One of our main victories over the sea is the Delta works. This great achievement was started after the major flooding disaster in 1953. After that it was decided to make The Netherlands safe for the sea and this was done by closing all the sea-arms in the province of Zeeland. This work was called 'De Deltawerken' which was done over a period of over 33 years. One disadvantage was that all these sea-arms became fresh water. This was a big problem for the population that relied on fishing and breeding of mussels, mainly in the Oosterschelde. Also the very special ecosystem in these waters was at stake, so they came up with a unique and very daring solution: an open dam.
This resulted in a one-of-a-kind dam, one of the technical wonders of the world that established Dutch engineers as the major water specialists in the world. The in mouth of the Oosterschelde the made two artificial islands and between them three stretches of dams, consisting of pillars and big doors. The dam will be closed when the water level rises higher than 3 meters above the normal level (NAP), which occurs so every 2 years. For the rest it is open. So without ado, I visited this dam and below you can see some pictures.
Below the spare pillar, still left where it was build. The pillar exists of a big concrete box with a pillar on top. The box can be flooded in order to sink it at the right spot. When it is empty, it floats. The top carries the big doors and the road. The pillars were build in a dry basin, surrounded by a stone dam. To be able to tow them out, the basin was flooded, so the pillars started to float and they could be taken to their right spot by a specially designed ship. THis pillar was sunk where it was build.
A view of the middle part of the dam, between the two islands. I am standing on the biggest 'work island' and you are actually looking from the Oosterschelde side. The Northsea is behind the dam.
Another view close by. It is becoming high tide and you can see the enormous current that it creates. The current caused by the tides was the major problem building this dam.
A picture in the dam, close to the doors. I took the picture of the space between two pillars (42 meters wide) and you can see how fast the current of the tide flows through this gap.
I picture on the NorthSea side of the dam. In the back you can see another stretch of the dam, going from the second island to the main land. There are three stretches of this dam, spanning a total of 3 km.
A closeup of one of the big doors. They can be pushed down and pulled up by pneumatic cilinders which you can see on top of the pillar. I took this picture with my 300mm from the Oosterschelde.