Delta Works
Constructed between 1954 and 1997, the works consist of dams, sluices, locks, dykes, levees, and storm surge barriers located in the provinces of South Holland and Zeeland.
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.
After the North Sea flood of 1953, a Delta Works Commission was installed to research the causes and develop measures to prevent such disasters in future.
The framework is called the 'Delta norm'; it includes the following principles: The most important "dike ring area" is the South Holland coast region.
The loss of human life in a catastrophic flood here can be very large because there is typically little warning time with North Sea storms.
New data elevating the risk assessment on expected sea level rise due to global warming has identified ten 'weak points.'
In the Nieuwe Waterweg, the heightening and the associated widening of the dikes proved very difficult because of public opposition to the planned destruction of important historic buildings to achieve this.
Extra dams and locks were needed at the east part of the Oosterschelde to create a shipping route between the ports of Rotterdam and Antwerp.
Since operating the barrier has an effect on the environment, fisheries and the water management system, decisions made on opening or closing the gate are carefully considered.
Whenever possible, existing engineering constructions would be replaced by more 'nature friendly' options in an attempt to restore natural estuary and tides, while still protecting against flooding.
[citation needed] The re-considerations of the Delta Project indicated the growing importance of integrate environmental impact assessments in policy-making.
Blocking the estuary mouths did reduce the length of dykes that otherwise would have to be built to protect against floods, but it also led to major changes in the water systems.
[10] The original plan was completed by the Europoortkering which required the construction of the Maeslantkering in the Nieuwe Waterweg between Maassluis and Hook of Holland and the Hartelkering in the Hartel Canal near Spijkenisse.
The needed level of flood protection and the resulting costs are a recurring subject of debate, and involve a complicated decision-making process.
[11] In September 2008, the Delta Commission presided by politician Cees Veerman advised in a report that the Netherlands would need a massive new building program to strengthen the country's water defenses against the anticipated effects of global warming for the next 190 years.
