[5] On 1 January 2019 Binnenmaas was merged with Cromstrijen, Korendijk, Oud-Beijerland, and Strijen to form the municipality of Hoeksche Waard.

[6] Maasdam was founded in the 13th Century in an area which at the time was part of the County of Holland, a state within the Holy Roman Empire.

However, archaeological findings have indicated that the area hosted significant human habitations as early as the start of the Roman Flavian dynasty.

Excavations in several locations have suggested that there was a large Roman settlement in the Maasdam area (on the northern shore of the river) probably from around 70 AD.

The establishment of the Maasdam took place during the reign of Floris V. It was part of the establishment of the Grote Hollandse Waard which in itself was part of the long term policy of land reclamation by the Counts of Holland (since the reign of William I) who saw it as a way to strengthen their political and territorial powers in the region.