Haringvliet

Near Numansdorp, the Hollands Diep splits into the Haringvliet and the Volkerak estuaries. It is closed off near Goedereede from the North Sea by the Haringvliet sluices, which provide a road connection between the island of Voorne to the north and the island of Goeree-Overflakkee to the south. The sluices were built as part of the Delta Works sea barrier protection works, and allow for a brackish ecological environment.

The Haringvliet estuary contains the island of Tiengemeten, which is separated from the river island of Hoeksche Waard by the Vuile Gat strait.