Biesbosch

The Biesbosch (from bies, "rushes", and bosch, "woodland") is an area southwest of Dordrecht formed when the dike on the Maas burst and the St Elizabeth's Day floods on November 19, 1421 engulfed great tracts of land in the southwestern Netherlands and altered the geography of the whole area, inundating over 40,000 hectares/100,000 acres of land. Since the 18th century more than four-fifths of the flooded land has been reclaimed. An area of 6,000 hectares/15,000 acres was left as it was, and now forms the Biesbosch nature reserve and bird sanctuary.

Until the end of the 1960s the Biesbosch was directly connected with the sea and subject to changing tide levels. As a result it developed a flora which tolerated brackish water and was the home of numerous waterfowl. Since the damming of the Haringvliet there is no variation in water level, and both flora and fauna have adapted to the new environment.