The low part of the 'Nether'lands
The Netherlands lies in the delta of the large rivers the Rhine and the Maas and is bordered on two sides by the sea. Water everywhere. Large parts of the North and West Netherlands would be permanently or regularly under water if the coast was not protected by dikes or dunes. The lowest part of the Netherlands near Nieuwerkerk a/d IJssel is situated a good 6,26 metres below NAP (Normal Amsterdam Level), the average flood level of the IJ in Amsterdam in 1683/-84. This low situation has, among other things, resulted from the settling of the ground during the centuries after the ground had been brought into cultivation and through the digging off of turf as means of fuel. Now that the sea level is rising at an increasing pace, it has become more important for the coastal defence to be high and strong enough.
The closing off of tidal inlets
Thanks to the Delta works it has become much simpler to defend the coast. Most of the tidal inlets between the islands of South Holland and Zeeland have been dammed off, shortening the coastal line considerably and accordingly reducing the danger of flooding. Only the Westerschelde stayed open in order to maintain a good connection between the Antwerp harbour and the sea. The Nieuwe Waterweg too, the connection to the international port of Rotterdam, remained open, but in times of distress this canal can be closed with the Maeslantkering. It was opened as final part of the Delta works in 1999.
The Oosterschelde dam between North-Beveland and Schouwen-Duiveland is, just like the Maeslantkering, a storm surge barrier, meant to be used in the event of an emergency. This barrier is the largest project in the whole of the Delta works and was completed in 1986. For the benefit of the unique environment in the Oosterschelde (salt marshes and mud flats, underwater life), for which tidal movement is indispensable, the dam has been made pervious to water. That's why it was 2,7 billion EUR more expensive than the initially planned closed dam. Water now flows past the pillars at three places in the barrier. Sliding doors hang over the openings, to be let down in case of danger. In order to make the construction possible, several technological tours de force had to be made possible, unfortunately mostly only for this one project.
On the former artificial island Neeltje Jans, which was laid out on a sandbar in order to build a dam, you will find the amusement park Waterland Neeltje Jans, where you can find out everything about the Delta works and 2,000 years of hydraulic engineering. Trips to the inner part of the storm flood barrier can also be taken.