Grevelingenje lake and former arm of the sea is located in the southwestern part of the Netherlands . It is located between the islands of Goeree-Overflakkee and Schouwen-Duiveland and forms the border between South Holland and Zeeland. Before the closure, this former entrance to the North Sea was called Grevelingen. Grevelingenmeer is mainly used for hiking and water sports. The lake has an area of 110 km², a length of 23 km and a width of 10 km.
As part of the Delta Plan works, Grevelingen was closed off and isolated from the seabed by the construction of the Grevelingendam dams in the east (completed in 1965 and Brouwersdam in the west (completed in 1971 ). The salt level is maintained by the Brouwerssluis , a lock in Brouwersdam , which supplies the lake with seawater. There are several sandbanks in Grevelingenmeer, where the waters of the lake are stagnant with seawater. In the hot season, there is a lack of oxygen and life dies, a phenomenon that is accentuated year after year. The decision to return to low tide was to be made in 2019. It required work for four years and could have been completed in 2022.
Geography of Lake Grevelingen
Grevelingen lies between the islands of Schouwen-Duiveland (province of Zeeland) and Goeree-Overflakkee (province of South Holland). On the west side, towards the North Sea, Grevelingen is enclosed by Brouwersdam, on the east side, towards the Oosterschelde, by Grevelingendam. A lock has been built in Bruinisse for shipping to the Oosterschelde.
Nature
In the interests of nature, the water in Grevelingen should remain salty. For this reason, the Brouwerssluis lock is located in Brouwersdam, which is open in both directions all year round except for 30 days from September to December. As a result, seals and even harbour porpoises (Phocoena phocoena) are occasionally seen in the Grevelingen Sea fishing for herring.
Following the reopening of the Spuisluis lock in the Grevelingen dam, which had been closed since 1987 and was also extended and modified in 2017, a connection between the East Scheldt and Grevelingen is now available, both at high tide and low tide on the East Scheldt. The water exchange is taking place in both directions for the first time since 2017 and should help to improve the water quality of Lake Grevelingen.1 The lake is an important nature reserve.
