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Originally Processed With FOIA(s): FOIA Number: S S FOIA MARKER This is not a textual record. This is used as an administrative marker by the George Bush Presidential Library Staff. Record Group/Collection: George H.W. Bush Presidential Records Collection/Office of Origin: Speechwriting, White House Office of Series: Speech File Backup Files Subseries: Chron File, 1989-1993 OA/ID Number: 13779 Folder ID Number: 13779-010 Folder Title: The Hague 11/9/91 [OA 7564] [6] Stack: Row: Section: Shelf: Position: G 26 21 7 4 Ref. JX1705 United States Department of State A25 1988 WH Principal Officers of the Department of State and United States Chiefs of Mission 1778 - 1988 UNITED STATES CHIEFS OF MISSION 49 Finland (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Jack K. McFall D.C. C EE/MP 10 Sept. 1952 15 Nov. 1952 Recommissioned after confirmation 1 May 1953 Promoted to AE/P AE/P 15 Sept. 1954' 17 Sept. 19544 Recommissioned after confirmation 3 Dec. 1954 Left post, 19 Sept. 1955 John D. Hickerson Tex. C AE/P 4 Oct. 1955' 23 Nov. 1955 Recommissioned after confirmation 25 Jan. 1956 Left post, 3 Nov. 1959 Edson O. Sessions III. NC AE/P 20 Oct. 1959' 28 Nov. 1959 Recommissioned after confirmation 21 Jan. 1960 Left post, 20 Nov. 1960 Bernard Gufler Wash. C AE/P 24 Feb. 1961 14 Apr. 1961 Left post, 18 Apr: 1963 Carl T. Rowan Minn. NC AE/P 9 Mar. 1963 21 May 1963 Left post, 8 Feb. 1964 Tyler Thompson Me. C AE/P 31 July 1964 25 Aug. 1964 Left post, 14 June 1969 Val Peterson Nebr. NC AE/P 1 May 1969 14 July 1969 Left post, 23 Mar. 1973 V. John Krehbiel Cal. NC AE/P 27 Mar. 1973 1 June 1973 Left post, 24 Feb. 1975 Mark Evans Austad Utah NC AE/P 20 Feb. 1975 20 Mar. 1975 Left post, 14 Apr. 1977 Rozanne L. Ridgway D.C. C AE/P 26 May 1977 5 Aug. 1977 Left post, 20 Feb. 1980 James Eugene Goodby N.H. C AE/P 27 Feb. 1980 11 Apr. 1980 Left post, 18 Aug. 1981 Keith Foote Nyborg Id. NC AE/P 30 July 1981 18 Sept. 1981 Left post, 17 Feb. 1986 Rockwell Anthony Schnabel Cal. NC AE/P 17 Dec. 1985 28 Feb. 1986 4Legation Helsinki was raised to Embassy status on 10 Sept. 1954. France Name Res. Career Title Appointment Pres: of Cred. Term. of Mission Benjamin Franklin¹ Pa. MP 14 Sept. 1778 23 Mar. 1779 Superseded, 17 May 1785 Thomas Jefferson Va. MP 10 Mar. 1785 17 May 1785 Recommissioned 12 Oct. 1787 Left post, 26 Sept. 1789 William Short Va. CdA 20 Apr. 1790 14 June 1790 Presented recall, 15 May 1792 Gouverneur Morris N.Y. MP 12 Jan. 1792 3 June 1792 Recall requested by Govt. of France, 9 Apr. 17942 James Monroe Va. MP 28 May 1794 15 Aug. 1794 Presented recall, 9 Dec. 1796 Charles Cotesworth Pinckney³ S.C. MP 9 Sept. 1796' William Vans Murray4 MP James A. Bayard5 Del. MP 19 Feb. 1801 Robert R. Livingston N.Y. MP 2 Oct. 1801 6 Dec. 1801 Presented recall, 18 Nov. 1804 John Armstrong6 N.Y. MP 30 June 1804' 18 Nov. 1804 Left post, 14 Sept. 1810 Jonathan Russell R.I. CdA [5 Nov. 1810⁷] [⁸] Superseded, 17 Nov. 1811 Joel Barlow D.C. MP 27 Feb. 1811 17 Nov. 1811 Died at Zarnowiec, 26 Dec. 1812, en route to Paris from consultations with French officials in Russia William H. Crawford Ga. MP 9 Apr. 1813 Recommissioned after confirmation 28 May 1813 14 Dec. 1813 Reaccredited when France again became a kingdom. 16 Aug. 1814 Left post, 26-30 Apr. 1815 Albert Gallatin Pa. EE/MP 28 Feb. 1815 16 July 1816 Left post, 16 May 1823 James Brown La. EE/MP 9 Dec. 1823 13 Apr. 1824 Had farewell audience, 28 June 1829 William C. Rives Va. EE/MP 18 Apr. 1829 25 Oct. 1829 Recommissioned after confirmation 10 Feb. 1830 Reaccredited after change of government [14 Jan. 18319] Left post, 27 Sept. 1832 Levett Harris N.J. CdA 6 Mar. 1833 20 Apr. 1833 Superseded, 30 Sept. 1833 1Commissioned also to negotiate a treaty with Sweden. Nomination was confirmed by the Senate, but no record has been found 2Morris was still at his post when his successor presented credentials. of a new commission following confirmation. ³Proceeded to post, but was not received by the Directory; left post, 7Commission not of record, but enclosed with an instruction of this date. 5 Feb. 1797. Nomination was confirmed by the Senate, but no record has 8Received his commission about 13 Feb. 1811; was not issued a letter been found of a new commission following confirmation. of credence, but continued his official relations with the Govt. of France 4Not commissioned; nomination superseded by a nomination of Murray begun in Sept. 1810 as Chargé d'Affaires ad interim. and two others to serve on a joint commission. 9Formally received on this date. 5Did not serve under this appointment. 50 UNITED STATES CHIEFS OF MISSION France (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Edward Livingston EE/MP 29 May 1833' 30 Sept. 1833 Recommissioned after confirmation 5 Mar. 1834 Left post, 29 Apr. 1835¹⁰ Lewis Cass EE/MP 4 Oct. 1836 1 Dec. 1836 Left post, 12 Nov. 1842 Henry A. Wise¹¹ Va. EE/MP William R. King Ala. EE/MP 9 Apr. 1844 1 July 1844 Presented recall, 15 Sept. 1846 Charles J. Ingersoll12 Pa. EE/MP Richard Rush Pa. EE/MP 3 Mar. 1847 31 July 1847 Reaccredited when France again became a republic 26 Apr. 1848 Presented recall, 8 Oct. 1849 William C. Rives Va. EE/MP 20 July 1849 8 Nov. 1849 Recommissioned after confirmation 18 Mar. 1850 Reaccredited when France again became an empire 10 Jan. 1853 Presented recall, 12 May 1853 John Y. Mason Va. EE/MP 10 Oct. 1853 Recommissioned after confirmation 6 Dec. 1853 22 Jan. 1854 Died at post, 3 Oct. 1859 Charles J. Faulkner Va. EE/MP 16 Jan. 1860 4 Mar. 1860 Presented recall, 12 May 1861 William L. Dayton N.J. EE/MP 18 Mar. 1861 19 May 1861 Died at post, 1 Dec. 1864 John Bigelow N.Y. EE/MP 15 Mar. 1865' 23 Apr. 1865 Recommissioned after confirmation 22 Jan. 1866 Presented recall, 23 Dec. 1866 John A. Dix N.Y. EE/MP 24 Sept. 1866 23 Dec. 1866 Recommissioned after confirmation 2 Mar. 1867 Presented recall, 23 May 1869 Elihu B. Washburne III. EE/MP 17 Mar. 1869 23 Mar. 1869 Reaccredited when France again became a republic 8 May 1871 Presented recall, 5 Sept. 1877 Edward F. Noyes O. EE/MP 1 July 1877 5 Sept. 1877 Recommissioned after confirmation 30 Oct. 1877 Presented recall, 5 Aug. 1881 Levi P. Morton N.Y. EE/MP 21 Mar. 1881 5 Aug. 1881 Presented recall, 14 May 1885 Robert M. McLane Md. EE/MP 23 Mar. 1885 14 May 1885 Presented recall, 20 May 1889 Whitelaw Reid N.Y. EE/MP 23 Mar. 1889 21 May 1889 Left post, 25 Mar. 1892 T. Jefferson Coolidge Mass. EE/MP 12 May 1892 10 June 1892 Presented recall, 4 May 1893 James B. Eustis La. EE/MP 20 Mar. 1893¹³ AE/P 8 Apr. 1893 6 May 1893 Presented recall, 24 May 1897 Horace Porter N.Y. AE/P 19 Mar. 1897 26 May 1897 Presented recall, 2 May 1905 Robert S. McCormick III. AE/P 8 Mar. 1905 2 May 1905 Presented recall, 2 Mar. 1907 Henry White R.I. AE/P 19 Dec. 1906 23 Mar. 1907 Left France, 3 Nov. 1909 Robert Bacon N.Y. AE/P 21 Dec. 1909 31 Dec. 1909 Presented recall, 19 Apr. 1912 Myron T. Herrick O. AE/P 15 Feb. 1912 29 Apr. 1912 Left post, 28 Nov. 1914 William G. Sharp O. NC AE/P 19 June 1914 4 Dec. 1914 Presented recall, 14 Apr. 1919 Hugh Campbell Wallace Wash. NC AE/P 27 Feb. 1919 22 Apr. 1919 Presented recall, 5 July 1921 Myron T. Herrick O. NC AE/P 16 Apr. 1921 15 July 1921 Died at post, 31 Mar. 1929 Walter E. Edge N.J. NC AE/P 21 Nov. 1929 18 Dec. 1929 Presented recall, 13 Apr. 1933 Jesse Isidor Straus N.Y. NC AE/P 17 Mar. 1933 8 June 1933 Left France, 5 Aug. 1936 William Christian Bullitt Pa. NC AE/P 25 Aug. 1936 13 Oct. 1936 Recommissioned after confirmation 23 Jan. 1937 Left La Bourboule, 11 July 194014 William D. Leahy Ga. NC AE/P 29 Nov. 1940 8 Jan. 1941 Left Vichy, 1 May 1942¹⁵ Jefferson Caffery La. C AE/P 25 Nov. 1944 30 Dec. 1944¹⁶ Left post, 13 May 1949 David K. E. Bruce Va. NC AE/P 9 May 1949 17 May 1949 Left post, 10 Mar. 1952 James Clement Dunn N.Y. C AE/P 13 Mar. 1952 27 Mar. 1952 Left post, 2 Mar. 1953 C. Douglas Dillon N.J. NC AE/P 27 Feb. 1953 13 Mar. 1953 Left post, 28 Jan. 1957 Amory Houghton N.Y. NC AE/P 14 Mar. 1957 17 Apr. 1957 Left post, 19 Jan. 1961 James M. Gavin Mass. NC AE/P 22 Feb. 1961 21 Mar. 1961 Left post, 26 Sept. 1962 Charles E. Bohlen D.C., C AE/P 4 Sept. 1962 27 Oct. 1962 Left post, 9 Feb. 1968 Robert Sargent Shriver, Jr. III. NC AE/P 22 Apr. 1968 25 May 1968 Left post, 25 Mar. 1970 ¹⁰Thomas P. Barton served as Chargé Affaires ad interim until 8 Nov. 14Near the end of Bullitt's term of service, Anthony J. Drexel Biddle, Jr., 1835, when he closed Legation Paris, having been recalled. acted as Deputy Ambassador to France, 13-25 June 1940 "Not commissioned; nomination rejected by the Senate. 15S. Pinkney Tuck was serving as Chargé d'Affaires ad interim when 12Not commissioned; nomination rejected by the Senate. France severed diplomatic relations with the U.S., 8 Nov. 1942. ¹³Took oath of office, but did not proceed to post in this capacity. ¹⁶Embassy Paris was opened to the public 1 Dec. 1944 with Ambassador Caffery in charge pending presentation of his letter of credence. UNITED STATES CHIEFS OF MISSION 51 France (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Arthur K. Watson Conn. NC AE/P 8 Apr. 1970 6 May 1970 Left post, 30 Oct. 1972 John N. Irwin, II N.Y. NC AE/P 2 Feb. 1973 23 Mar. 1973 Left post, 20 Oct. 1974 Kenneth Rush N.Y. NC AE/P 19 Sept. 1974 21 Nov. 1974 Left post, 14 Mar. 1977 Arthur A. Hartman N.J. C AE/P 8 June 1977 7 July 1977 Left post, 14 Oct. 1981 Evan Griffith Galbraith Conn. NC AE/P 6 Nov. 1981 2 Dec. 1981 Left post, 15 July 1985 Joe M. Rodgers Tenn. NC AE/P 19 July 1985 20 Sept. 1985 Gabon1 Name Res. Career Title Appointment Pres. of Cred. Term. of Mission W. Wendell Blancké² Cal. C AE/P 12 Dec. 1960' 13 Jan. 1961 Recommissioned after confirmation 6 Feb. 1961 Superseded, 10 Oct. 1961 Charles F. Darlington N.Y. NC AE/P 20 Sept. 1961 18 Oct. 1961 Left post, 26 July 1964 David M. Bane Pa. C AE/P 22 July 1965 14 Aug. 1965 Left post, 29 June 1969 Richard Funkhouser N.J. C AE/P 13 June 1969 9 Aug. 1969 Left post, 2 Aug. 1970 John A. McKesson, III D.C. C AE/P 10 Dec. 1970 4 Feb. 1971 Left post, 1 June 1975 Andrew L. Steigman³ Md. C AE/P 10 June 1975 9 Aug. 1975 Left post, 21 Aug. 1977 Arthur T. Tienken Va. C AE/P 3 Feb. 1978 6 Mar. 1978 Left post, 19 July 1981 Francis Terry McNamara Vt. C AE/P 11 Dec. 1981 19 Jan. 1982 Left post, 3 Aug. 1984 Larry C. Williamson Cal. C AE/P 13 Aug. 1984 20 Nov. 1984 Left post, 21 Aug. 1987 Warren Clark, Jr. Conn. C AE/P 10 Aug. 1987 19 Sept. 1987 1Alan W. Lukens (resident at Brazzaville) presented credentials as Chargé ³Steigman and all subsequent Ambassadors were also accredited to the d'Affaires ad interim, 17 Aug. 1960. During Blancké's tenure as non-resident Democratic Republic of Sao Tomé and Principe and resident at Libreville. Ambassador, Embassy Libreville was established 20 Mar. 1961 with Walker A. Diamanti as Chargé d'Affaires ad interim. 2Accredited also to the Central African Republic, Chad, and Congo; resi- dent at Brazzaville. The Gambia¹ Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Mercer Cook2 III. NC AE/P 18 May 1965 9 Aug. 1965 Left Dakar, 1 July 1966 William R. Rivkin III. NC AE/P 13 Oct. 1966 16 Jan. 1967 Died at Dakar, 19 Mar. 1967 L. Dean Brown Md. C AE/P 18 Oct. 1967 18 Jan. 1968 Left Dakar, 15 Aug. 1970 G. Edward Clark D.C. C AE/P 12 Oct. 1970 24 Nov. 1970 Left Dakar, 16 Oct. 1973 O. Rudolph Aggrey D.C. C AE/P 23 Nov. 1973 17 Jan. 1974 Left Dakar, 10 July 1977 Herman J. Cohen N.Y. C AE/P 24 June 1977 29 Mar. 1978 Left Dakar, 21 July 1980 Larry Gordon Piper Tex. C AE/P 30 June 1980 21 Aug. 1980 Left post, 23 Aug. 1982³ Sharon Erdkamp Ahmad D.C. C AE/P 30 Sept. 19824 Robert Thomas Hennemeyer III. C AE/P 11 May 1984 20 June 1984 Left post, 27 June 1986 Herbert E. Horowitz Fla. C AE/P 12 Sept. 1986 24 Oct. 1986 ¹During Cook's tenure as non-resident Ambassador, Embassy Bathurst P. Wesley Kriebel, July-Nov. 1983; Alan Logan, Nov. 1983-Apr. 1984; and (now Banjul) was established 9 Sept. 1965 with John G. Gossett as Chargé Edward Brynn, May-June 1984. d'Affaires ad interim. 4Did not serve under this appointment. 2Ambassadors Cook through Cohen were also accredited to Senegal and resident at Dakar. 3Between Aug. 1982 and June 1984, the following officers served as Chargé Affaires ad interim: Owen W. Roberts, Aug. 1982-June 1983; German Democratic Republic1 Name Res. Career Title Appointment Pres. of Cred. Term. of Mission John Sherman Cooper Ky. NC AE/P 19 Sept. 1974 20 Dec. 1974 Left post, 28 Sept. 1976 David B. Bolen Colo. C AE/P 29 July 1977 22 Aug. 1977 Left post, 20 June 1980 1Embassy Berlin was established 9 Dec. 1974 with Brandon H. Grove, Jr., as Chargé d'Affaires ad interim. 90 UNITED STATES CHIEFS OF MISSION Peru (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission William D. Pawley Fla. NC AE/P 14 June 1945 20 July 1945 Left post, 27 Apr. 1946 Prentice Cooper Tenn. NC AE/P 2 May 1946 1 July 1946 Left post, 29 June 1948 Harold H. Tittmann, Jr. Mo. C AE/P 18 June 1948 27 Sept. 1948 Left post, 30 Mar. 1955 Ellis O. Briggs Me. C AE/P 24 Mar. 1955 27 Mar. 1955 Left post, 5 June 1956 Theodore C. Achilles D.C. C AE/P 29 May 1956 24 July 1956 Relinquished charge, 27 Jan. 1960 Selden Chapin D.C. C AE/P 18 Mar. 1960 7 May 1960 Left post, 7 Aug. 1960 James Loeb N.Y. NC AE/P 18 Apr. 1961 23 May 1961 Normal relations interrupted 18 July 1962; new Govt. of Peru still unrecognized by the U.S. when Loeb left post, 26 July 1962 J. Wesley Jones la. C AE/P 29 Nov. 1962 6 Feb. 1963 Recommissioned after confirmation 27 Feb. 1963 Left post, 2 June 1969 Taylor G. Belcher N.Y. C AE/P 19 Aug. 1969 29 Aug. 1969 Left post, Apr. 1974 Robert W. Dean III. C AE/P 14 Mar. 1974 2 May 1974 Left post, 17 June 1977 Harry W. Shlaudeman Cal. C AE/P 26 May 1977 28 June 1977 Left post, 20 Oct. 1980 Edwin Gharst Corr Okla. c AE/P 2 Oct. 1980 6 Nov. 1980 Left post, 11 Oct. 1981 Frank V. Ortiz, Jr. N.M. C AE/P 1 Oct. 1981 10 Nov. 1981 Left post, 27 Oct. 1983 David C. Jordan Va. NC AE/P 1 Mar. 1984 20 Mar. 1984 Left post, 17 July 1986 Alexander F. Watson Md. C AE/P 16 Oct. 1986 27 Nov. 1986 Philippines Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Paul V. McNutt Ind. NC AE/P 21 June 1946 4 July 1946 Left post, 22 Mar. 1947 Emmet O'Neal Ky. NC AE/P 10 June 1947 22 Sept. 1947 Left post, 28 Apr. 1948 Myron Melvin Cowen N.Y. NC AE/P 2 Mar. 1949 23 May 1949 Left post, 14 Nov. 1951 Raymond Ames Spruance Cal. NC AE/P 18 Jan. 1952 7 Feb. 1952 Left post, 1 Apr. 1955 Homer Ferguson Mich NC AE/P 22 Mar. 1955 12 Apr. 1955 Left post, 23 Mar. 1956 Albert F. Nufer N.Y. C AE/P 10 May 1956 20 July 1956 Died at post, 6 Nov. 1956 Charles E. Bohlen D.C. C AE/P 9 May 1957 4 June 1957 Left post, 15 Oct. 1959 John D. Hickerson Tex. c AE/P 13 Oct. 1959 13 Jan. 1960 Recommissioned after confirmation 21 Jan. 1960 Left post, 8 Dec. 1961 William E. Stevenson Colo. NC AE/P 15 Dec. 1961' Recommissioned after confirmation 30 Jan. 1962 5 Feb. 1962 Left post, 14 June 1964 William McCormick Blair, Jr. III. NC AE/P 8 June 1964 5 Aug. 1964 Left post, 21 Oct. 1967 G. Mennen Williams Mich. NC AE/P 15 May 1968 17 June 1968 Left post, 7 Apr. 1969 Henry A. Byroade Ind. C AE/P 22 July 1969 29 Aug. 1969 Left post, 25 May 1973 William H. Sullivan R.I. C AE/P 16 July 1973 6 Aug. 1973 Left post, 26 Apr. 1977 David D. Newsom Cal. C AE/P 21 Oct. 1977 11 Nov. 1977 Left post, 30 Mar. 1978 Richard W. Murphy Va. C AE/P 25 May 1978 8 June 1978 Left post, 10 Aug. 1981 Michael Hayden Armacost Md. NC AE/P 11 Feb. 1982 12 Mar. 1982 Left post, 18 Apr. 1984 Stephen Warren Bosworth Mich. C AE/P 12 Apr. 1984 4 May 1984 Left post, 2 Apr. 1987 Nicholas Platt D.C. C AE/P 10 Aug. 1987 27 Aug. 1987 Poland Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Hugh S. Gibson Cal. C EE/MP [16 Apr. 19191] 2 May 1919 Recommissioned after confirmation 26 June 1919 Presented recall, 3 May 1924 Alfred J. Pearson la. NC EE/MP 2 Apr. 1924 26 June 1924 Left post, 18 Aug. 1925 John B. Stetson, Jr. Pa. NC EE/MP 3 July 1925' 29 Aug. 1925 Recommissioned after confirmation 17 Dec. 1925 Left post, 29 Aug. 1929 Alexander P. Moore² Pa. NC AE/P 31 Jan. 1930 John N. Willys O. NC AE/P 8 Mar. 1930 24 May 1930 Left post, 30 May 1932 F. Lammot Belin Pa. C AE/P 2 Nov. 1932 13 Dec. 1932 Recess appointment expired, 4 Mar. 1933 1Commission (issued during a recess of the Senate) not of record; took oath of office on this date. 2Died in the U.S. before taking oath of office. UNITED STATES CHIEFS OF MISSION 91 Poland (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission James Michael Curley³ Mass. NC AE/P John Cudahy Wis. NC AE/P 13 June 1933 6 Sept. 1933 Left post, 23 Apr. 1937 Anthony J. Drexel Biddle, Jr.4 Pa. NC AE/P 4 May 1937 2 June 1937 Left London, 1 Dec. 1943⁵ Arthur Bliss Lane N.Y. C AE/P 21 Sept. 1944 4 Aug. 1945 Left post, 24 Feb. 1947 Stanton Griffis Conn. NC AE/P 15 May 1947 9 July 1947 Left post, 21 Apr. 1948 Waldemar J. Gallman N.Y. C AE/P 7 July 1948' 15 Oct. 1948 Recommissioned after confirmation 2 Mar. 1949 Left post, 8 July 1950 Joseph Flack Pa. C AE/P 20 Sept. 1950 30 Nov. 1950 Left Poland, 22 Apr. 1955 Joseph E. Jacobs S.C. C AE/P 1 Apr. 1955 23 May 1955 Left post, 23 July 1957 Jacob D. Beam N.J. C AE/P 26 June 1957 9 Aug. 1957 Left post, 30 Nov. 1961 John M. Cabot D.C. C AE/P 30 Jan. 1962 2 Mar. 1962 Left post, 24 Sept. 1965 John A. Gronouski Wis. NC AE/P 11 Sept. 1965 7 Dec. 1965 Left post, 26 May 1968 Walter J. Stoessel, Jr. Cal. C AE/P 24 July 1968 12 Sept. 1968 Left post, 5 Aug. 1972 Richard T. Davies Wyo. C AE/P 2 Dec. 1972 5 Jan. 1973 Recommissioned after confirmation 8 Feb. 1973 Left post, 5 Feb. 1978 William E. Schaufele, Jr. O. C AE/P 3 Feb. 1978 30 Mar. 1978 Left post, 11 Sept. 1980 Francis J. Meehan D.C. C AE/P 2 Oct. 1980 27 Oct. 1980 Left post, 11 Feb. 19836 John R. Davis, Jr.7 Cal. C AE/P 5 Feb. 1988 17 Mar. 1988 3Not commissioned; nomination withdrawn before the Senate acted 5Rudolf E. Schoenfeld was serving as Chargé 'Affaires ad interim when upon it. the mission of the Embassy near the Govt. of Poland established in England 4Biddle left Warsaw, 5 Sept. 1939, and followed the Govt. of Poland first was terminated, 5 July 1945. He closed the office at London on 31 July to France (Sept. 1939-June 1940) and later to England (where Biddle arrived 1945, on which date Embassy Warsaw was established with Ambassador 14 Mar. 1941). Rudolf E. Schoenfeld opened the Embassy near the Govt. Lane in charge pending presentation of his letter of credence. of Poland established in England, making his initial call as Chargé Affaires 6The following officers have since served as Chargé l'Affaires ad interim: ad interim on 21 Sept. 1940. Biddle was commissioned also to Belgium, Herbert E. Wilgis, Jr., Feb.-July 1983; and John R. Davis, Jr., Sept. Czechoslovakia, Greece, Luxembourg, the Netherlands, Norway, and 1983-Jan. 1987. Yugoslavia; resident at London during his service near those govts. 7Designated Chargé d'Affaires 9 Jan. 1987. Portugal Name Res. Career Title Appointment Pres. of Cred. Term. of Mission David Humphreys Conn. MR 21 Feb. 1791 13 May 1791 Presented recall, 25 July 1797 John Quincy Adams1 Mass. MP 30 May 1796 William Smith S.C. MP 10 July 1797 8 Sept. 1797 Presented recall, 9 Sept. 1801 Thomas Sumter, Jr.2 S.C. MP 7 Mar. 1809 7 June 1810 Presented recall, 24 July 1819 John Graham³ MP 6 Jan. 1819 24 July 1819 Left Rio de Janeiro, 13 June 1820 John James Appleton⁴ Mass. CdA Henry Dearborn, Sr. Mass. EE/MP 7 May 1822 [5] Had farewell audience, 30 June 1824 Thomas L. L. Brent Va. CdA 9 Mar. 1825 24 June 1825 Reaccredited after change of govt. 18 Jan. 1830 Left post on or soon after 28 Nov. 1834 Edward Kavanagh Me. CdA 3 Mar. 1835 25 July 1835 Relinquished charge, 19 Apr. 1841 Washington Barrow Miss. CdA 16 Aug. 1841 28 Dec. 1841 Presented recall, 20-24 Feb. 1844 Abraham Rencher NC CdA 22 Sept. 1843 Recommissioned after confirmation 11 Jan. 1844 20-24 Feb. 1844 Presented recall, 4 Nov. 1847 George W. Hopkins Va. CdA 3 Mar. 1847 4 Nov. 1847 Presented recall, 18 Oct. 1849 James Brown Clay Ky. CdA 1 Aug. 1849 18 Oct. 1849 Recommissioned after confirmation 18 Mar. 1850 Left post, 19 Aug. 1850 Charles B. Haddock N.H. CdA 10 Dec. 1850 17 June 1851 Presented recall, 16 June 1854 John L. O'Sullivan⁶ N.Y. CdA 16 Feb. 1854 16 June 1854 Promoted to MR MR 29 June 1854 19 Oct. 1854 Presented recall, 15 July 1858 1Did not serve under this appointment. ad interim from June 1820 until the Legation to Portugal at Rio de Janeiro 2Served at the court of Portugal in Brazil; resident at Rio de Janeiro. was closed in 1821 (his last dispatch dated 12 July 1821). 3Served at the court of Portugal in Brazil; resident at Rio de Janeiro. 5Arrived at Lisbon before 16 Aug. 1822; did not report date of presen- tation of credentials. 4Not commissioned; nomination to be Chargé d'Affaires at Rio de Janeiro ⁶Nominated 25 Feb. 1856 to be EE/MP; nomination withdrawn before rejected by the Senate. Appleton, however, served as Chargé d'Affaires the Senate acted upon it. 62 UNITED STATES CHIEFS OF MISSION Honduras (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Julius G. Lay D.C. C EE/MP 16 Dec. 1929 31 May 1930 Left post, 17 Mar. 1935 Leo J. Keena Mich. C EE/MP 22 Feb. 1935 19 July 1935 Left post, 1 May 1937 John D. Erwin Tenn. NC EE/MP 29 July 1937 8 Sept. 1937 Promoted to AE/P AE/P 27 Mar. 1943 27 Apr. 1943 Left post, 16 Apr. 1947 Paul C. Daniels N.Y. C AE/P 10 Apr. 1947 23 June 1947 Left post, 30 Oct. 1947 Herbert S. Bursley D.C. C AE/P 18 Dec. 1947 15 May 1948 Left post, 12 Dec. 1950 John D. Erwin Tenn. NC AE/P 1 Feb. 1951 14 Mar. 1951 Left Honduras, 28 Feb. 1954 Whiting Willauer Mass. NC AE/P 5 Feb. 1954 5 Mar. 1954 Left post, 24 Mar. 1958 Robert Newbegin N.H. C AE/P 26 Mar. 1958 21 Apr. 1958 Left post, 3 Aug. 1960 Charles R. Burrows O. C AE/P 27 Aug. 1960 3 Nov. 1960 Left post, 28 June 1965 Joseph J. Jova N.Y. C AE/P 7 June 1965 12 July 1965 Left post, 21 June 1969 Hewson A. Ryan Mass. C AE/P 9 Oct. 1969 5 Nov. 1969 Left post, 30 May 1973 Phillip V. Sanchez Cal. NC AE/P 24 May 1973 15 June 1973 Left post, 17 July 1976 Ralph E. Becker D.C. NC AE/P 13 Sept. 1976 27 Oct. 1976 Left post, 1 Aug. 1977 Mari-Luci Jarimillo N.M. NC AE/P 26 Sept. 1977 27 Oct. 1977 Left post, 19 Sept. 1980 Jack Robert Binns Ore. C AE/P 26 Sept. 1980 10 Oct. 1980 Left post, 31 Oct. 1981 Dimitri Negroponte N.Y. C AE/P 29 Oct. 1981 11 Nov. 1981 Left post, 30 May 1985 John Arthur Ferch O. C AE/P 18 July 1985 22 Aug. 1985 Left post, 9 July 1986 Everett Ellis Briggs N.H. C AE/P 16 Oct. 1986 4 Nov. 1986 Hungary¹ Name Res. Career Title Appointment Pres. of Cred. Term. of Mission U. Grant-Smith Pa. C CdA pro [²] 24 Jan. 1922 Left post, 28 Apr. 1922 tem Theodore Brentano III. NC EE/MP 10 Feb. 1922 16 May 1922 Presented recall, 6 May 1927 J. Butler Wright Wyo. C EE/MP 26 Feb. 1927 18 June 1927 Presented recall, 24 Oct. 1930 Nicholas Roosevelt N.Y. NC EE/MP 29 Sept. 1930' 12 Nov. 1930 Recommissioned after confirmation 16 Dec. 1930 Left post, 9 May 1933 John Flournoy Montgomery Cal. NC EE/MP 13 June 1933 1 Aug. 1933 Left post, 17 Mar. 1941 Herbert Claiborne Pell R.I. NC EE/MP 11 Feb. 1941 20 May 1941 Hungary severed diplomatic rela- tions with the U.S., 11 Dec. 1941³ H. F. Arthur Schoenfeld D.C. C EE/MP 15 Dec. 1945 26 Jan. 1946 Left post, 1 June 1947 Selden Chapin D.C. C EE/MP 10 Apr. 1947 9 July 1947 Declared persona non grata by Govt. of Hungary, 11 Feb. 19494 Nathaniel P. Davis N.J. C EE/MP 1 Sept. 1949 21 Oct. 1949 Left post, 18 May 1951 Christian M. Ravndal la. C EE/MP 3 Oct. 1951 11 Jan. 1952 Left post, 5 Aug. 1956 Edward T. Wailes5 D.C. C EE/MP 26 July 1956 Martin J. Hillenbrand III. C AE/P 13 Sept. 1967 30 Oct. 1967 Left post, 15 Feb. 1969 Alfred Puhan Va. C AE/P 1 May 1969 16 June 1969 Left post, 9 July 1973 Richard F. Pedersen Cal. NC AE/P 24 July 1973 10 Sept. 1973 Left post, 26 Mar. 1975 Eugene V. McAuliffe Mass. C AE/P 25 Mar. 1975 28 Apr. 1975 Left post, 15 Apr. 1976 Philip Mayer Kaiser N.Y. NC AE/P 7 July 1977 4 Aug. 1977 Left post, 9 Mar. 1980 Harry E. Bergold, Jr. Fla. C AE/P 3 Mar. 1980 31 Mar. 1980 Left post, 9 Nov. 1983 Nicolas M. Salgo Fla. NC AE/P 7 Oct. 1983 23 Nov. 1983 Left post, 1 Aug. 1986 Robie M.H. Palmer Vt. C AE/P 24 July 1986 8 Dec. 1986 1See under Austria for representatives to Austria-Hungary. 5Took oath of office and proceeded to post, but did not present creden- 2Not commissioned; letter of credence dated 27 Dec. 1921. Legation tials; left post, 27 Feb. 1957. During the period 1957-1967 each of the follow- Budapest was established 26 Dec. 1921, on which date Grant-Smith was ing officers served as Chargé d'Affaires ad interim for more than a year: granted provisional recognition as Chargé d'Affaires. Garret G. Ackerson, Jr., July 1957-Feb. 1961; Horace G. Torbert, Jr., Feb. 1961-Dec. 1962; Owen T. Jones, Dec. 1962-July 1964; Elim 3Hungary declared war on the U.S., 13 Dec. 1941. Pell left post, 16 Jan. O'Shaughnessy, Nov. 1964-Sept. 1966; Richard W. Tims, Sept. 1966-Oct. 1942. 1967. Tims was serving as Chargé d'Affaires ad interim when Legation 4Chapin left post, 17 Feb. 1949 Budapest was raised to Embassy status, 28 Nov. 1966. UNITED STATES CHIEFS OF MISSION 81 Nepal (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Chester Bowles Conn. NC AE/P 10 Oct. 1951 16 Feb. 1952 Left New Delhi, 23 Mar. 1953 George V. Allen N.C. C AE/P 11 Mar. 1953 5 July 1953 Left New Delhi, 30 Nov. 1954 John Sherman Cooper Ky. NC AE/P 4 Feb. 1955 3 June 1955 Left New Delhi, 23 Apr. 1956 Ellsworth Bunker Vt. NC AE/P 28 Nov. 1956' Recommissioned after confirmation 25 Jan. 1957 8 Mar. 1957 Superseded, 25 Nov. 1959 Henry E. Stebbins Mass. C AE/P 9 Sept. 1959 25 Nov. 1959 Left post, 10 June 1966 Carol C. Laise D.C. C AE/P 19 Sept. 1966 5 Dec. 1966 Left post, 5 June 1973 William I. Cargo Fla. C AE/P 16 July 1973 28 Sept. 1973 Left post, 3 Apr. 1976 Marquita M. Maytag Cal. NC AE/P 3 Mar. 1976 18 May 1976 Left post, 22 Apr. 1977 L. Douglas Heck Ore. C AE/P 26 May 1977 29 July 1977 Left post, 19 May 1980 Philip R. Trimble N.Y. NC AE/P 23 May 1980 10 July 1980 Left post, 21 Feb. 1981 Carleton S. Coon, Jr. N.H. C AE/P 11 June 1981 3 July 1981 Left post, 3 Aug. 1984 Leon Jerome Weil N.Y. NC AE/P 13 Aug. 1984 21 Sept. 1984 Left post, 11 Nov. 1987 Milton Frank Cal. NC AE/P 28 Mar. 1988 22 Apr. 1988 Netherlands Name Res. Career Title Appointment Pres. of Cred. Term. of Mission John Adams1 Mass. MP 1 Jan. 1781 Apr. 17822] Transmitted recall by note from London, 30 Mar. 1788³ William Livingston4 N.J. MP John Rutledge5 S.C. MP William Short Va. MR 16 Jan. 1792 18 June 1792 Left post, 19 Dec. 1792 John Quincy Adams⁶ Mass. MR 30 May 1794 6 Nov. 1794 Presented recall, 20 June 1797 William Vans Murray⁷ Md. MR 2 Mar. 1797 20 June 1797 Presented recall, 2 Sept. 1801 William Eustis Mass. EE/MP 19 Dec. 1814 [20 July 1815⁸] Had farewell audience, 5 May 1818 Alexander H. Everett Mass. CdA 27 June 1818 Recommissioned after confirmation 30 Nov. 1818 4 Jan. 1819 Had farewell audience, 7 Apr. 1824 Christopher Hughes9 Md. CdA 9 Mar. 1825 10 July 1826 Superseded, 28 Jan. 1830 William Pitt Preble Me. EE/MP 1 June 1829 28 Jan. 1830 Recommissioned after confirmation 10 Feb. 1830 Left post on or shortly before 2 May 1831 Auguste Davezac La. CdA 15 Oct. 1831' 30 Dec. 1831 Recommissioned after confirmation 3 Jan. 1832 Superseded, 13 July 1839 Harmanus Bleecker N.Y. CdA 15 May 1839 13 July 1839 Recommissioned after confirmation [19 Mar. 1840¹⁰] Superseded, 22 Aug. 1842 Christopher Hughes Md. CdA 12 May 1842 22 Aug 1842 Presented recall, 28 June 1845 Auguste Davezac La. CdA 19 Apr. 1845' 28 June 1845 Recommissioned after confirmation 3 Feb. 1846 Superseded, 16 Sept. 1850 George Folsom N.Y. CdA 4 May 1850¹¹ 16 Sept. 1850 Presented recall, 11 Oct. 1853 August Belmont¹² N.Y. CdA 24 May 1853' 11 Oct. 1853 Recommissioned after confirmation 8 Feb. 1854 Promoted to MR MR 29 June 1854 26 Sept. 1854 Presented recall, 22 Sept. 1857 Henry C. Murphy N.Y. MR 1 June 1857' 24 Sept. 1857 Recommissioned after confirmation 14 Jan. 1858 Presented recall, 8 June 1861 James S. Pike Me. MR 28 Mar. 1861 8 June 1861 Left post on or soon after 29 May 1866 Daniel E. Sickles¹³ N.Y. MR 11 May 1866 John A. Dix14 N.Y. MR 27 July 1866 Albert Rhodes CdA [15] 19 Oct. 1866 Superseded, 1 Dec. 1866 1Commissioned also to Great Britain (see under United Kingdom); resi- 7Commissioned to the Batavian Republic. dent at London after 1785. Adams also received a second set of instruc- 8Formally received on this date. tions dated 16 Aug. 1781. 9Nominated 11 Dec. 1828 to be EE/MP; nomination tabled by the Senate. 2Formally recognized on this date. 10Commission not of record, but enclosed with an instruction of this date. 3Adams, before leaving The Hague at the end of his longest period of residence there, presented Charles W. F. Dumas as Chargé Affaires ad "The record copy is so dated, but the date is probably erroneous, as interim on 15 Oct. 1782. Dumas, although holding no commission from the Senate confirmed Folsom's nomination on 14 May 1850. the United States, continued to act in this capacity, except during Adams' 12Nominated 25 Feb. 1856 to be EE/MP; nomination withdrawn before later visits to the Netherlands, until 1790. the Senate acted upon it. 4Elected 23 June 1785 to be MP to the United Netherlands; declined 13Declined appointment. appointment. 14Declined appointment. Elected 5 July 1785 to be MP to the United Netherlands; declined 15Not commissioned; letter of credence dated 29 Sept. 1866. appointment. 6Continued to serve, without reaccreditation, after the proclamation of the Batavian Republic. 82 UNITED STATES CHIEFS OF MISSION Netherlands (Continued) Name Res. Career Title Appointment Pres. of Cred. Term. of Mission Hugh Ewing Kans. MR 24 Sept. 1866' 1 Dec. 1866 Recommissioned after confirmation 2 Mar. 1867 Left post on or soon after 31 Oct. 1870 Joseph P. Root¹⁶ Kans. MR Charles T. Gorham Mich. MR 12 July 1870 15 Dec. 1870 Presented recall, 9 July 1875 Francis B. Stockbridge¹⁷ Mich. MR 12 July 1875' James Birney Mich. MR 10 Jan. 1876 29 Mar. 1876 Left post on or soon after 20 Apr. 1882 William L. Dayton N.J. MR 26 Apr. 1882 26 Sept. 1882 Presented recall, 8 June 1885 Isaac Bell, Jr. R.I. MR 2 Apr. 1885 8 June 1885 Presented recall, 29 Apr. 1888 Robert B. Roosevelt N.Y. MR 16 May 1888 10 Aug. 1888 Promoted to EE/MP EE/MP 10 Aug. 1888 26 Sept. 1888 Presented recall, 17 May 1889 Samuel R. Thayer Minn. EE/MP 19 Mar. 1889 24 May 1889 Presented recall, 7 Aug. 1893 William E. Quinby Mich. EE/MP 24 May 1893 11 Aug. 1893 Recommissioned after confirmation 25 Aug. 1893 Presented recall, 26 July 1897 Stanford Newel1⁸ Minn. EE/MP 11 May 1897 19 Aug. 1897 Recommissioned to a combination of countries 5 June 1903 Recommissioned after confirmation 16 Nov. 1903 Presented recall, 30 June 1905 David J. Hill19 N.Y. EE/MP 15 Mar. 1905 15 July 1905 Presented recall, 1 June 1908 Arthur M. Beaupré III. EE/MP 2 Apr. 1908 15 June 1908 Transmitted recall by note, 25 Sept. 1911 Lloyd Bryce N.Y. EE/MP 12 Aug. 1911 16 Nov. 1911 Presented recall, 10 Sept. 1913 Henry van Dyke N.J. NC EE/MP 27 June 1913 15 Oct. 1913 Presented recall, 11 Jan. 1917 John W. Garrett Md. C EE/MP 23 Aug. 1917 11 Oct. 1917 Left post, 18 June 1919 William Phillips Mass. C EE/MP 3 Mar. 1920 23 Apr. 1920 Left post, 11 Apr. 1922 Richard M. Tobin Cal. NC EE/MP 27 Feb. 19232⁰ 5 Mar. 1923 1 May 1923 Recommissioned after confirmation 12 Dec. 1923 Left post, 29 Aug. 1929 Gerrit John Diekema Mich. NC EE/MP 11 Sept. 1929 20 Nov. 1929 Died at post, 20 Dec. 1930 Laurits S. Swenson Minn. NC EE/MP 28 Feb. 1931 29 Apr. 1931 Left post, 5 Mar. 1934 Grenville T. Emmet²¹ N.Y. NC EE/MP 27 Dec. 1933 15 Jan. 1934 21 Mar. 1934 Left post, 21 Aug. 1937 George A. Gordon N.Y. C EE/MP 30 July 1937 10 Sept. 1937 Govt. left the Netherlands, 13 May 1940, in anticipation of German occupation.22 Anthony J. Drexel Biddle, Jr.23 Pa. NC EE/MP 11 Feb. 1941 27 Mar. 1941 Promoted to AE/P AE/P 12 May 1942 [8 May 194224] Left London, 1 Dec. 1943 Stanley K. Hornbeck²⁵ Colo. NC AE/P 21 Sept. 1944 8 Dec. 1944 Left post, 7 Mar. 1947 Herman B. Baruch N.Y. NC AE/P 13 Mar. 1947 12 Apr. 1947 Left post, 26 Aug. 1949 Selden Chapin D.C. C AE/P 7 Oct. 1949 27 Oct. 1949 Left post, 30 Oct. 1953 H. Freeman Matthews D.C. c AE/P 1 Oct. 1953 25 Nov. 1953 Recommissioned after confirmation 26 Jan. 1954 Left post, 11 June 1957 Philip Young N.Y. NC AE/P 28 Mar. 1957 27 June 1957 Left post, 20 Dec. 1960 John S. Rice Pa. NC AE/P 29 Mar. 1961 6 May 1961 Left the Netherlands, 27 May 1964 William R. Tyler D.C. C AE/P. 6 May 1965 23 June 1965 Left post, 20 June 1969 J. William Middendorf II Conn. NC AE/P 13 June 1969 9 July 1969 Left post, 10 June 1973 Kingdon Gould, Jr. Md. NC AE/P 28 Sept. 1973 18 Oct. 1973 Left post, 30 Sept. 1976 Robert J. McCloskey Pa. C AE/P 3 Sept. 1976 22 Oct. 1976 Left post, 10 Mar. 1978 Geri M. Joseph Minn. NC AE/P 18 July 1978 6 Sept. 1978 Left post, 17 June 1981 William Jennings Dyess Ala. C AE/P 30 July 1981 2 Sept. 1982 Left post, 19 July 1983 L. Paul Bremer III Conn. C AE/P 6 July 1983 31 Aug. 1983 Left post, 25 Aug. 1986 John Shad D.C. NC AE/P 15 June 1987 24 June 1987 16Not commissioned; nomination withdrawn before the Senate acted Netherlands established in England, making his initial call as Chargé upon it. l'Affaires ad interim on 15 Aug. 1940. 17Took oath of office, but did not proceed to post. 23Served near the Govt. of the Netherlands established in England; com- ¹⁸Newel's second and third commissions were to the Netherlands and missioned also to Belgium, Czechoslovakia, Greece, Luxembourg, Norway, Luxembourg; resident at The Hague. Poland, and Yugoslavia; resident at London. 19Representatives from Hill through Phillips were also accredited to 24Formally received, and the Legation raised to Embassy status, on this Luxembourg and resident at The Hague. date. 20Commissioned to the Netherlands and Luxembourg; did not serve 25Served near the Govt. of the Netherlands established in England; resi- under this appointment. His later commissions were to the Netherlands only. dent first at London; transferred the Embassy to The Hague, 17 Aug. 1945. 21Did not serve under this appointment. The office of the Embassy in London was closed, 19 Sept. 1945. 22Gordon closed the Legation, 15 July 1940, and left post, 16 July 1940. Rudolf E. Schoenfeld established the Legation near the Govt. of the Dams in The vulnerability of the Netherlands The Delta Project Over half of the Netherlands lies below sea level. Just how The outcome of this determination was the Delta Project. the Delta vulnerable the country is to flooding was demonstrated on the The Project's principal goal was to improve the safety of the night of 1 February 1953. The combination of a spring tide southwest Netherlands by considerably shortening and re- and a persistent, violent northwesterly storm recreated on a inforcing the coastline. It was decided that dams should be particularly large scale an event which happened many constructed across inlets and estuaries, considerably reducing 1 times over the centuries. Waves destroyed the dykes and the the possibility of the sea surging into the land once more. sea rushed into the polders. The results were catastrophic: Freshwater lakes would form behind them. Roads along the 1,835 people drowned and many thousands of cows, horses, dams would improve access to the islands of Zeeland and pigs and chickens were killed. The floods destroyed 47,000 South Holland. Dams could not be constructed across the New homes, as well as schools, churches and other buildings. Appro- Waterway or the Western Scheldt, as these important shipping ximately 500 kilometres of dykes were completely or partially routes to the seaports of Rotterdam and Antwerp had to be destroyed and 200,000 hectares of land was flooded. The har- kept open. The safety of these areas was to be guaranteed by dest hit areas were the province of Zeeland, the southern part substantially reinforcing the dykes. of South Holland and the western part of North Brabant. The Delta Project is one of the largest hydraulic engineering The bewilderment and shock felt by people in the rest of the projects that has ever been carried out anywhere in the world. Netherlands when they learnt of the extent of the flooding New hydraulic engineering techniques were gradually develop- soon gave way to determination, and great efforts were made ed for the construction of the eleven dams and barriers of to reseal the breached dykes. The last breach, near Ouwerkerk various sizes which were built over a period of thirty years. on Schouwen-Duiveland, was resealed at the beginning of November 1953. Rarely have the people of the Netherlands In the early 1970s the realization grew that it was important tc been so united as when they decided that such a catastrophe preserve as much of the natural environment as possible, and should never happen again. this point of view has left its mark on the Delta Project. As a result the original plans were changed: not all of the inlets, 3 distributaries and estuaries between the Western Scheldt and the New Waterway have been transformed into freshwater lakes as was initially intended; there are now very distinct water systems, each with its own characteristic function. 5 You can now drive along the roads constructed on top of the dams and visit all the major Delta works and water systems in a single day. It does not matter where your journey begins or which direction you take. There is no systematic route one could follow to visit the dams and barriers in the same 6 sequence in which the project was carried out. Yet the Delta Project was carried out in anything but a random order. Work began on the relatively simpler parts, so that the experience gained could be used during the construction of larger, more 2 difficult dams across inlets and estuaries with strong tidal cur- rents. That was how the Delta works progressed: new hydrau- lic engineering techniques were first applied on a small scale and then used in the larger projects. The last dam in the Delta Project was completed in the spring of 1987 and lies at the junction of the provinces of Zeeland, North Brabant and South Holland. Its completion marked the end of thirty years' construction work on a chain of dams and other hydraulic engineering works to protect the southwest Netherlands from flooding. The Hollandse IJssel The Veerse Meer The Grevelingenmeer Engineers from the Public Works Department first turned After the storm surge barrier in the Hollandse Ussel was The construction of the Grevelingen dam (completed in their attention to the Hollandse IJssel, a river with an open completed, a start was made on the first major dams in the 1965) entailed a more extensive use of the seabed protec- passage to the sea via the Nieuwe Maas. A storm surge bar- turbulent tidal inlets. In line with the principle of working tion techniques that had been tested in the Zandkreek and rier was built at Krimpen to protect one of the lowest lying from small to large, the first project was the Three Islands the Veerse Gat. The six-kilometre dam between Schouwen- and most densely populated areas of the Netherlands. Project, which entailed the construction of dams in the Duiveland and Goeree-Overflakkee crosses the channels on Under normal conditions, the gates of the barrier, which Zandkreek between North and South Beveland and in the either side of the Oude Tong sandbar. The section on the was completed in 1958, are raised 12 metres above the Veerse Gat between North Beveland and Walcheren. During sandbar itself was built by pumping sand onto it. The sou- waterlevel, so that there is no obstruction to shipping. If the the construction of the Zandkreek dam asphalt was used for thern channel was dammed using the same type of small tide rises to a dangerously high level, the gates can be lowe- the first time to cover the sill which would support the cais- caissons that had been used in the Zandkreek dam, but a red to dam the river. A lock allows ships to travel up or sons, huge concrete structures which can be positioned new technique was developed for the larger channel to the downstream when the barrier is closed. quickly to dam the tidal inlet. The Zandkreek dam was com- north: a cableway was spanned across the channel and cable pleted in 1960. cars tipped stone into the water. The seven caissons used a year later to dam the Veerse Gat A substantial part of the dam built across the Brouwersha- were even larger. Sluices in the caissons allowed the tide to vense Gat, which forms the western boundary of the Greve- ebb and flow without obstruction. This prevented the cur- lingenmeer, was also constructed on sandbars using the rent from becoming too strong while the mouth of the pumping method. The northern channel was dammed with channel was gradually being dammed. When all seven were sluice caissons. These remained open until the dam in the in position the steel sluice gates were closed simultaneously southern channel, which was constructed using a cableway, and the caissons filled with sand. A substantial part of the had risen well above the water level. Then the sluice gates dam had already been built on a sandbar in the Veerse Gat were closed and the dam across the two tidal channels was by pumping sand onto it. The Veerse Meer, the lake formed completed using sand. after the dam was completed, is partly brackish due to dilu- tion by rainwater. Land that has been reclaimed is now used The Brouwers dam was completed in 1971, and the area for farming or recreational purposes and a few sandbars behind it is now a lake, the Grevelingenmeer. The loss of the have been left entirely to nature. tide and the gradual reduction in the salt content of the water led to the death of many plants and animals. Within a few years, though, nature adapted to the new conditions. After a sluice had been constructed in the Brouwers dam to allow water to flow between the Grevelingenmeer and the North Sea, the lake developed into a very valuable area for nature conservation, the fishing industry and recreational purposes. A sluice has also been constructed in the Grevelin- gen Dam and the Grevelingenmeer can be 'flushed' with water from the North Sea to keep the salt and oxygen con- tent high. The Haringvliet The Eastern Scheldt The Storm Surge Barrier The Volkerak dam separates the Hollandsch Diep and the While the Haringvliet dam and the Brouwers dam were nea- A compromise was reached in 1976: a storm surge barrier, Haringvliet from the southern part of the Delta and pre- ring completion, preparations had already begun for the which would stay open under normal conditions but which vents fresh water from the Rhine and the Maas flowing construction of the dam across the mouth of the Eastern could be closed at very high tides. The construction of the southward. The Volkerak dam, completed in 1965, comprises Scheldt, the last, largest and also most complex part of the storm surge barrier meant a break with the policy that the the Hellegatsplein, a dam extending to Goeree-Overflakkee Delta Project. Three islands were constructed: Roggenplaat, Public Works Department and the hydraulic engineering and a second dam with a large lock complex extending in Neeltje Jans and Noordland. A pumped sand dam was built contractors in the Netherlands had pursued in working from the direction of North Brabant. A road bridge has been built between the latter two. In the remaining channels the first small to large and from relatively simple to complex. The from the Hellegatsplein to the Hoekse Waard. The dam to steel towers were built for the cableway, as it was planned storm surge barrier needed expertise that had yet to be Goeree-Overflakkee was built with pumped sand. Twelve to dam the Eastern Scheldt using this well-tried method. developed and experience that had yet to be gained. Exten- sluice caissons were needed to dam the southeastern chan- Its completion date was set for 1978. sive research was carried out to determine the feasibility of nel. building the storm surge barrier, taking full account of the At the end of the 1960s however protests were voiced interests of the environment, flood protection, and the The Haringvliet dam on the western side of the Haringvliet about the project. Scientists became aware of the special fishing and shipping industries. has two purposes. It must not only protect the waters significance of the flora and fauna in and around the The actual construction of the storm surge barrier also had inland from high tides, but must also discharge excess water Eastern Scheldt. The sandbars and mud flats exposed at low to be thoroughly studied. The solution was a barrier consis- from the Rhine and the Maas. The construction of the tide are important feeding grounds for birds, and the ting of pre-fabricated concrete and steel components that 4.5 kilometre Haringvliet dam therefore began with the estuary is a nursery for fish from the North Sea. Fishermen were assembled in the three channels at the mouth of the building of a large sluice complex. The 17 sluices can and action groups made sure that the scientific findings Eastern Scheldt. 65 colossal concrete piers from the barrier's discharge an enormous volume of water. Closing or opening were heard by the government and parliament. A heated backbone. A stone sill and a concrete sill beam were placed the sluices determines how much water has to be dischar- debate flared up. Opponents of the dam believed that the between each of the piers, and the openings could be closed ged by the alternative route via the New Waterway. By safety of the region could be guaranteed by raising the with steel gates. Concrete box girders were placed on top of channelling as much water as possible through the New height of the dykes along the Eastern Scheldt. The inlet the piers to form a road deck. Waterway to the North Sea, saltwater is prevented from would then remain open and saline. The equally vigorous penetrating deep inland and making the groundwater supporters of the solid dam, for example agricultural and The seabed also needed special consideration. A new techni- saline. The sluice complex in the Haringvliet dam is called water boards, appealed to the emotions of the Zeelanders, que was required to prevent the strong current in the the 'tap of the Netherlands' because of its vital significance asking whether the consequences of the flood disaster of mouth of the river from washing away the sand on which to the country's water management. The channel on the 1953, had already been forgotten. the piers were to stand. The solution was to place the piers southern side of the discharge sluices was dammed with on mattresses filled with graded layers of sand and gravel sand, and that on the northern side using the cableway which would allow water to flow through but trap the sand. method. The dam was completed in 1971. There is now no tide in the Haringvliet and it consist entirely of freshwater. The Zoommeer The Monument The construction of the storm surge barrier also required The storm surge barrier has narrowed the mouth of the The place where the Philips dam joins up with the Grevelin- the development of special equipment. The 'Mytilus' made Eastern Scheldt, and less water now enters and leaves the gen dam is typical of the Delta works. It is a point where its appearance in the estuary to compact the seabed, follo- estuary with the tide. Special measures had to be taken to three different water systems meet: the saltwater Grevelin- wed by the 'Jan Heijmans' which laid asphalt and dumped ensure that this reduction in tidal movement would not lead genmeer, the freshwater Krammer/Volkerak and the estuary stones, the 'Cardium' which positioned the mattress, the to a serious reduction in the difference between the high of the Eastern Scheldt, each with its own environment and 'Ostrea' to lift, transport and position the piers and the and low water levels. Partly for this reason two dams were its own function. The concrete anchor block, which was part mooring and cleaning pontoon 'Macoma'. These are very built in the Eastern Scheldt inland of the storm surge barrier. of the cableway used in the construction of the Grevelingen special ships designed for just one purpose: to construct the These reduced the area of the estuary and ensured an ade- dam, has been left as a monument to the new hydraulic storm surge barrier. New measuring instruments and com- quate tidal range despite the construction of the storm engineering techniques that have been developed. The puter programs were also developed, so that engineers surge barrier. Behind these two dams, the Oester dam and dams themselves symbolise the safety that the Delta Project working 30 to 40 metres below the surface could position the Philips dam, an area of fresh water has formed with a has brought to the southwest Netherlands. components with such precision that the maximum error permanent water level, the long Krammer/Volkerak and the would be just one centimetre. Zoommeer. Another reason for constructing the Oester and More Information Philips dams was that shipping on this important route The Cardium laid the first mattress in November 1982 and would no longer be affected by tidal movements. Further- A permanent exhibition on the Delta Project and the history the Ostrea placed the first pier in August 1983. Work pro- more, these dams prevent fresh water from entering the of flood defences in the Netherlands - the Delta Expo - gressed quickly. There were virtually no technical setbacks; salt water of the Eastern Scheldt. The size of the Zoommeer is housed in the Topshuis on the island Neeltje Jans in the only the cost turned out to be higher than expected. The was reduced by the completion of the Markiezaat dyke in mouth of the Eastern Scheldt. storm surge barrier was 30% more expensive than estima- 1983 and a canal was excavated to discharge excess fresh ted. On 4 October 1986 Her Majesty Queen Beatrix officially water from the lake into the Western Scheldt. The protec- Colophon opened the storm surge barrier. The Eastern Scheldt has tion provided by the storm surge barrier allowed the Oester remained open and flood protection has been achieved. On dam and the Philips dam to be constructed entirely of sand. Ministry of Transport and Public Works average the barrier has to be closed once a year because of Tidal currents in the estuary can largely be eliminated by Information Division storms. closing the barrier's gates. The Oester dam was completed Plesmanweg 5 - Den Haag in 1986 and the Philips dam in the following year. The Phi- june 1988 lips dam has an unusual lock complex with a salt/freshwater separation system that prevents salt water entering the Design: Dijkerman & van Waarden, Den Haag freshwater lake and fresh water entering the Eastern Scheldt whenever a ship passes through the locks. Photography: Aerocamera, Bart Hofmeester The Delta Project preserving the environment and securing Zeeland against flooding 11/3 R 08 The -08 11/14 /10 10 12 1013 11 13 40605 08 11 /19 08 10 if 08 08 0108 08 07 08 0808 12-4 05 06 05 06 PIT 05 07 05 07 the 35' 9 SWK " ABI 30' ABT 6 45' 40' The Delta Project preserving the environment and securing Zeeland against flooding 4 Countless floods The flood disaster of The sea has had many opportunities in the past 1953 claimed 1,835 lives to determine the shape of the Netherlands. The line of coastal defences shows where the water overpowered the people. Every century has witnessed floods. Many were given names, for example the Saint Aechten's Day Flood in 1288, the Saint Elizabeth's Day Floods in 1404 and 1421, the Saint Felix's Day Flood in 1530 and All Saints' Day Flood in 1570. Although the Dutch fought back, they often had to surrender large areas of land to the sea. The Verdronken Land van Saeftinghe (Zeeland Flanders), the Verdonken Land van Reimerswaal (South Beve- land) and Zuidland (Schouwen-Duiveland), for example, were all lost to the sea. On balance, during the past centuries more land has been lost than reclaimed. Floods have not been confined to particular periods or enabled to occur only by the limita- tions of technology. They have also occurred in the 20th century, for instance in 1906 and 1916. The greatest flood disaster in the coun- try's history occurred on the night of 1 February 1953. The sea surged into many polders in the southwest Netherlands, innundating some 200,000 cows, horses, pigs and other livestock 200,000 hectares of fertile farmland and flood- died and over 47,000 buildings were damaged. ing many towns and villages. The dykes were destroyed in 67 places and breached in over The dykes had not been equal to the unprece- 400. 1,835 people drowned and 72,000 were dentedly high water level of 4 to 5 metres forced to evacuate the region; more than above AOD (Amsterdam Ordnance Datum, mean sea level as defined for Amsterdam). The flood was caused by a spring tide, when excep- tionally low and high tides are produced as the influences of the sun and moon reinforce each other, in combination with a persistent north- westerly storm. The storm reached its peak in the middle of the night, and an hour of continu- ous wind force 12 coincided with the high tide. The water piled up against the dykes, spilled over the top of them and then began to wash them away. Most people were asleep when the sea overtook them. A great deal of assistance was offered from abroad. The people of the Netherlands were determined not to surrender the flooded land. Their thoughts first turned to repairing the damage and then to preventing a reoccurrence of such a disaster. They quickly resealed the The dikes break in many dykes and pumped the water out of the pol- Astronomical tides VLISSINGEN places ders. The experience they had gained in 5m pumping the island of Walcheren dry after the 4m bombing of its dykes in 1944, in damming the 3m Brielse Maas in 1950 and in damming the 2m Braakman inlet in 1952 proved invaluable. 1m Caissons, large watertight concrete structures, N.A.P. were indispensable as a means of blocking off 1m the channels quickly. The last breach, near 2m Ouwerkerk, was resealed in November 1953. 3m O 4 8 12 16 20 0 4 8 12 16 20 0 4 8 12 UUR 31 JANUARI 1 FEBRUARI 2 FEBRUARI Graph showing changes in water levels 1953 5 The attractions of delta regions People have always been attracted to coastal However, the human settlement, transporta- regions. River estuaries in particular are obvious tion, agriculture, fishing, trade and industry that places for settlements; the river provides a flourish due to the favourable conditions of the communication route to the hinterland and also delta are a threat to the ecosystem. The increa- supplies alluvium that forms fertile soil. The sing size of ships requires the dredging of distributaries that branch from a river as it deeper navigation channels and the construc- approaches the sea often form a triangular tion of larger harbours. Industry discharges shape on the map. The mouth of the river Nile waste into the water, and toxins discharged in Egypt is a very good example of this. The hundreds of kilometres upstream eventually he mud flats are a ancient Greeks called the mouth of the Nile a settle with the alluvium at the mouth of the eeding ground for "delta" after the fourth letter of their alphabet, wading birds river. Human activities put the ecosystem under which was written in the form of a triangle. pressure. Since the beginning of the 1970s there Nowadays the term delta is widely used to has been a growing awareness that this pres- describe many areas where a river enters a sea sure cannot continue to increase unabated and or a lake. Apart from the Nile, other famous that a balance needs to be struck between the deltas include those of the Ganges, the Missis- interests of ecology and the economy. sippi, the Rhone and the Yangtze. In the south- west Netherlands the estuaries of the Rhine, Maas and Scheldt also form a delta. Low, flat deltas are vulnerable regions, and the inhabitants have good cause to construct dykes and embankments to protect themselves against the sea. As villages and towns flourish, though, and their economic importance as centres of trade, shipping and industry increases, the need to construct better forms of protection also increases. Deltas often provide many of the conditions needed to support a rich and varied system of plant and animal communities. Algae and plants grow in the shallow, relatively warm water, which light can penetrate easily. Their growth and the supply of organic matter from the sea and minerals from the river enable deltas to act as nurseries for young fish. The driving force behind the delta's ecosystem is the tide. The regular exposure of mud flats and sandbars at low tide and their submergence at high tide is indispensable to the innumerable shellfish, ds abound in the worms and other fauna that live on them. These Dutch delta in turn are essential to the thousands of birds od chain in the that feed on them at low tide. The lower astern Scheldt animals and birds form a small food chain, one oyster, a popular of the many that exist in the water, the mud cy from the waters flats and the higher-lying salt marshes. of the delta 6 Securer flood defences Shortly after the 1953 flood a specially In 1958, Parliament passed the Delta Act, which appointed committee presented proposals for set out plans to ensure the safety of the south- the prevention of another disaster in the west Netherlands, to the great enthusiasm of future. The proposals centred on improving the public. In addition to reducing the risk of safety by strengthening the coastal defences. A flooding by increasing the height of the dykes proposal to shorten the length of the coastline and shortening the coastline by 700 kilometres, was enthusiastically received, as, after all, the the Delta Project would also create consider- strength of a defensive line increases as its able economic benefits. It would improve water length decreases. This has been the principle management in a large proportion of the behind many other hydraulic engineering Netherlands and combat the penetration of salt works, an outstanding example of which is the water into the ground water. Freshwater lakes Barrier Dam which was constructed in 1932 would form and be an important source of across the mouth of the Zuyder Zee, now called water for farms. New recreational areas, parti- the Isselmeer, to protect it from the incursions cularly for water sports, would be created. The of the North Sea. By constructing this single construction of dams would also considerably dam, the length of the coastline was reduced improve the road network in the southwest by 300 kilometres and the danger of flooding in Netherlands. a large area of the country was entirely elimi- nated. One of the Project's drawbacks was that the The committee recommended that the tidal saltwater fishing industry and the shellfish channels in the Rhine, Maas and Scheldt Delta farms would disappear. The oyster and mussel should be dammed near the coast and that the farms centred on the town of Yerseke were an dykes along the sea and the rivers in the rest of important source of income in the Eastern the country should be raised to allow for a Scheldt region, but would be destroyed after water level of five metres above AOD at the the inlets were dammed. Shellfish cultivation Hook of Holland. This would reduce the fre- would have to be transferred to other areas. In quency of inland flooding to an average of those days very little consideration was paid to once every ten thousand years and flooding in the environment; flood protection and the the inlets to once every four thousand years, economy were the main issues. which seemed quite safe enough for the time being. The New Waterway and the Western Scheldt had to be kept open to shipping due to their economic importance to the ports of Rotterdam and Antwerp. The surrounding dykes would therefore also be raised to the same height as those in the Delta. The sea walls must be able to hold back water levels of 5 meters + Normal Amsterdam Level (NAP) Oyster beds in Yerseke New water sport areas created by the Delta Plan 7 Fewer dykes The original plans for the Delta Project entailed the construction of huge dams in four tidal inlets, the Veerse Gat, the Eastern Scheldt, the Brouwershavense Gat and the Haringvliet, which would reduce the length of the sea- dykes in the region from over 700 kilometres to just 25 kilometres. In addition, three dams were also planned further inland in the Volkerak, Grevelingen and Zandkreek channels. The Volkerak dam would separate the freshwater and saltwater environments, and the dams in the Grevelingen and Zandkreek would elimin- ate uncontrollable currents in the tidal area. (rammer locks in the Some unusual civil engineering structures Philips Dam would be needed for specific purposes. A storm rds eye view of the surge barrier was to be built in the Hollandse estern delta area IJssel to protect the low-lying but densely- populated region of South Holland. A large sluice complex was to be built in the Haringvliet dam to discharge any excess water from the Rhine and the Maas into the North Sea. Locks were also to be built in several dams for commercial ships and pleasure craft. 8 New techniques The Delta Project was a challenge to Dutch Prefabrication became a common technique hydraulic engineers. It was evident that past and in addition to new materials, new equip- experience and existing techniques would not ment was also very valuable. Sluice caissons be sufficient to enable dams to be constructed were developed. A cableway with gondolas was across the wide and deep tidal channels. The developed to tip stone into the channels. tidal range in the Delta is approximately three Hydrodynamic study techniques were refined metres and the water flows in and out twice a by developing laboratory tests. The computer day with powerful currents shifting enormous gradually made its entrance. Measuring techni- quantities of sand. Weather conditions in the ques and weather forecasts became more estuaries are often unfavourable and North Sea accurate. The Delta Project would take 25 years storms produce powerful waves. New techni- to complete. A new age was dawning for ques had to be developed quickly so that the hydraulic engineering. Delta Project could be carried out. The towering caissons were adapted and improved. Man-made fibres were used for the first time to protect the seabed and to clad the dykes. The traditional seabed protection method, which involved covering the seabed with large osier mats made of willow wood and weighted with stone, was gradually replaced. Changes took place step by step. It was decided Scale model in the hydro- to implement the Delta Project by working dynamic laboratory from small to large so that technological Model of storm flood progress would keep pace with the growth in barrier currents experience. The implementation of the Delta Project The storm surge barrier in the Hollandse IJssel 1958 The implementation of the Delta Project began with the construction of a storm surge barrier across the river the Hollandse IJssel, which forms an open passageway to the sea via the Nieuwe Maas. The barrier was built just to the east of Rotterdam and completed in 1958. It protects the lowest-lying region of the Netherlands from flooding. The 80 metre wide barrier consists of four piers towering over 44 metres above AOD, two gates suspended between the piers, a shipping lock and a road bridge. Under normal conditions the gates are raised high above the water so as not to impede shipping, but when the water level is dangerously high they can be lowered, effectively damming the river. When the barrier is closed ships can pass through the lock. torm flood barrier in the Hollandse IJssel 10 The Zandkreek dam 1960 The Delta Project really got underway with the construction of the dams. First on the agenda was the Three Islands Project, which would connect the islands of Walcheren, North Beveland and South Beveland with each other. Work began in 1959 on a dam with a lock between North and South Beveland in the Zandkreek channel. The 830 metre long dam was constructed using caissons and completed in May 1960. By this date the construction of the dam across the Veerse Gat between Walcheren and North Beveland was progressing well. Around 70 million m³ of water flowed through the Veerse Gat with each tide. The Zandkreek Dam with lock The Veerse Gat dam 1961 A new technique was needed to dam the Veerse Gat. The usual caissons were adapte and what are known as sluice caissons wer Veerse Gatdam developed. Sluice caissons have sealable caisson is almost openings so that at first water can flow at the Veerse Gat through them freely while a dam is being Dam constructed. Seven sluice caissons, each a pen caisson being high as a seven-storey building, were placed sported to the last the 320 metre wide channel on a sill made in the dike tipped stone. The dam was completed in Ap 1961. The sluices were closed at slack wat between low and high tide. The closure of ti first inlet had been completed and a lake, tl Veerse Meer, had been created. A dyke was quickly laid over the caissons to finish the work. ITALIE 12 10 The Grevelingen dam 1965 A start had been made in 1958 on the six- kilometre dam across the Grevelingen channel between Schouwen-Duiveland and Goeree- Overflakkee, which would ultimately incorporate a lock and harbours near Bruinisse. A substantial part of the dam was constructed on the Oude Tonge sandbar using the well-tried method of dredging sand. Two channels remained open. The small southern channel was dammed using solid caissons placed on a sill constructed from new materials - nylon and mastic asphalt. A new method was used to dam the larger, northern channel: a cableway with gondolas suspended from steel cables nine centimetres thick was spanned across the channel and used to gradually dam it by tipping 170,000 tons of Cableway above stone. The dam was completed in 1965 and a Grevelingen road along the top opened to traffic. assageway through the Grevelingen Dam Bulldozers and diggers on the future Grevelingen Dam 13 The Volkerak locks The Volkerak dam 1969 Taking advantage of the new techniques, the Volkerak channel between the Haringvliet and Hollandsch Diep channels was dammed to improve water management and the transport network. The work, which commenced in 1957, consisted of a dam across the Hellegatsplaten (a series of sandbars) and the Hellegatsplein (an artificial island), a bridge spanning the 1200 metres across the Haringvliet, and a large lock and sluice complex and a solid dam at the mouth of the Volkerak. The dam across the Hellegatsplaten and Hellegatsplein, the Hellegats dam, was constructed entirely of sand. The Volkerak was dammed in the spring of 1969 using 12 sluice caissons. By that date the locks, built near the town of Willemstad, were already being used by ships on the busy Scheldt-Rhine shipping route. 14 The Haringvliet dam 1971 It took 14 years to construct the Haringvliet dam, which extends 4.5 kilometres between Goeree and Voorne. A unique design was developed as the dam had to remain open for the purposes of water management and the discharge of excess water from the Maas and the Rhine: a sluice complex with a channel width of 1,000 metres and a lock for fishing boats. The 17 sluices can be closed with steel gates on both the sea and the river side. The gates were made in an excavated construction site surrounded by an encircling dyke - similar to a polder - in the middle of the Haringvliet. The sluice complex temporarily functioned as sluice caissons, and the dam was completed in 1970 by tipping 100,000 concrete blocks using a cableway. A road built along the dam was opened in 1971. Trench with Haringvliet sluices under construction Drainage sluices in the Haringvliet Dam 15 Brouwers Dam Cableway at the Brouwershavense Gat The Brouwers dam 1971 The final rehearsal for the last part of the Delta Project, the Eastern Scheldt, was the construction of a dam across the 6.5 kilometre wide and 30 metre deep Brouwershavense Gat between Goeree and Schouwen. Work began in 1962 using various well-tried methods. Sand dams were dredged on the shallow Kabbelaarsbank and Middelplaten sandbars. The northern channel, Springersdiep, was dammed using sluice caissons, which had been constructed in a special construction dock in the Grevelingen. The southern channel, the Brouwershavense Gat, was dammed using the cableway method. The dam was completed at the end of 1971, creating a new lake, the Grevelingenmeer. A sluice was built into the dam ten years after its completion in order to flush the Grevelingenmeer with water from the North Sea to keep the salt content of the lake at an appropriate level. 16 The most difficult project The Eastern Scheldt dam, 1986 According to the original plans the dam across the mouth of the Eastern Scheldt inlet would have been completed in 1978, 25 years after the flood disaster. The construction of this dam, extending eight kilometres between Schouwen and North Beveland, would be the most difficult part of the Delta Project. The inlet had an average tidal range of three metres and its deepest channel was 40 metres deep. 1,100 million m³ of water flowed through the channels at each tide, considerably more than the 350 million m³ that flowed through the Brouwershavense Gat. Work commenced in 1967. The construction islands Roggenplaat, Neeltje Jans and Noordland were built on three shallow sandbars. Neeltje Jans and Noordland were later linked to each other by a three-kilometre dam. Approximately five kilometres of the dam had been completed by the end of 1973. Three channels remained open, the Hammen, Schaar van Roggenplaat and Roompot channels, with a total width of three kilometres. According to the plans they were to be dammed using the cableway method and prefabricated concrete blocks. Steel towers for the cableway had already been erected in the channels, but they were never to be used. There was an increasing body of public opinion in the Netherlands which felt that the Eastern Scheldt should remain open to conserve the environment and the fishing industry. Social pressure forced though a radical change in the Delta Project. SCHOUWEN HAMMEN ROGGENPLAAT SCHAAR VAN ROGGENPLAAT NEELTJE JANS DAMVAK GEUL NOORDLAND Roompot lock ROOMPOT Tidal channels NOORD BEVELAND and damextensions in the Eastern 0 1500m Scheldt Increasing environmental awareness The technical progress that had been achieved during the implementation of the Delta Project had not occurred in isolation. There had been a general and rapid growth in the economies of the western industrialised nations. Standards of living and levels of consumption had increased. HILMONE The growth of opportunities, knowledge and power seemed to know no bounds. Cities were expanding, the road network was growing Sting-ray constantly, communications links were bringing far-away places closer to home and man was walking on the moon. With its emphasis on flood protection, increases in scale and the use of the very latest techniques, the Delta Project was a part of this era. In the second half of the 1960s opinions about the environment changed. There was a growing awareness that the global assault on the envi- ronment could have catastrophic results. The idea gained ground that there had to be limits to growth, and the optimistic view of the future began to fade. This ultimately led to a fresh approach being adopted for the Delta Project. The construction of a solid dam across the mouth of the Eastern Scheldt lost the general support it had once commanded. If the dam were built, the Eastern Scheldt would no longer be a tidal inlet, the salt water would become fresh and instead of rising and falling with the tides the water level would be con- stant. Moreover, the plant and animal commun ities would be transformed and the shellfish would disappear. More and more people realised that the Eastern Scheldt was an area of exceptional value and became concerned about the effects that damming the inlet would have on the flora and fauna. Scientists, nature conservationists and fishermen spearheaded the protest against a solid dam. Their alternative was to raise the height of the surrounding dykes. Politicians initially refused to consider the plans. They had promised to dam the Eastern Scheldt, and they would keep their word. The fight to keep the Eastern Scheldt open, however, gradually received wider support, even in political circles. How people believed the inlet should be made safe became a yardstick for measuring their environmental awareness. The government decided to commission a special committee to perform a new study. In 1974 the committee The Eastern Scheldt recommended a compromise: the Eastern estuary holds an Scheldt should be kept open most of the time abundance of lobster but closed whenever there was a risk of flood- emonstration against ing. plans to seal off the Eastern Scheldt completely Hermit crab Seals return to the astern Scheldt estuary 18 Unique wildlife area The Eastern Scheldt is a rich and unique wildlife The Eastern Scheldt is a nursery for fish such as area. It is a tidal inlet entirely free of the in- sole, cod, plaice and herring, which breed else- fluence of freshwater rivers and is thus com- where but grow in the tidal inlet, and also a pletely saline. The tides generate fast-flowing breeding ground for others such as gar, currents as the water from the North Sea flows anchovy and pout. There are over 75 different into the inlet through channels up to 40 metres species of fish in the inlet. The Eastern Scheldt deep and two kilometres wide. Sandbars and enjoys an international reputation for its bird- shallows lie between the channels. In the more life. Many thousands of birds rest there during inland section of the Eastern Scheldt the chan- migration or come to spend the winter, the nels become narrower and shallower. The clean summer or the breeding season. There is an water, with its high salt content and relatively abundance of food; the water is pure and rarely warm temperature, provides unusual condit- freezes in winter. The area is particularly impor- ions. tant for water birds. The Eastern Scheldt is home to ducks, geese, oystercatchers, plovers All kinds of plants and animals that usually live and avocets. Many rare plants and animals live only in more southerly climes can be found in on the bed of the inlet. There are also mussels the Eastern Scheldt. The ecosystem is highly and oysters, which are economically very impor- developed, with many organisms, both common tant. and uncommon. Many valuable species of flora and fauna live on the stone and concrete-clad dykes, for example lichens, snails, sea acorns, sponges, anemones, crabs and starfish. There are dozens of varieties of seaweed, including some rare ones. The Eastern Scheldt is a rich store of food, plankton being the most impor- tant resource. A million tons of vegetation is produced each year, most of which sinks to the bottom where creatures living on the bed take full advantage of it. In their turn, fish, crusta- ceans and birds feed on the creatures living on the bed. irds on the salt marshes Sea anemone Mussels 19 Along the edges of the Eastern Scheldt there are extensive mud flats, which appear to be barren but are in fact teeming with life. Birds in particular take advantage of them. Towards the dykes, where the mud flats have gradually silted up, salt marshes have formed. Saltwater plants grow on the undulating land between the low and high tide marks, which is drained by count- e surface area of salt less streams. Some sections of the salt marshes rshes and mud flats in the Eastern Scheldt are so high that they are submerged only uary is reduced by the during spring tides. There is a rich and colourful storm flood barrier diversity of plants. Glasswort and sea aster are harvested for human consumption. A few of the salt marshes are grazed by sheep. The salt marshes form one of the few natural land- scapes remaining in the Netherlands. This too is one of the unique features of the Eastern Scheldt. 20 The half-open dam At the end of 1974 Parliament recognised the importance of keeping the Eastern Scheldt open and decided to change the plans for the Delta Project. It was not an easy decision to take and there were many opponents to it, so a compromise had to be reached. The plan for a solid dam was abandoned and the engineers were requested to design a reliable method of protection that would also preserve the valu- able environment. A design for the half-open dam had to be worked out subject to several conditions: it had to be technically feasible; the additional costs had to be kept to a minimum; and the area around the Eastern Scheldt had to be protected from flooding by 1985. The hydraulic engineers were confronted with an entirely new problem, one at the very limits of their technical know-how. As there would no longer be a dam by 1978, the government provided funds to reinforce the weak dykes Creation of pitchings on bordering the inlet. The reinforcement of the the dike dykes considerably improved the safety of the area before the new barrier was completed. Pushing back the frontiers The engineers' problem was to design and con- placed in the three channels, Hammen, Schaar struct a reliable, open barrier that would allow van Roggenplaat and Roompot, and firmly the tide to enter the Eastern Scheldt each day. anchored with masses of stone, and 62 steel Such a project had never been carried out gates that could be raised or lowered would be anywhere in the world. The knowledge and placed between the piers. Under normal condit- experience gained during the implementation ions the gates would be raised SO that the tidal of the previous parts of the Delta Project were movement in the inlet would be largely no longer sufficient and there was little time retained, thus preserving the environment. The available. Of the various solutions that were gates would be lowered during storms when proposed the engineers decided on a storm exceptionally high waterlevels were expected, surge barrier across the mouth of the Eastern damming the Eastern Scheldt from the North Scheldt. Parliament agreed to the project in Sea and guaranteeing protection from flooding. mid-1976. The idea behind the storm surge barrier was simple: 65 concrete piers would be As the storm surge barrier would reduce the tide to some extent, it would be necessary to compartmentalise the Eastern Scheldt by build- Location of the ing dams inland of the barrier. This would compartimentalisation works reduce the tidal area so as to maintain a suffic- ient difference in level between high and low tide, namely an average tidal range of 3.2 metres at Yerseke, which was important for the fishing industry. It also guaranteed that the Scheldt-Rhine shipping link would be non-tidal, as the Netherlands government had promised Belgium. Compartmentation had the additional advantage of separating salt water from fresh water, which was desirable for efficient envi- ronmental conservation and water manage- ment. Freshwater peripheral lakes were formed behind the Philips dam in the northeast and the Oester dam in the southeast. A discharge canal was dredged, leading to the Western Scheldt, to control the level and quality of these lakes. For technical and environmental reasons a further dyke was constructed near Bergen op Zoom, which also created a new lake. The final part of the compartmentation works made the canal through South Beveland suitable for pushed barges. 21 Step-by-step construction The storm surge barrier was constructed step The barrier is very heavy and the seabed had to by step. Solid foundations were needed in the be compacted to a depth of 15 metres using a sandy bed of the Eastern Scheldt, where enor- specially designed vessel, the Mytilus, to mous quantities of sand are continuously being increase its bearing capacity. The Mytilus drove moved, changing the location of sandbars and four steel tubes into the bed, which were channels. The bed where the piers were to vibrated to force water out from between the stand had to be improved. The first operation grains of sand, eliminating quicksand and thus was to lay block mattresses made of concrete strengthening the bed. It took three years to blocks attached to polypropylene sheets to compact the bed in this manner. Bed protec- protect the seabed around the area where the tion, improvement and depth compaction, piers were to stand. At the site itself, clay strata however, were not enough to ensure that the were were dredged out and replaced with sand piers could be placed safely. A foundation had covered with a layer of gravel to prevent it to be constructed on the reinforced bed to from being scoured out during storms. prevent the sand from being washed away and to guarantee that the piers would stand evenly. The Mytilus sea-bed compression vessel 22 Polypropylene mattresses Polypropylene mattresses filled with graded layers of gravel were used in the foundations. They were made at a factory that had been specifically built for their production. Two kinds of mattresses were made, lower mattresses 200 metres long, 42 metres wide and 36 centi- metres thick, and upper mattresses measuring Mat factory on the Neeltje Jans artificial 60x31 metres. 65 mattresses of each kind were island needed. As the mattresses were produced in the factory they were rolled onto huge floating drums and then placed on a specially-designed vessel, the Cardium, which laid them. The seabed was first levelled using the extra-wide suction nozzle on the bow of the Cardium before the vessel rolled the mattresses into position. It sounds a simple operation, but the mattresses had to be laid with extreme preci- sion, which is not so simple in a turbulent tidal inlet. Furthermore, they could only be laid during the short period of slack water between low and high tide, which lasts for just one hour. If a mattress had not been fully unrolled before the tide turned, it would have been destroyed by the force of the ebb tide. Fortunately, this never occurred. When the mattresses were being laid the Cardium was assisted by another specially- designed vessel, the Jan Heijmans. This vessel held the ends of the mattresses in place and sealed the seams between them with layers of stone. The piers were placed 45 metres apart, so there was a three-metre seam between them and the 42 metre wide mattresses. Laying the mattresses was a critical stage in the con- struction of the storm surge barrier: it deter- mined the evenness of the seabed and the strength of the barrier. The Cardium mat-laying vessel with the The mattresses are filled with graded layers of lan Heijmans stone and asphalt tipper sand and gravel and act as filters, trapping the sand in place on the seabed but allowing water The Cardium rolls off to flow through them. The mattresses were laid a mat quickly. In some sections a block mattress was laid on top of them to smooth out any uneven- ness. Another special mattress, a gravel ballast mattress, was finally laid over the seams to prevent the stone from being washed away. The final result was a flat "carpet", more level than most football pitches, across a 200 metre section of the mouth of the Eastern Scheldt. 23 The backbone of the barrier The 65 enormous piers from the backbone of the barrier. They were constructed in three large construction docks 15 metres deep, which were kept dry by 320 underwater pumps. The piers are colossal structures made of pre- stressed concrete to keep their weight to a minimum. They are 30 to 40 metres tall and have a dry weight of up to 18,000 tons. The height of the piers depended upon their ultimate position in one of the channels. A purpose-built factory produced 450,000 m³ of concrete over four years. The piers were hollow and were filled with sand when they erial construction of pillars were in position. They are not featureless monoliths but contain many notches and inden- ars in a building dock tations where the other concrete components and the steel gates are attached. It took just under one and a half years to construct each pier. As all the piers had to be completed in only four years, they were produced in stag- gered batches with work beginning on a new pier every two weeks. At the peak of activity 30 piers were being constructed simultaneously. 24 Unusual vessels When all the piers in a construction dock were Work on the piers was far from over once they completed, the dock was flooded and the had been placed. They still needed to be grou- encircling dyke was opened so that they could ted, which involved filling the space between be transported to one of the channels in the the foot of the pier and the foundation mouth of the Eastern Scheldt. This operation mattress with grout, a mixture of sand, cement too required unusual vessels. The Ostrea was and water, to achieve a perfect bond with the designed and built to lift the piers in the con- mattress. Once this operation was completed, struction dock, transport them to the channels the lower sections of the piers were filled with and then place them with great precision on sand to increase their stability. They were then the mattresses. The Macoma was specially built covered with a layer of concrete to protect to moor the Ostrea while it was placing the them from damage. The foot of the piers was piers and to clean the site immediately before- protected by stone/asphalt bags, each weighing hand. The piers were positioned with pin-point 30 to 40 tons. These were necessary as each accuracy at slack water using very sophisticated pier had to be embedded in a sill made of The Ostrea crane vessel measuring equipment. It took a year to place dumped stone. and the Macoma them all. mooring and cleansing pontoon shortly after a pillar has been installed The turn of the tide, the right time to install the pillars Ten-ton stones The sill increased the piers' stability and also helped dam the mouth of the Eastern Scheldt The ultimate intention was that only that part of the barrier which could be closed by gates was to remain open. The sill was constructed of graded layers of stone. Lighter stones were placed at the bottom and huge blocks weighing as much as ten tons (10,000 kilogrammes) were placed on top. These blocks have to be so heavy in order to withstand the powerful currents that would build up if one of the gates refused to close during a storm. The largest stones could not be dropped into position as the risk of their damaging the piers was too great. The Trias was therefore designed to lay the top layer of stone. This vessel was equipped with a large crane with a long extendable arm that was used to place the heavy stones accurately. Five million tons of stone were used in the con- struction of the sill. It had to be imported over a period of four years from Germany, Finland, Sweden and Belgium as it was not available in the Netherlands. When the work on the foundations, the piers and the underwater sill was finished, a large part of the battle had been won, although there was still a lot of work to be done to complete the barrier. In order of assembly, service ducts, pier capping units, gates, sill beams and upper beams had to be installed. These are all indispensable components for the Stone deposits at the dge of the storm flood efficient operation of the storm surge barrier. barrier The concrete service duct, each section of which was 45 metres long, was placed on the The Trias top-layer ipping vessel in action piers by the floating crane Taklift 4. A major road now runs over the top of the service duct, e Taklift IV crane vessel while part of the space inside it has been used with a road bridge box girder in its hoist to house the operating and control equipment for the gates. Ever increasing currents The capping units were made of prestressed concrete and were installed to increase the height of the piers to accommodate the gate structure. The height of the 124 upper members varies from 4.3 to 10 metres and their weight from 250 to 450 tons. 62 concrete sill beams - hollow box girders 39 metres long, 8 metres wide and 8 metres high were built in a con- struction dock to connect the piers to each other under water. After they had been posi- tioned between the piers, thus reducing the cross section of the channel and causing the speed of the current to increase, they were filled with sand. Above the water level the piers were connected to each other by concrete upper beams, which form the upper limit of the opening in the barrier. The steel gates were designed to hold back the Between the dam and the pier lies a quarry waters of the North Sea during storms. Their stone dam height varies from 5.9 to 11.9 metres depending upon their position in the barrier. The largest stallation of sill beams gate, weighing 480 tons, is located in the in trench deepest channel, the Roompot. The gates were he Taklift hangs a lock installed between the piers using the Taklift 4. hatch in place When the gates are raised the Eastern Scheldt is Positioning of lock open and sufficient water can flow into it to atches is precision work ensure a tidal range of 3.2 metres at Yerseke, the centre of the shellfish industry. That is just over three-quarters of the original tidal range and enough to preserve the existing wildlife and the fishing industry. 27 Gates closed The gates consist of plating and tubular steel girders. The plating, which is on the Eastern Scheldt side, needs to be just one centimetre thick to withstand storms. The gates have been designed to resist the loads caused by different water levels on either side and can be raised or lowered in fast flowing water under adverse weather conditions. Each gate is opened or closed with the aid of two hydraulic cylinders, varying in length from 21.8 to 34.5 metres. The gates can be moved at a speed of three milli- metres per second, which means that it takes an hour to open or close the largest gate. The storm surge barrier is operated from the Tops-huis, the central control building standing high above the North Sea at some distance from the barrier. On average the barrier has to be closed once a year due to extremely high water levels. The Tops-huis also accommodates the Delta Expo, a permanent exhibition on 2,000 years of hydraulic engineering. On the southern part of the Neeltje Jans construction island the Roompot lock was built because ships can no longer pass freely through the mouth of The Ir. J.W. Tops-huis, the Eastern Scheldt. A road has been built on a ie storm flood barrier viaduct above the barrier. service building e storm flood barrier is On 4 October 1986 Her Majesty Queen ompletely computer- Beatrix officially declared the storm surge controlled barrier in the Eastern Scheldt open. leen Beatrix opens the astern Scheldt storm ood barrier. Standing /ith her are Transport and Public Works linister Dr. Neelie Smit (left) and J. van Dixhoorn, e Director General of Public Works zee veilig 28 Other uses The storm surge barrier was constructed to provide greater protection from the sea and to preserve the unique and valuable environment of the Eastern Scheldt. This has largely deter- mined how and when the barrier is operated, and the steel gates will be kept open whenever possible. In principle the barrier is closed only when it is predicted that the high water level will exceed 3.25 metres above AOD. A danger level has also been decided upon, as the sea is often unpredictable and the water level can rise suddenly. If the water rises above the danger level the gates will close automatically. A warn- ing system has been developed that makes use of long-range weather forecasts. Opening or closing the barrier will affect the safety of the flood defences along the Eastern Scheldt (strong dykes are still necessary) and also the environment, the fishing industry, water management and shipping. When the barrier is operated, therefore, as much account as possible will be taken of conditions in the Eastern Scheldt. The barrier can of course be operated for other purposes in addition to flood prevention. Since this could endanger the environment, however, it has been decided that when the water level is not dangerously high the gates will be closed only to prevent oil or chemical pollution from entering the Eastern Scheldt, to limit the effects of dyke collapse and to prevent drift ice damag- ing the dykes. The storm surge barrier was also closed during the construction of the compart- mentation dams in 1986 and 1987 to moder- ate the effect of the tide. Reducing the tidal current made it possible to construct the Oester and Philips dams using sand. 29 New peripheral lakes The compartmentation dams necessitated by the building of the barrier were constructed on the border between the provinces of Zeeland and North Brabant. Interconnected peripheral lakes formed as a result of the construction of the Oester and Philips dams. From north to south these lakes are the Krammer/Volkerak, the Zoommeer and the Markiezaatsmeer. A sophisticated salt/freshwater separation system has been built into the Krammer lock complex to prevent the fresh water of the lakes mixing with the salt water of the Eastern Scheldt. Water can be discharged from the Zoommeer via the Bath canal into the Western Scheldt so that the level of the peripheral lakes is kept constant. The Oester and Philips dams were constructed using sand and are the largest sand dams in the world to have been constructed in Philips Dam flowing water. The Philips dam 1987 The Philips dam was constructed between Sint Philipsland and the Grevelingen dam. A large lock complex, the Krammer locks, was built on a construction island in the middle of the dam. Two locks were built for commercial shipping and are suitable for four-barge push-tows. A separate lock was built for pleasure craft. A salt/freshwater separation system was built into the lock complex to prevent large quantities of salt water entering the freshwater Krammer/Volkerak whenever a ship is locked through from the Eastern Scheldt, and conversely to prevent dilution of the Eastern Scheldt with fresh water. It works on the principle that salt water is denser than fresh water. During the lockage of ships to the Krammer/Volkerak the salt water of the Eastern Scheldt is replaced with fresh water, and the procedure is reversed for ships travelling in the opposite direction. This system has also been used in the Kreekrak locks to prevent the brackish and polluted water from the industrial area around Antwerp entering the Zoommeer. 30 10 The Markiezaat dyke 1983 A special dyke had to be constructed to prevent strong currents building up during the construction of the Oester dam, which would have caused problems for shipping and weakened the banks. This dyke was built along the edge of the submerged former marquisate of Bergen op Zoom; hence its name, the Markiezaat dyke. A serious set-back occurred during the construction of this dyke, which extends five kilometres between the Kreekrak locks and the Molenplaat near Bergen op Zoom. 1982 it had been virtually Markiezaatskade quay completed and only the finishing work needed to be done when a storm surge 3.7 metres above AOD breached the dyke. The dyke was finally completed a year later. A freshwater lake has formed behind the Markiezaat dyke, most of which will remain a wildlife area. The Oester dam 1986 The Oester dam was built between Tholen and South Beveland. Extending nearly 11 kilometres, it is the longest of all the dams in the Delta. It separates the Scheldt-Rhine shipping route from the Eastern Scheldt, so that this important link is now non-tidal. The dam lies close to the Scheldt-Rhine link in the most easterly section of the inlet and therefore the majority of the Eastern Scheldt remains tidal. A lock, the Bergsche Diep lock, has been built in the dam near Tholen for pleasure craft and fishing boats moving between the Zoommeer and the Eastern Scheldt. The dam was built in an area where man had often done battle with the sea in the past. The composition of the bed was so erratic that it had to be improved in many places. he Oester Dam with the Bergse Diep lock 31 A simple technique A sluice has been built in the Grevelingen dam just south of the point where it meets the Philips dam. It uses a simple principle: that of the siphon. It does not need expensive gates. The siphon allows water to flow between the Grevelingenmeer and the Eastern Scheldt. The siphon and the discharge sluice in the Brouwers dam enable the Grevelingenmeer to be flushed with water to keep its salt content at an accep- table level. Water from the land inland of the compartmen- tation dams drains into the peripheral lakes and the level and quality of these lakes have to be controlled. Inlet sluices have been constructed in the Volkerak dam and when necessary water from the Rhine and Maas can enter the peri- pheral lakes via the Hollandsch Diep. As there are often toxins in the rivers, though, the river water is only rarely allowed to enter the peri- pheral lakes; otherwise the beds of the Kram- mer/volkerak and the Zoommeer would be covered with a layer of highly polluted alluvium. The Bath Discharge Canal 1987 The eight-kilometre Bath discharge canal has been excavated across the neck of South Bathse drainage sluice Beveland to discharge excess water from the The mouth of the canal rivers and polders. It runs parallel to the running through Zuid Scheldt-Rhine link and can discharge 8.5 Beveland at Hansweert million³ of water per day. At the outlet in the Western Scheldt there is a sluice made of concrete tunnels that forms part of the sea wall. The sluice gates are closed when the water level in the Western Scheldt is high, thus preventing salt water from the Western Scheldt entering the Zoommeer. The existing canal running through South Beveland was also improved as part of the compartmentation works. New locks were built at Hansweert, the canal was widened and a lock-free mouth was created near Wemeldinge. 32 The Delta project completed The bold programme of hydraulic engineering The Netherlands was willing to spend a lot of works in the Delta produced enormous changes money on the Delta Project. The cost of ensur- affecting people, animals, plants and the land- ing protection from flooding, radically improv- scape. Dams, locks and roads were constructed ing the communications network, distributing and new lakes and residential and recreational the scarce supplies of fresh water more effi- areas were created. Sweeping changes have ciently and preserving the unique ecosystem occurred in the age-old rhythm of ebb and came to Fl. 12,000 m. The work in the Eastern flow. The environment has altered in many Scheldt was the most expensive part of the places and in many ways. In addition to protect- Delta Project, costing Fl. 8,000 m. ing the southeast Netherlands from flooding and producing economic benefits, the imple- During the official opening ceremony of the mentation of the Delta Project increasingly took storm surge barrier, Queen Beatrix declared the account of ecological requirements. A delta is a Delta Project completed. The work in the south- very rich and varied system of plant and animal west Netherlands may be over, but there is still communities: an ecosystem that is also econo- a lot of work for the hydraulic engineers. Shal- mically important and very sensitive to human lows and sandbars are developing in front of intervention. the dams and headlands, and gradually becom- ing higher, promoting the formation of new channels. This area can offer new opportunities to the fishing industry and the environment. Plans are therefore already under consideration in connection with the Delta Project for the future of this area. The steady rise of the sea level also indicates that the protection of the Netherlands against the sea will remain a permanent struggle. Dutch hydraulic engineers believe that the knowledge and expertise they gained in the thirty years it took to complete The last lock hatch is put in place the Delta Project should also benefit other countries in addition to the Netherlands. The storm flood barrier is complete Colophon Ministry of Transport and Public Works Information Division Plesmanweg 5 - Den Haag January 1989 D67 Design: Dijkerman & van Waarden, Den Haag Photography: Aero camera Bart Hofmeester, Willem Diepraam, Peter de Ruig, Delta-phot, Rijkswaterstaat reprografie en Aeroview Lithography: Duolitho b.v., Zoetermeer Printed: De Lange van Leer, Deventer Voet Meters vm Feet Metres Fms 0 1 2 3 4 5 6 7 95 85 90 80 65 75 60 70 55 50 40 45 25 20 35 30 10 15 5 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 15 16 13 14 12 11 10 8 9 6 7 5 4 2 3 O 1 24 25 26 27 28 29 NW 7 03 90 Is 03 05 RO1 90 07 05 05 07\ The compartmentalisation works in the Eastern Scheldt for the benefit of the natural environment, water management and shipping GOEREE- LAKE OVERFLAKKEE GREVELINGEN VOLKERAK SCHOUWEN, INLET SLUICE DUIVELAND PHILIPS DAM ST.PHILIPS LAND NORTH BRABANT THOLEN EASTERN SCHELDT The storm surge barrier in the Eastern Scheldt LAKE MARQUISATE OESTER DAM MARQUISATE QUAY SOUTH BEVELAND WESTERN SCHELDT BATH DISCHARGE CANAL TIDAL SALT STAGNANT SALT FRESH Location of the compartmentalisation works The construction island in the Krammer with locks, approach harbours and water reservoirs. The compartmentalisation works in the eastern scheldt for the benefit of the natural environment, water management and shipping The original scenario for the Delta Project envisaged the damming of all the estuaries, distributaries and waterways open to the sea in the south-west of the Netherlands with the exception of the New Waterway and the Western Scheldt, which would remain open for shipping. The dams were to protect the hinterland from storm surges such as the one which took such a heavy toll of lives and property in 1953. The Eastern Scheldt was also to be closed off by a dam 9 kilometres in length, creating a freshwater lake which would have incorporated the Krammer and the Volkerak. But in the early seventies public demand for the conservation of the existing natural environment in the Eastern Scheldt was SO great that the government decided on a change of plan. A storm surge barrier which can be closed as occasion demands has now been constructed. Under normal conditions, the 62 steel gates remain open to permit virtually normal tidal movement, but if storms give rise to the threat of excessively high water levels the gates can be closed until the danger passes. In this way the valuable natural environment in the Eastern Scheldt area can be conserved, fishing activities can continue unhindered and, at the same time, the population of this part of the Netherlands is protected from the hazards associated with extreme weather conditions. The decision to build the storm surge barrier also embraced the construction of two compart- mentalisation dams in the eastern section of the estuary, the Philips dam in the north-east, and NORTH SEA ROTTERDAM the Oester dam in the south-east, enclosing a HARINGVLIET freshwater peripheral lake. A discharge canal linking up with the Western Scheldt was dug BROUWERS DAM with a view to maintaining the quality of the water in this lake as well as controlling water EASTERN SCHELDT levels. As part of the compartmentalisation scheme the existing canal through South Beveland is being adapted for pushed barge BERGEN OP ZOOM traffic. Underwater life A resting place and feeding area for birds An oyster farm near Yerseke Tidal movement in the Eastern Scheldt. Above: low water Fixed arch bridge over the Scheldt-Rhine link Below: high tide six hours later 2 Why compartmentalisation? EASTERN SCHELDT The compartmentalisation dams are necessary for the following reasons: a) to reduce the tidal area in the Eastern Scheldt b) to make the Scheldt-Rhine link non-tidal c) to create a freshwater buffer lake between the salt seawater section of the Eastern Scheldt and the freshwater complex in WEMELDINGE the western part of the province of Brabant and the Hollands Diep. a) To keep the cost of the storm surge barrier within certain limits the total area of the opening had to be restricted to approximetaly 14,000 m², as a consequence of which the volume of tidal flow has been reduced. Both the reduction in the difference between low and high water and the reduced velocity of the water passing through the barrier is detrimental to flora and fauna and to the important mussel and oyster industries. However, the construction of the Philips andd Oester dams has reduced the tidal area SO that the reduction in the tidal range is restricted to about 25%. A minimum range of 2.70 m at Yerseke can thus be achieved. FLUSHING PIPELINE TUNNEL b) In 1963 Belgium and the Netherlands concluded a treaty on the shipping link between the Scheldt and the Rhine which TRAFFIC BRIDGE, assured that the shipping channel would be non-tidal. At the RAIL BRIDGE design stage of the Scheldt-Rhine link, opened in 1975, provision was made for a fixed water level which would be BERGEN OP ZOOM attained when the Eastern Schelde was completely closed off (originally scheduled for 1978). If tidal movement were NATIONAL retained the fixed bridges would not be high enough to allow HIGHWAY A58 sufficient clearance for shipping at high water and at low LOCKS water the canal would not be deep enough. The two compartmentalisation dams thus ensure that the international inland shipping channels are also kept free of HANSWEERT WEST HANSWEERT EAST tidal movement. c) Apart from this a freshwater lake is necessary: it is important to both water management and environmental management OUTER APPROACH that the salt water of the Eastern Scheldt should be HARBOUR separated from the fresh water of the peripheral lake to the east of the dams. This prevents both salinization of the WESTERN SCHELDT hinterland and desalinization of the Eastern Scheldt. In order to control the water level and the quality of the peripheral lake, it was decided to construct a discharge canal Adaptation of the canal through South Beveland with a discharge sluice into the Western Scheldt. Shipping routes in the southern Delta area. Projected cargo figures for 1990 in millions of tonnes capacity KRAMMER LOCKS 65,7 VOLKERAK LOCKS 168 KATS LOCK 5,9 CANAL THROUGH SCHELDT-RHINE LINK WALCHEREN CANAL THROUGH SOUTH BEVELAND 57 KREEKRAK LOCKS 97 3 The Philips dam lock complex in 1979, after which further excavation work was carried out to a depth of 15 metres below A.O.D. In order to pump the site dry The extra dams built across the navigation route between 152 wells had to be dug to a depth of 47 metres below A.O.D.; Zeeland and the major rivers are an obstacle to shipping, SO the total capacity of the pumps was 6000 m3 per hour. Before locks had to be built. An artificial island was built in the Krammer work could begin the subsoil at the bottom of the site was with a lock complex and approach harbours for inland shipping reinforced to such an extent that pile-driving was not necessary. and pleasure craft. There are two locks 280 metres long and 24 The lock complex was the largest concrete construction work metres wide for 4-barge push-tow units. In addition there are ever contracted out by the Public Works Department two pleasure craft measuring 9 m X 75 m. The sill depth of the (Rijkswaterstaat) as a single commission. Each of the two push- push-tow locks is 6.25 metres below A.O.D. (A.O.D. = tow locks has a reinforced concrete lock chamber with the floor Amsterdam Ordnance Datum, mean sea level as defined for 3 metres thick and a perforated upper floor. In the centre of each Amsterdam). Space has been reserved for a future third push- chamber, between the two floors, there are culverts to supply tow lock if this should be necessary. Since this is a busy shipping and discharge water and these are connected to the two route it was decided to build separate locks and approach storage reservoirs and also to the adjacent section of the Eastern harbours for commercial and pleasure craft traffic. The lock Scheldt, the Slaak channel. The locks are surrounded on three complex has been furnished with a fresh/saltwater separation sides by the fresh water the peripheral lake known as the system to prevent large quantities of salt water from the Eastern Zoommeer; on the fourth side they are separated from the salt Scheldt entering the freshwater peripheral lake during locking water of the Eastern Scheldt by retaining walls built into the piers and, vice versa, to ensure that the Eastern Scheldt is kept on the seaward side of the lock. relatively free of fresh water. This ingenious system makes use of the fact that salt water is heavier than fresh water, together with a system of storage reservoirs and pumps for removing either the fresh or salt water from the locks and returning it to its original location. For the construction of the lock complex an island with an area of 96 ha. was built in 1977 and 1978 in a shallow section between the Krammer and Slaak channels. A 700 m temporary bridge was built out to the island to facilitate construction work. After the construction of a surrounding dike and a pumping station the 18 ha. construction site was pumped dry in 7 weeks Left: the Kreekrak locks in the Scheldt-Rhine link. Below: the Krammer locks in the Philips dam. unicon 5 The first phase of the construction island in the Krammer: building the dam to contain the construction harbour. The temporary bridge giving access to the construction island. The Krammer locks before and after the flooding of the construction site. The fresh/saltwater separation system EASTERN SCHELDT THE ZOOMMEER PERIPHERAL LAKE The system works on the principle that when the lock is closed the fresh water in the lock chamber is replaced by salt water, or vice versa, depending on whether the vessel is entering or leaving the peripheral lake. Obviously it cannot come into operation until the Philips dam has been completed and the salt and fresh water have been separated leaving the Zoommeer. The system includes two storage reservoirs, one of 45 ha. with a lower water level and one of 40 ha. with a higher water level. The lock chambers are connected to these reservoirs and to the Slaak channel in the Eastern Scheldt by a system of culverts and 1. ENTRY FROM EASTERN SCHELDT (SALT WATER) sluices. The lock chamber walls contain openings which can be sealed by means of sliding panels. When open they admit fresh water from the surrounding Zoommeer. This is made possible by simultaneously releasing a similar quantity of salt water through the perforated floor and via the system of outlet sluices into the lower reservoir. The salt water in the chamber is thus replaced by fresh water entering above it. If the lock chamber has to be filled with salt water, i.e. if a ship is proceeding from the Zoommeer to the Eastern Scheldt, the salt water is allowed to flow via the inlets, culverts and perforated floor from the higher reservoir into the lower section of the lock chamber. Since salt 2. SEAWARD GATE CLOSED water is heavier than fresh water there is little chance of the two mixing. The salt water forces the fresh water upwards SO that it flows through the openings in the chamber walls into the freshwater lake. In this way the chamber is supplied with salt water from below. At certain times the level of the water in the Eastern Scheldt is sufficient to perform this function and the reservoirs are not required. In order to connect each of the locks with each discharge sluice a whole network of culverts was created. The total width of the six culverts is 50 metres, while the diameter of each of these huge pipes is approximately the same as that of a railway tunnel. 3. LEVELLING OF SALT WATER WITH FRESHWATER LAKE 5.60 24.10 5.60 +7.00 4. REPLACEMENT OF SALT WATER WITH FRESH WATER A.O.D. perforated floor -7.00 12.50 12.50 5. LANDWARD GATE OPENED 31.10 Cross-section of a push-tow lock 6. ENTRY INTO VOLKERAK (FRESH WATER) Far right: construction of the pumping station in the Philips dam Locking cycle 8 SPACE FOR 3RD LOCK The water in the above network flows in accordance with the interconnected vessels principle. If only pumps were used to effect the exchange if waters between the chambers, ie, if culverts or reservoirs were not used, this would result in higher energy costs. The water in the reservoirs must be kept at the desired level. This can be done by pumping water out of the lower reservoir into the Eastern Scheldt or into the higher 2ND LOCK reservoir. For this purpose a pumping station was built with four adjustable-screw centrifugal pumps each of which can move 11.5 m3 per second. The capacity required for two locks is approximately 20 m3/sec. At high tide in the Eastern Scheldt the higher reservoir can be filled without the use of pumps simply by lowering a section of the surrounding ring dike. 1ST LOCK INLET Right: general view of the site of the pumping station and system of DISCHARGE SLUICE culverts for the locks in the Philips dam. OUTLET PUMPING STATION The system of culverts in the push-tow locks Diagram of the inlet, outlet and discharge sluices in the push-tow locks of the Philips dam PHILIPS DAM ZOOMMEER PERIPHERAL LAKE 2ND LOCK SALTWATER APPROACH HARBOUR FRESHWATER APPROACH HARBOUR 1ST LOCK HIGHER RESERVOIR LOWER RESERVOIR INLET CULVERTS OUTLET CULVERTS PUMPING STATION DISCHARGE CULVERTS EASTERN SCHELDT PHILIPS DAM 10 Wall openings and perforated floor 12 Gate-operating machinery and pumping station Wall openings and perforated floor of the locks, which form part of the fresh/saltwater separation system. 13 Pleasure craft locks These are twin locks with a dividing wall, the lock piers being 9.10 9.10 equipped with two revolving gates with an automatic locking device which prevents the gates from opening if the water level in the lock is not equal to that outside it. These locks also have a fresh/saltwater separation system, but in this case the work of the reservoirs is done by a pump linked by culverts directly with A.O.D. the Eastern Scheldt and the lock chambers. The pump has a capacity of 4 m3 per second. -3.45 -6.90 30.00 Cross-section of the pleasure craft locks The pleasure craft lock site ready to be flooded. 14 Construction of the locks drive system and rubber sealing devices. The 258 openings in the walls of the lock chamber which regulate the two-way flow Enormous quantities of concrete were required for the Krammer of fresh water can also be opened and closed by means of locks. The construction of the 280 metre push-tow locks with sliding panels. their concrete walls several metres thick, double flooring and network of huge culvert pipes called for a concrete works on the construction island itself, consisting of a conveyor system for sand and gravel, two cement silos, mooring wharfs, a hot water installation and storage tanks with metering devices for the various additives required. The concrete factory had a capacity of 230 m3 per hour, while the silos had a storage capacity of GATE 1200 tonnes. There was also a special site for storing and processing the steel for reinforcing the concrete, where 6,000 tonnes could be stored and a weekly production of 400 tonnes could be achieved. The locks were constructed in 14-metre sections poured in 5 consecutive operations. An ingenious system of shuttering was devised for this purpose which allowed LOCK CHAMBER to rapid handling SO that the shuttering would be in place ready for the following pouring operation. The power supply for the Krammer locks, 4000 kVA, is provided HYDRAULIC PRESS by the Zeeland Provincial Energy Authority whose service facility contains a high-tension distribution station and two diesel- powered emergency generators each capable of producing 725 kVA. The complex system of machinery for the variety of discharge and filling programmes required in a lock complex with a fresh/saltwater separation system is controlled by a computer GATE which performs the necessary calculations and continually RUBBER SEALING DEVICE monitors operations. Obviously, if the salt/fresh separation system is to function adequately the lock gates must seal well. The push-tow locks are equipped with hydraulic sliding gates which are constantly being forced against the wall of the lock chamber. The gates in the inlet, outlet and discharge sluices have a variable-speed Closing mechanism of a sliding gate in the push-tow locks. Cross-section and ground plan of a push-tow lock. AOD-625 m 280 m 24 m 15 Pouring the concrete for a section of a culvert. Pouring concrete for the walls of the push-tow locks in consecutive sections. 284841 Tjaden 16 Approach harbours Since the Krammer locks, like the Volkerak locks to the north- east, are situated on a busy shipping route, extensive approach harbours with a length of approximately 1500 metres were built. They were designed for a configuration with three push-tow locks, in case the third lock should ever be required, and they extend to a depth of 7 metres below A.O.D.; the width of the channel at this depth at the entrance is 150 metres. The approach harbours are enclosed by dams which were also designed to: - serve as a guide for shipping; - prevent the formation of currents in the period before the completion of the Philips dam; - reduce the intrusion of waves; - provide road links with the shore. The approach harbours are equipped with waiting berths and guide walls. Ships are guided into the lock via a queuing area and a funnel-shaped area formed by the guide walls on one side and a central guide jetty on the other. The waiting berths are for the use of shipping at the back of the queue which will have to wait for some time, perhaps even until the following day. The Zijpe approach harbour on the Eastern Scheldt is equipped with a floating guide wall to counteract tidal influence. The Volkerak lock complex HARBOUR WALL 3RD LOCK GUIDE WALL 2ND LOCK ZIJPE APPROACH HARBOUR VOLKERAK APPROACH HARBOUR WAITING BERTHS 1ST LOCK WAITING BERTHS HARBOUW WALL Location of the guide walls and waiting berths in the approach harbours at the Krammer locks The ring dike under construction 17 Bridges A 650 metre-long road bridge crosses the entire lock complex. A bascule bridge spans the northern pushed barge lock, SO that at least one of the locks offers unlimited clearance for shipping. The bridge platform consists of pre-stressed concrete beams resting on 20 concrete piles and two abutments. Each span is approximately 30 metres in length. The components of the temporary bridge have been incorporated in the permanent bridgeworks. The highest point of the bridge is above the yacht locks (clearance: 18.5 metres); the underside of the bridge at the push-tow locks allows a clearance of about 14.5 metres. The locks are provided with control rooms and a utilities block containing offices, the operating computer, transformers and the emergency generators. Once the locks had become operational the sections of the Philips dam which link the lock complex with the Grevelingen dam on one side and with St. Philipsland on the other could also be completed. The ring dike enclosing the lock complex first had to be dredged away, of course, in order to make the locks accessible to shipping. It was decided that the section of the dam between the locks and St. Philipsland should be situated well to the east in order to keep as large as possible an area of the mudflats to the north of St. Philipsland under tidal influence. Wherever possible, the connecting road on the shore has been routed SO that it avoids crossing farmland. The Philips dam and the lock complex were completed in 1987. The lock complex shortly before completion. 18 LAKE GREVELINGEN GREVELINGEN DAM KRAMMER PHILIPS DAM LOCK COMPLEX SLAAK ST. PHILIPSLAND ZIJPE The lock complex in the Philips dam Placing the prefabricated pre-stressed T piles for the bridge over the Krammer locks The utilities block at the Krammer locks. 19 The Oester dam THOLEN The second compartmentalisation dam is the Oester dam, SCHELDT-RHINE LINK situated in the eastern section of the Eastern Scheldt between Tholen and South Beveland. This dam closes off the Scheldt- Rhine link from the Eastern Scheldt. On the Tholen side of the dam there is a lock for the use of small vessels sailing between LOCK THOLEN GAP the Eastern Scheldt and the peripheral lake; this lock is 34 metres long and 6.5 metres wide and is spanned by an opening bridge. The sill depth on the Eastern Scheldt side is 4 metres MAROLLE GAP below A.O.D. and on the peripheral lake side 2.5 metres. The lock is important for pleasure craft and fishing vessels. The Oester dam crosses two navigation channels, the Tholen NORTHERN Gap and the Marolle Gap. The northern section of the dam was MARQUISATE QUAY kept well to the west, running parallel to the coast of Tholen for OESTER DAM some time before linking up with it. This was to prevent shipping WESTERN in the Scheldt-Rhine link from being subjected to unnecessarily MARQUISATE QUAY strong transverse currents during work on the closing of the Tholen Gap. The road along the dam links up with a road along EASTERN SCHELDT LAKE MARQUISATE the shore which follows a watershed in the Schakerloo polder, so no inroads had to be made in the natural landscape in the DISCHARGE CANAL KREEKRAK LOCKS course of construction work. The southern section of the dam forms the western bank of the discharge canal which enters the Western Scheldt at Bath. The longitudinal geological profile of the bed of the Eastern SOUTH BEVELAND Scheldt where the dam is situated shows clearly the erratic nature of the composition of the estuary bed at the site. The The Scheldt-Rhine link between the Oester dam and the Marquisate section bordering the Scheldt-Rhine link was SO poor that the Quay weaker layers had to be reinforced with sand. In places where there was already an upper layer of sand several metres thick, this expensive process of reinforcement could be eliminated by building the dam in stages. This meant that large sections of the dam had to be filled in gradually with gently sloping layers until the subsoil had adjusted sufficiently to enable the dam to be built up to the required level. The top of the dam is 5.6 metres above A.O.D. A single carriageway road runs along the top, with a Right: the construction island for the lock in the Oester dam. In the parallel road for agricultural and service vehicles. background, the Kreekrak locks. Longitudinal geological profile of a section of the Oester dam. LOCK MAROLLE GAP A.O.D. -5.00 -10.00 -15.00 SAND CLAY -20.00 PEAT SAND WITH CLAY CLAY WITH PEAT 20 21 The Marquisate Quay In order to prevent excessive current velocities near the Tholen bank and the formation of strong transverse currents which would hinder shipping in the Scheldt-Rine link during the construction of the Oester dam, the area of water to the east of the Oester dam had to be reduced in size. To this end the inundated land in the Marquisate area near Bergen op Zoom was enclosed with a quay wall. This produced an area of approximately 2000 ha. where the marine environment could gradually adapt to the new situation. It has also made possible urban extension in Bergen op Zoom and the creation of additional recreational facilities in the area. Partly for the purpose of the former, a neck of land with an area of about 160 ha. was created in Lake Marquisate using sand produced by the excavation of the Bath discharge canal. This means that the Scheldt-Rhine link follows a course between the Oester dam and the Marquisate Quay. The western section of the Marquisate Quay and the Kreekrak lock complex. / 22 Closing the Channels The compartmentalisation dams intersect four different channels. All four of them - the Marolle and Tholen Gaps in the Oester dam and the Slaak and Krammer channels in the Philips Dam - were then closed off in turn using dredged sand. In the case of the secondary channels (the Marolle Gap and the Slaak) the gaps were gradually reduced in size as a sand dam was constructed in a southerly direction. More sand was lost as the channel velocities increased, but since the main channels were still open, the sand loss was restricted and it was possible to close the gaps. In the case of the main channels, the drop over the gap was SO great that a sand dam was not feasible. However, it was possible to use the storm surge barrier to influence tidal flow in the Eastern Scheldt in such a way that current velocities in the closure gap, and therefore also sand loss, were kept within limits. In closing the Krammer channel the principle of 'retarding' and 'reducing' tides was applied: the tidal cycle was retarded from twice a day to once a day. The tidal range was gradually reduced in the final stage of the project, and the storm surge barrier had to be closed completely for the last 1-2 days. A stone wall had been considered as a means of closing the Tholen Gap, but this method proved to be much more expensive, and it had few advantages over a sand dam. Suction dredgers obtaining sand from sites near a closure gap STORM SURGE BARRIER PARTLY OPEN CLOSED OPEN PARTLY OPEN AVERAGE WATER LEVEL IN METRES, +1.00 A.O.D. IN RELATION TO A.O.D: 16 20 24 4 8 12 16 20 24 HOURS -1.00 NORMAL TIDES TIDES WITH REDUCED FREQUENCY The average vertical tidal range during closure of the channels. Pumping up sand for the sand wall 23 The construction island for the Philips dam with the Slaak (right) and the Krammer (left) closure gaps. The Molenplaat sandbank with (top right) the construction island for the Tholen Gap lock and closure gap 24 Closing the Marquisate Quay The Marquisate Quay was closed in the spring of 1983. The gap, with a breadth of 800 metres and an average depth of two metres below A.O.D., was closed vertically by construction of a containing wall in consecutive layers. This was done principally at low tide by lorries and tipper trucks. The winter closure gap and the final section of the first layer of stone were placed by special stone-dumping vessels. When the wall had reached the required height a sand wall was added behind it in such a way that a large proportion of the stone could then be removed and used elswhere for another part of the project. RUK Tipper trucks dumping stones at low water. The quay wall and cranes at low tide 25 The Bath discharge canal THE BATH DISCHARGE CANAL A great deal of the water in the surrounding countryside drains EASTERN SCHELDT into the peripheral lake behind the compartmentalisation dams which stretches from the Volkerak dam in the north to the Kreekrak locks in the south. The lake is thus a reservoir for excess water in the area. In order to permit control of water levels and water quality it is desirable to have facilities for allowing OESTER DAM KREEKRAK LOCKS water to enter the lake and for removing excess water. Fresh river-water can enter the peripheral lake via the Volkerak inlet sluices, but for evironmental reasons fresh water cannot be discharged into the Eastern Scheldt. Nor can water be discharged into the southern section of the Scheldt-Rhine link because the water level in this canal is 1.8 metres higher than that in the lake. This would only be possible if pumps were used and owing to high energy costs this option was dismissed. This accounts for the decision to discharge excess water into the Western Scheldt via the Bath canal. The water in the Western BATH DISCHARGE CANAL Scheldt is also salt but environmental requirements are less SCHELDT-RHINE LINK stringent there than in the Eastern Scheldt, since the quality of the water is also influenced by the fresh water in the river Scheldt and the large-scale discharge of water from polders and waste waters. Water from the peripheral lake is carried to the Western Scheldt via an 8-kilometre discharge canal which runs across BATH the neck of South Beveland. At low tide the water in the Western Scheldt is lower than in the lake SO that pumps are not required. A discharge sluice was built at the southern end of the canal near DISCHARGE SLUICE Bath on the Western Scheldt SO that the water can flow into the Western Scheldt. At high tide the sliding gates are lowered to WESTERN SCHELDT prevent salt water flowing into the canal and to prevent flooding of the agricultural land in the vicinity. As an additional safety Route followed by the Bath discharge canal measure there is an emergency gate which closes automatically under the pressure of the water at high tide. On its way south the canal crosses the following before entering the Western Scheldt via the discharge sluice: - a pipeline viaduct - National highway 258 - the Flushing-Roosendaal railway line - National highway A58 - two series of pipelines - the Bath road - a drainage canal. The intersections with the pipeline viaduct and the national highways can take the form of fixed bridges since no shipping passes through the canal. The other pipelines run in culverts under the canal and in order to drain the land east of the Scheldt- Rhine link continuously a siphon was constructed under the canal with two tunnels with a cross-section of 2.7 X 2.00 metres and a floor depth of 11 metres below A.O.D. Part of the 8 million cubic metres of soil produced in digging the canal was used for the construction of the southern section of the Oester dam and for the neck of land which was created in Lake Marquisate. 26 SUN VOLKERAK FRESHWATER HIGH TIDE RAIN EVAPORATION DISCHARGE POINT FRESH WATER KRAMMER LOCKS FOR AGRICULTURE TIDE 1 WATER LEVEL IN PERIPHERAL SALTWATER LAKE, APPROX. A.O.D. FRESH WATER POLDER DISCHARGE BERGSCHEDIEP SALT WATER FRESHWATER SLUICE FRESH WATER SALTWATER PERIPHERAL LAKE SLUICES OPEN DISCHARGE SLUICES CLOSE SLUICE LOW TIDE DISCHARGE CANAL FRESH RIVERS IN BRABANT GRAVITY DISCHARGE KREEKRAK LOCKS WESTERN SCHELDT Diagram of the water balance in the area The discharge phase in the Bath discharge canal View of the bridges over the projected discharge canal. From left to right: National Highway A58 (dual carriageway), railway bridge, National Highway 258 and the pipeline viaduct. The route of the discharge canal runs parallel to the Scheldt-Rhine link. A drainage canal carrying water from West Brabant crosses the discharge canal by means of a siphon. The Bath discharge sluice discharged - 5 to 6 metres per second - necessitated the construction of a wide outlet to the sluice in order to reduce the The discharge sluice near Bath has an average capacity of over velocity at the point of discharge. For this reason the concrete 24 hours of 100 cubic metres per second through a total of six floor of the outlet area was built one metre lower than the floor of tunnels. Consideration was also given to a siphon pump system the tunnels, i.e. 6 metres below A.O.D. and the walls of the outlet but the present system of tunnels and a free-fall drop proved the section gradually widen over a distance of 20 metres from the most satisfactory solution. Discharge through the tunnels is mouths of the tunnels. At the outer end of the outlet section a 2.5 regulated by a system of lifting gates. When the flow of water is metre high serrated wall was constructed to distribute the slight, one or more of the tunnels are sufficient for discharge current as it flows out onto the concrete-reinforced bed of the purposes. Western Scheldt. The sluice was built in a construction dock The principle used for the sluice, which acts as a spillway, causes which had been pumped dry and rests on a foundation of 570 high current velocities and without preventive measures the floor concrete piles. would be washed away. For this reason a protective layer of concrete blocks and stone was employed. For hydraulic engineering and economic reasons a sill depth of 5 metres below A.O.D. was chosen; the top of the tunnels is at 0.25 metres above A.O.D. The high velocity of the water being +10.00 + 4.00 BATH DISCHARGE WESTERN CANAL SCHELDT LIFTING GATE - 3.50 GATE A.O.D. - 5.00 DIRECTION OF CURRENT 6.00 23.00 30.50 10.00 8.50 10.00 14.50 Cross-section of the Bath discharge sluice The outlet into the Western Scheldt showing the serrated distribution wall. 29 The Lake Grevelingen siphon sluice If ever it should be decided to make Lake Grevelingen a freshwater lake, the Flakkee sluice could be used to direct water One piece of construction work not directly connected with the in the opposite direction. In this case the sluice will have to be compartmentalisation works is the sluice in the Grevelingen extended through the Philips dam to the planned freshwater dam. This sluice, known as the Flakkee sluice, is designed to peripheral lake behind it. From there fresh water can be directed control the quality of the salt water in Lake Grevelingen and the to lake Grevelingen and discharged into the North Sea through Eastern Scheldt by siphoning off the water in Lake Grevelingen. the sluice in the Brouwers dam. The salt water would thus be In the seventies a discharge sluice was built in the Brouwers forced out of Lake Grevelingen. The Flakkee and Brouwers dam dam, which forms the western boundary of Lake Grevelingen, to sluices would thus discharge water in the opposite direction to enable salt water from the North Sea to be added to the that which would apply if Lake Grevelingen were to remain a stagnant salt water in the Lake. It can also be used to discharge saltwater lake. However, it was decided in 1986 that it should water from the lake into the North Sea. This is necessary in order remain a saltwater lake, at least for the time being. to maintain the salt content of the water in Lake Grevelingen which is 'contaminated' by, among other things, the discharge of fresh water from the polders. The new siphon sluice in the Grevelingen dam makes it possible to discharge water into the Krammer which flows directly into the Eastern Scheldt. In this way Lake Grevelingen can be 'flushed' with seawater which enters by way of the Brouwers dam and passes into the Eastern Scheldt by way of the siphon in the Grevelingen dam. In the final stages of the Delta project this arrangement ensured that the salt content of the water in the northern section of the Eastern Scheldt and the Krabbenkreek was maintained. This was necessary because, in the period before the compartmentalisation dams were completed, precipitation, fresh water from the Volkerak and water draining from the polders would have caused the salt content there to fall. In order to prevent damage to the marine environment during this period the Flakkee discharge sluice had to direct water of sufficient salinity to the Eastern Scheldt. Ways of flushing Lake Grevelingen Continuous line = movement of salt water Dotted line = movement of fresh water BROUWERS DAM SLUICE HARINGVLIET LAKE GREVELINGEN GREVELINGEN DAM NORTH SEA SIPHON SLUICE EASTERN SCHELDT KRABBENKREEK WESTERN SCHELDT 30 The siphon sluice in the Grevelingen dam The Brouwers dam sluice The construction of the siphon LAKE GREVELINGEN KRAMMER The siphon consists of arched tunnels in the Grevelingen dam VALVE OPEN which form a link between Lake Grevelingen and the Eastern Scheldt. The upper section of the tunnels is an inverted U-bend, the underside of which is situated above mean highwater level. This means that the water cannot normally flow through the tunnels. In order to activate the siphon, air is extracted from the upper section by means of a vacuum pump. The water then rises STAGE 1, SIPHON NOT IN OPERATION, AT ATMOSPHERIC to fill the ensuing vacuum and flows through the arch in a PRESSURE continuous stream from one side to the other. The principle is the same as that used to empty a fish tank by means of a hose over the edge once the air has been siphoned out of the hose. The flow is stopped by allowing air to re-enter the arched section. The siphon complex consists of two groups of three adjacent VACUUM PUMP VALVE CLOSED arched tunnels, each tunnel being 3.2 X 3.2 metres with a combined effective cross-section of 50 m2, the average capacity over a 24-hour period is equivalent to 80 m³ per second. Although the principle of the siphon is simple enough, additional hydraulic engineering research was required because of the dimensions of the project, particularly with regard to the STAGE 2, CREATION OF A VACUUM CAUSES ATMOSPHERIC operation of the siphon and the design of the outlet and PRESSURE TO DROP reinforcement of the subsoil. In periods when the water level in the Krammer is higher than 3 metres above A.O.D. the siphon begins to draw water automatically in the direction of Lake Grevelingen. This is counteracted by using a compressor to keep the air in the VALVE CLOSED arched section under overpressure. STAGE 3, SIPHON COMES INTO OPERATION AND WATER BEGINS TO FLOW THROUGH TUNNEL The principle of the Grevelingen dam siphon sluice The arched section of the siphon under construction. 32 Published by the Information Department of the Ministry of Transport and Public Works Photographs: Aerocamera Bart Hofmeester, René Kleingeld, Jaap Wolterbeek, Rijkswaterstaat Layout: Driek Drost, Voorburg Printed by the Dutch Government Printing Office 1987. 2nd Impression