Brielse Maas

[1] The damming of the Brielse Maas was part of an extensive plan to make the islands of Rozenburg, Voorne-Putten and Welplaat into one water management unit.

The works also consisted of a dam in the Botlek, a canal through the Hartel area and a system of fencing, drainage and inlet locks.

The work began over the 900 metres (3,000 ft) wide salt marsh on the south side of the island of Rozenburg.

[2] The dam through the Botlek at the east end of the river was also closed in June 1950 with the help of small caissons.

The lake is connected to the Oude Maas via locks at Spijkenisse via the Shipping and Feeding Canal (Dutch: Scheepvaart- en Voedingskanaal).