Delta Works, Netherlands


The flooding in 1953 made it very clear how vulnerable the land and the people living there were. Therefore a huge effort the Delta Works project was made to create a new and better protection to make sure this would not happen again.

The Delta Works protects a large area of land around the Rhine-Meuse-Scheldt delta from the sea. Delta Works is a very complicated collection of locks, sluices, channels, bridges, slides, dams, dikes, storm surge barriers and gates working together.

The aim of the dams, sluices, and storm surge barriers was to shorten the Dutch coastline, thus reducing the number of dikes that had to be raised. This dam consists of several strings of gates and their massive supporting pylons which, in normal weather, allow tidal sea waters to ebb and flow in the Eastern Schelde estuary, thus benefiting the fish, bird life and the local fisheries. The four great estuaries in the south-western Netherlands should be closed with dams. These closures should be done in a special order because of tidal movements of shipping and fishing, this guarantees for the economy of the country.

The piers and their mechanisms had to be lifted into precise positions in the estuary. But the type of equipment needed for such gargantuan and specialized tasks did not exist anywhere in the world; it had to be invented. The piers support 300- to 500-ton steel gates and their hydraulic machinery, as well as a roadway above and load-bearing beams below.

The Oosterscheldedam is on one of the two artificial islands situated in Zeeland, just an hour and a half driving distance from Amsterdam and half an hour from Dordrecht where the structure is located; it is a recommend for those interested in water management. Three kilometres long, this anti-tempest dam is constituted of 65 pillars between which one can slide 62 iron flood-gates.

The height of one pillar is 38 meter and its weight 18.000 tons. When the sea becomes dangerous, one hour is enough to lower the flood gates. This system affords to keep 75% of the tide amplitude as well as the fishing industry, the breed of mussels and oysters and above all, the unique eco-system of The Biesbosch.

One of the latest improvements of the Delta plan was the storm surge barrier in the New Waterway near Hoek van Holland built in 1997. It consists of two enormous doors mounted on swing arms that can be used to close the estuary if storm and high water requires in order protecting the country.

History

During the night of January 31, 1953, to force 12 north westerly windstorm pounded the coast of Zeeland. The weakened dikes, drenched with water, ultimately gave way, flooding the islands of Goeree-Overflakkee, Tholen and Schouwen-Duiveland. The result was disastrous 1835 fatalities, 100000 evacuees, and 200000 hectares of land under water.

After that a commission was installed which had to come up with a plan to research the causes and seek measures to prevent such disasters in future. They revised some of the old plans; the plans were made to connect the South Holland and Zeeland islands by dams. The combination of these plans and dams was called the Delta Plan. The Dutch government unanimously accepted the Delta Act in 1958, thus laying the foundation for the Delta Works. In 1959, the Delta Law was passed, in order to organise the construction of the dams.
The plan consisted of blocking the estuary-mouths of the Oosterschelde, the Haringvliet and the Grevelingen. This reduced the length of the dikes exposed to the sea by approximately 400 miles (640 km).

The dikes along these waterways were to be heightened and strengthened. The works would be combined with road and waterway infrastructure to stimulate the economy of the province of Zeeland and improve the connection between the port of Rotterdam and Antwerp.

The Delta Works consist of more than dams and dikes alone; locks are also needed for transporting high water to the Rhine. Therefore drainage locks have been built in the Haringvliet. These locks began operating in 1971 and have 17 openings, each 56.5 meters wide. The Brouwers Dam in the Brouwershaven Gat was completed in 1972.

Oosterschelde Flood Barrier was created to prevent the creation of too many freshwater areas in Holland, the flood barrier locks are usually kept open and only close during times of extremely high storm tides. This structure, one of the largest in the world, cost 5.5 billion guilders to build and was opened on October 4, 1986.

This project led to dangerous tides causing dangerous floods have been reduced, now are lovely areas to explore by boat. Some of the uncovered shores have become recreation parks. Many sandbars and shores, however, especially in the Oosterschelde, are part of an important nature reserve. It was the largest project of its kind anywhere in the world and took 30 years to build. It is known as the Delta Project.