Construction of the Grevelingen dam started in 1958. After seven years of hard work, the dam was finished. With a length of six kilometres, the Grevelingen dam was much longer than both the Zandkreek dam and the Veerse Gat dam. Caissons were not suitable for this project, so a revolutionary technique was used to build one part of the dam. Cable ways were used to plunge large blocks of stone into the water. The rest of the dam was built by means of usual techniques, such as raising the sand and sinking down the caissons.
Besides the revolutionary construction technique, the dam is special for one more reason. That is, it was not primarily built to protect against floods. Many would argue isn’t that the prime purpose of all dams? That is true, but not necessarily for sea water. The Haringvliet dam was situated to the west side of the Grevelingen dam. The construction of this dam was started earlier (1956), but the works would last until 1972. The Grevelingen dam had to facilitate the construction of the Haringvliet dam, the Brouwers dam, and the Oosterschelde barrier. As Brouwers dam would have been constructed first, the water from the Grevelingen lake could have flowed back towards the sea via the Haringvliet (in the north) or the Oosterschelde (in the south). This extra current was not desirable.