existing SA
Water quality
Bay
Water Quality
standard
monitoring
Classification
Size of sub-
Acres
Minimize loss of
Hydrographic
tidal area
existing habitat
surveys
Substrate
Grain size
Limit dredging
Hydrographic
compositon
to amount needed
surveys
to accomplish
purposes of project
Aesthetic
Minimum channel
Feet
Maintain or achieve
Hydrographic
width and depth
authorized depth
surveys
in Long Island
and width in Long
Intracoastal
Island Intracoastal
Waterway
Waterway sections of
project area; avoid
disturbance of remain-
ing areas
Table 1, continued
Resource
Attributes
Indicators
Units
Guidelines
Techniques
R₃ Nearshore
Ecological
Water quality
NYSDEC
Maintain existing
portion of
Water quality
Water Quality
SA standard
the Atlantic
monitoring
Classification
Ocean
Size of subtidal
Acres
Minimize loss of
Surveys
shallow area
subtidal shallows
Substrate
Grain Size
Limit dredging
Hydrographic
composition
to amount necessary
surveys
for purposes of
project
Aesthetic
Water quality
NYSDEC
Maintain existing
Water quality
Water Quality
SA standard
monitoring
Classification
Water depth
Feet
Achieve project
Hydrographic
depth in constructed
surveys
channel; avoid dis-
turbance of remain-
ing areas.
47
subie ,, continued
Resource
Attributes
Indicators
Units
Guidelines
Techniques
R4 Ecological
Size and quality
Square feet,
Avoid disturbance to
Barrier
Survey
of undeveloped,
vegetation
these areas from
Island
vegetated areas
types
construction work
to Low Low
Water (within
project area)
Size and quality
Square feet
Increase size of
Survey
of undeveloped,
area adjacent to
unvegetated areas
west jetty
Width of barrier
feet
Increase width of
Survey
island
island adjacent to
west jetty
Substrate
Grain size
Utilize material with
Grain-size
Composition
grain size compatible
analysis
with existing beach
material
Water quality
NYSDEC
Maintain existing SA
Water quality
Water Quality
standard
monitoring
Classification
48
Aesthetic
Area of usable
Square feet
Increase area available
Survey
beach berm
for recreational use
Size of inter-
Square feet
Minimize loss of exist-
Survey
tidal zone
ing habitat in disposal
area; avoid disturbance
to existing marsh areas
Table 1, continued
Resource
Attributes
Indicators
Units
Guidelines
Techniques
R₅ Warner
Ecological
Size and type of
Square feet,
Avoid disturbance
Field
Island and
vegetated and
vegetation type
to existing habitat
investigation
adjacent
unvegetated areas
sandbar area
49
Future without project. Benthic habitat in the presently
dynamic/disturbed areas will continue to be disturbed by wave action. These
areas may also be periodically disturbed by Federal or non-Federal remedial
dredging actions in the project area. No significant change is anticipated in
areas that would be affected by work on the jetties, unless the east jetty
deteriorates to the point where the small cove is no longer protected from the
full tidal flush and is therefore destroyed.
Finfish.
Future with project. Adverse impacts of dredging should be minor, since
most fish would be able to avoid the area of impact during construction. Some
individuals, particularly juveniles, would be destroyed.
Extension of the jetties would create additional rocky habitat for finfish
use, at the expense of losing the existing dynamic sandy bottom. Since rocky
habitat is much scarcer than sandy bottom along the south shore of Long
Island, extending the jetties should have a positive effect upon finfish
resources.
Future without project. No significant change is anticipated, even if
periodic interim dreging should take place.
Amphibians, Reptiles.
Future with project. No significant change is anticipated.
Future without project. No significant change is anticipated.
Birds.
Future with project. Construction activity will temporarily disturb birds
in the vicinity of the project. If the work is performed outside of the
shorebird nesting season (approximately April 1 - June 30), no significant
adverse impacts from the work are expected. If the work is performed during
the shorebird nesting season, the resulting disturbance may force parental
birds to abandon nesting areas for the season. Likelihood of abandonment
would depend upon the magnitude of project disturbance, e.g. noise levels and
the proximity of construction equipment/activity to nesting areas. Birds that
abandon nesting sites in the project area might or might not subsequently be
able to nest súccessfully at some other location. If they are unable to nest
successfully, reproduction would be affected for the season.
If dredging occurs too close to the Warner Islands, some sloughing of the
banks could take place, with consequent loss of nesting habitat. The
potential for this will depend upon the channel alignment that is selected and
the amount and location of any dredging in the channel.
Future without project. No significant change in bird species is
anticipated over the short term. Least terns and piping plovers will
eventually cease nesting at the Ponquogue Bridge East and Shinnecock Inlet
East sites if these presently unvegetated areas become excessively
vegetated. Common terns, black skimmers and probably roseate terns should
continue to nest at the Warner Islands provided the islands remain free of
predators.
50
Mammals.
Future with project. Harbor seal is probably the only mammal species of
concern, since the Shinnecock Inlet study area is one of the few locations on
Long Island consistently used by overwintering harbor seals. Any dredging
operations conducted prior to December or after April would have limited or no
impact on the harbor seals. Operations conducted during the period of harbor
seal residence, however, could have a substantial impact. Some animals might
be accidentally killed. In addition, the general disturbance of construction
activities might cause the opoulation to desert the area for at least the
season and poossibly longer.
Future without project. No significant change is anticipated, provided
any interim dredging occurs outside the December-April period of harbor seal
residence.
Vegetation.
Future with project. The three species of rockweed now found in the small
cove area will be destroyed if the cove is filled as part of jetty
construction work. However, some rockweed plants will probably colonize the
jetties and revetment following completion of the work.
Future without project. No significant change is anticipated.
Rare and Endangered Species.
Future with Project. Piping plover, common tern, least tern and roseate
tern could be adversely affected if work is done during the shorebird nesting
season. The type of impact would be the same as that described for general
shorebirds nesting in the area, i.e. potential disturbance of nesting
activities, possible loss of reproduction for the season, and possible loss of
nesting habitat at the Warner Islands through sloughing.
Future without project. Endangered/threatened species would be expected
to continue to nest in the study area periodically, with numbers fluctuating
from year to year, provided the areas presently used for nesting remain free
from predators, human disturbance does not significantly increase, and least
tern/piping plover nesting areas remain unvegetated. It is unlikely that
structures will be built on or near the nesting areas in the future.
51
Water Quality.
Future with project. No significant longterm change is anticipated at
this time. Minor increases in turbidity will occur during the construction
period. Any increases in salinity should be negligible, since salinity levels
in most of the bay are presently near ocean levels.
Future without project. No significant change is anticipated.
SUMMARY.
The Shinnecock Inlet project area provides habitat for many aquatic and
terrestrial species. Nineteen New York State and/or Federally-endangered or
threatened species are known to inhabit the area or may occur as occasional
strandings or transients; piping plover, common tern, least tern and roseate
tern have nested within the study area in recent years. Harbor seals
consistently use the area for overwintering. The EQ Resources of the
Shinnecock Inlet project area are identified as Shinnecock Inlet, Shinnecock
Bay, the nearshore portion of the Atlantic Ocean, the barrier island, and the
Warner Islands and adjacent sandbar.
52
References
Briggs, P.T. 1965. The sport fishery in the surf on the south shore
of Long Island from Jones Inlet to Shinnecock Inlet. N.Y. Fish and Game
Journal 12: 31-47.
, 1968. The sport fisheries for scup in the inshore waters of eastern
Long Island. N.Y. Fish and Game Journal 15: 165-185.
Buckley, P.A. and F.G. Buckley. 1980. Population and colony-site trends of
Long Island waterbirds for five years in the mid 1970's. Transactions of
the Linnaean Society of New York. Vol. IX: 23-56.
Cerrato, R.M. 1983. Benthic borrow area investigations, south shore of
Long Island, New York. Marine Sciences Research Center, State University
of New York. Sponsored by the New York District, U.S. Army Corps of
Engineers. 654 PP.
Connor, P.F. 1971. The mammals of Long Island, New York. New York State
Museum & Science Service Bull. 416. 78 pp.
Erwin, R.M. and C.E. Korschgen. 1979. Coastal waterbird colonies: Maine to
Virginia, 1977. An atlas showing colony locations and species
composition. U.S. Fish and Wildlife Service Biological Services
Program. FWS/OBS-79/08. 647 PP. and appendices.
Franz, D.R. 1975. Distribution and abundance of inshore population of surf
clam, Spisula solidissima. In M. Grant Gross, ed. 1976. Middle Atlantic
Continental Shelf and the New York Bight. Proceedings of the Symposium,
American Museum of Natural History, New York City, 3,4, and 5 November
1975. American Society of Limnology and Oceanography, Inc. Special
Symposia Vol. 2: 404-413.
Glancy, J.B. 1956. Biological benefits of the Moriches and Shinnecock Inlets
with particular reference to pollution and the shell-fisheries. Report to
the District Engineer, U.S. Army Corps of Engineers, N.Y. District. 18
pp.
Gosner, K.L. 1971. Guide to identification of marine and esturine.
invertebrates, Cape Hatteras to the Bay of Fundy. New York: John Wiley &
Sons, Inc. 693 PP.
Grosslein, M.D. and T.R. Azorovitz. 1982. Fish distribution. MESA New York
Bight Atlas Monograph 15. Albany, N.Y.: New York Sea Grant Institute.
182 pp.
Hanlon, J.R. 1981. Fish sampling, Shinnecock Bay. U.S. Department of the
Interior, Fish and Wildlife Service. Unpublished data.
Long Island Regional Planning Board. 1978. A marine fisheries subplan for
Nassau and Suffolk counties. Prepared for the New York State Department
of State. 105 pp.
53
Marine Science Research Center. 1972. The marine wetlands of Nassau and
Suffolk counties, New York. Stony Brook, NY: State University of New
York at Stony Brook. 99 pp.
McHugh, J.L. and J.J.C. Ginter. 1978. Fisheries. MESA New York Bight Atlas
Monograph 16. Albany, NY: New York Sea Grant Institute. 129 pp.
Pagenkopf, J.R. and G.N. Bigham. 1977. Water quality evaluation, Moriches
Bay, Shinnecock Bay. Prepared by Tetra Tech, Inc., Smithtown, NY, for the
Nassau-Suffolk Regional Planning Board, Happauge, NY. 71 pp.
Pearce, J.B., D.J. Radosh, J.V. Caracciolo and F.W. Steimle, Jr. 1981.
Benthic fauna. MESA New York Bight Atlas Monograph 14.
Albany, N.Y.: New York Sea Grant Institute. 79 PP.
Pritchard, D.W. 1983. Final report, salinity measurements in Moriches Bay.
Prepared by Marine Sciences Research Center, State University of New York,
Stony Brook, N.Y. for the County of Suffolk Department of Health Services,
Riverhead, N.Y. 7 PP. and appendices.
Schaefer, R.L. 1967. Species composition, size and seasonal abundance of fish
in the surf waters of Long Island. New York Fish and Game Journal 14: 2-
46.
Suffolk County Department of Public Works, Long Island Regional Planning
Board, Southampton Fisheries Development Committee. 1982. Additional
information required by the United States Fish and Wildlife Service and
Corps of Engineers in accordance with the National Environmental Policy
Act for commercial fishery facility at Shinnecock Inlet. Capital Project
NO. 5349P. Phase II - preliminary design report. Prepared by Holzmacher,
McLendon and Murrell, P.C. 96 pp.
U.S. Army Engineer District, New York, Corps of Engineers. 1958. Moriches and
Shinnecock Inlets, Long Island, New York. Survey Report. 46 pp and
appendices.
U.S. Army Engineer District, New York, Corps of Engineers. 1974. Draft
environmental impact statement, Maintenance of Great South Bay Channel and
Patchogue River and Long Island Intracoastal Waterway, New York navigation
projects. 22 pp.
U.S. Army Engineer District, New York, Corps of Engineers. 1976. Draft
environmental impact statement for Fire Island Inlet to Montauk Point, New
York Beach Erosion Control and Hurricane Protection Project. Volume II:
Appendices. 309 PP.
United States Department of the Interior (USDOI), Fish and Wildlife Service.
1983. Fish and Wildlife resource studies for the Fire Island Inlet to
Montauk Point, New York Beach Erosion Control and Hurricane Protection
Project Reformulation Study: terrestrial resource component. 140 PP.
54
APPENDIX A
Checklist of mammals inhabiting the barrier island and barrier beach ecosystems of the Fire Inland Inlet to Montauk Point
Reformulation Study project area east of Moriches Inlet, Long Island, New York. Table values indicate the relative use by each
species of major geomorphological zones. A plus sign (+) denotes a high degree of utilization. An asterisk (*) indicates that the
information available was Insufficient to document the degree of utilization. A minus sign (-) denotes a low degree of
utilization. Data are after Connor (1971). (From USDOI, 1983).
Major Geomorphological Zone
Barrier Island
Barrier Beach
Primary Dune Intrerdune Bayshore
Primary Dune Interdune Upland Transition
Species
Zone
Zone
Zone
Zone
Zone
Zone
Opossum
Didelphis marsupialis
+
+
+
+
+
+
Masked shrew
Sorex cinereus
+
+
+
+
+
+
Short-tailed shrew
Blarina brevicauda
*
*
+
Eastern mole
Scalopus aquaticus
*
+
+
+
Little brown bat
Myotis lucifugus
#
*
*
A-1
*
Keen's myotis
Myotis keenli
*
*
Silver haired bat
Laisonycteris noctivagans
*
*
*
Major Geomorphological Zone
Barrier Island
Barrier Beach
Primary Dune Interdune Bayshore
Primary Dune Intrerdune Upland Transition
Species
Zone
Zone
Zone
Zone
Zone
Zone
Norway rat
Rattus norvegicus
+
+
+
+
+
+
Meadow jumping mouse
Zapus hudsonius
*
*
*
-
+
+
Red fox
Vulpes fulva
+
+
+
+
+
t
Raccoon
Procyon lotor
*
+
*
+
+
Longtail weasel
Mustela frenata
+
&
+
+
+
Mink
Mustela vison
*
+
*
+
+
Striped skunk
Mephitis mephitis
#
#
+
0
Harbor seal
A-2
Phoca vitulina
+
White-tailed deer
Odocoileus virginianus
+
+
+
+
+
+
Major Geomorphological Zone
Barrier Island
Barrier Beach
Primary Dune Interdune Bayshore Primary Dune Interdune Upland Transition
Zone
Zone
Zone
Zone
Zone
Zone
Species
Eastern Pipistrel
Pipistrellis subflavus
*
*
*
#
*
Big brown bat
Eptesicus fuscus
+
+
+
+
+
+
Red bat
Lasiurus borealis
+
+
+
+
+
+
Hoary bat
Lasiurus cinereus
*
Eastern Cottontail
Sylvilagus floridanus
+
+
+
+
+
+
White-footed mouse
Peromyscus leucopus
+
+
+
+
+
+
Meadow vole
Microtus pennsylvanicus
+
+
+
+
+
+
A-3
Muskrat
Ondatra zibethica
+
House mouse
Mus musculus
+
+
+
+
+