Deltawerken
Netherlands
51° 39′ N, 3° 43′ E
1953
The Delta Works are a series of water defence works in the southwest of the Netherlands. It is part of a long history and policy of water management in the Netherlands.
Following the start of the Zuiderzee works and the construction of the Afsluitdijk, the damming of the Rhine-Meuse-Scheldt delta was studied. The aim was to change the coastline and to transform this delta, which is very prone to flooding, into several bodies of fresh water. However, the Second World War prevented the development of the works. But in 1953, the devastating North Sea flood claimed nearly 2,000 victims and ravaged the province of Zeeland, where the delta is mainly located. The Rijkswaterstaat (Department of Public Works) took over the studies that have been developed for almost 20 years, mainly by Johan van Veen. It launched a new policy of protection against marine submersion, modernised to block the estuaries of Oosterschelde, the Haringvliet and the Grevelingen, and thus reduce the exposure of the dikes to the sea. However, unlike the Zuiderzee works, the Delta works are not a land reclamation plan, a polderization, but a plan to defend the coasts and floodplains. It allowed the construction of monumental and revolutionary hydraulic engineering works associated with an innovation in the management of marine and coastal flows.
The intervention on the Dutch coast is unprecedented, shortening the total length of the dikes by 700 kilometres and raising the dunes by 5m. The creation of freshwater lakes also made it possible to extend the agricultural areas towards the west. And the surplus water sent to the north of the Netherlands. In general, the management of flows and the balance of water has improved and has allowed the creation of natural reserves. Finally, road traffic is made easier, every part of Zeeland is connected to mainland Holland, and river traffic is better regulated.
A review of the projects
There is almost 20 Delta Works projects. Their function is different, they are dams, dikes, bridges, locks… Each one has had a particular development and technology that we study and list here. Access the related posts below.
The Delta Works, a series of dams and storm surge barriers
The Delta Works, The Oosterscheldekering
For example, artificial islands were built to close off the Oosterschelde estuary. This made it possible to build the most important dam of the Delta Plan, the Oosterscheldekering, which is 9 km long. It is a dam consisting of 62 steel slide gates, limiting marine submersion. These large slide gates can be lowered in case of heavy storms. Since its commissioning in 1986, the dam has been closed almost 30 times. The slide gate system, present on 5km, is a consequence of an environmental decision allowing the safeguard of biodiversity.
The longest structure in the Delta Plan is the Oesterdam, an 11km long dam between Tholen peninsula and Zuid-Beveland in the western part of the Westerschelde. This dam also necessitated the construction of an artificial island in 1980. To the south of this island, the 4 km long Markiezaatskade was built in 1982, while the Oesterdam was inaugurated in 1986. These two works made it possible to isolate the freshwater canal from the Scheldt to the Rhine, from Belgium to the Netherlands.
Bridges were also built to cross the estuary and connect all parts of the province to the Dutch mainland. Notably the Zeeland Bridge, inaugurated in 1965, its 5km length made it the largest bridge in Europe at the time.
The Delta project brings together a complex of more than 15 dams or flood barriers in the south of the Netherlands. Recently the Europoortkering (1997) has been added to the delta plan although it is located further north and aims to protect Rotterdam and South Holland. Officially, the delta project was completed in 2010.
Map of all the project sites
The map shows the different places reviewed. Click on the markers to get an overview of the projects sites and access the related post.