Meuse (river) - Distributaries

Distributaries

The mean annual discharge rate of the Meuse has been relatively stable over the last few thousand years. One recent study estimates that average flow has increased about 10% since 2000 BC. The hydrological distribution of the Meuse changed during the later Middle Ages, when a major flood forced it to shift its main course northwards towards the Merwede river. From then on, several stretches of the original Merwede were named "Maas" (i.e. Meuse) instead and served as the primary outflow of that river. Those branches are currently known as the Nieuwe Maas and Oude Maas.

However, during another series of severe floods the Meuse found an additional path towards the sea, resulting in the creation of the Biesbosch wetlands and Hollands Diep estuaries. Thereafter, the Meuse split near Heusden into two main distributaries, one flowing north to join the Merwede, and one flowing directly to the sea. The branch of the Meuse leading directly to the sea eventually silted up, (and now forms the Oude Maasje stream), but in 1904 the canalised Bergse Maas was dug to take over the functions of the silted-up branch. At the same time, the branch leading to the Merwede was dammed at Heusden, (and has since been known as the Afgedamde Maas) so that little water from the Meuse entered the old Maas courses, or the Rhine distributaries. The resulting separation of the rivers Rhine and Meuse is considered to be the greatest achievement in Dutch hydraulic engineering before the completion of the Zuiderzee Works and Delta Works. In 1970 the Haringvlietdam has been finished. Since then the reunited Rhine and Meuse waters reach the North Sea either at this site or, during times of lower discharges of the Rhine, at Hoek van Holland.

One recent study notes that the difference between summer and winter flow volumes has increased significantly in the last 100–200 years. These workers point out that the frequency of serious floods (i.e. flows > 1000% of normal) has increased markedly. They predict that winter flooding of the Meuse may become a recurring problem in the coming decades.