Biesbosch
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Air view over the Biesbosch area (8). |
The
Biesbosch or
Biesbos (the latter the new spelling, but rarely used), meaning 'forest of
sedges' is one of the largest
national parks of the
Netherlands and one of the last freshwater
tide areas in Europe. The Biesbosch consists of a large network of rivers and smaller and larger creeks with islands. The vegetation is mostly willow forests, with some grasslands and fields of
reed.
The Biesbosch was created when 300 square
kilometres of
polder lands were submerged in the
St. Elizabeth flood in the year
1421. Before this, the area was called
Grote Hollandse Waard, containing cultivated land and a number of villages. The more than a century old dikes collapsed because of lack of maintenance, due to the difficult economic situation in the area, and the difficulties between the political entities within. Very high river levels combined with a severe storm surge coming in from the sea resulted in the flooding of most of the Grote Hollandse Waard. After the flood, three areas remained: the
Island of Dordrecht to the west, the
Land van Altena (with the
city of
Woudrichem) to the east, and the
brackish swamps of the Biesbosch in between. Most of the area changed into a network of
estuaries. The most important of those where the
Hollands Diep and the Bergse Diep. Both were connected to the
Haringvliet which existed before the disaster as a pure sea-water
inlet of the
North Sea. After the disaster it became brackish and an important estuary of the rivers
Rhine and
Meuse. A persistent misunderstanding is that the Biesbosch arose by this storm flood in one night. It is true that this flood broke dikes of the then Grote Hollandse Waard or Zuid Hollandse Waard, but it needed dozens of years before the whole area was under water and had changed to the Biesbosch with its creeks and reeds.
In the beginning the Bergse Diep was a shallow but extended body of water, with high tides but also a predominance of fresh water. The deposits of the rivers caused the waters to become only submerged at high tides. From that moment on the area was called Bergse Veld and later on the Biesbosch. A network of interconnecting creeks, mudflats and forested areas was created. It served as a sort of inland delta of the large rivers feeding it. A significant result of this was that the former estuary arms of the Rhine and Meuse, further north-west, were devoid of much of the inflow of fresh water. This caused the rivers to fill with deposits, so the important shipping route between Rotterdam and the inland areas was no longer usable.
In the last centuries conditions changed significantly. Most of the Biesbosch was reclaimed and turned into polders. The connection with Rotterdam was restored by blocking the build-up of deposits by artificial means. Most of the Biesbosch creeks were dammed-up to lower the risk of flooding. A shipping canal was created to distribute the flow of the rivers: the
Nieuwe Merwede.
Before
1970 a connection with the sea existed, and the tidal differences were, on average, two meters. Due to the inflow of the
Meuse and
Waal rivers, fresh water continued to dominate. The tidal differences diminished to some 20-80 cm after
1970 when the
Delta Works closed the
Haringvliet and with it the Biesbosch's direct connection with the sea.
In
World War II, the area was used by Dutch residents to hide out from the German occupation forces in the Netherlands. A resistance group was formed that, late in the war, captured
Germans fleeing to the north from what was then the
Allied-held south of the Netherlands. In the winter of
1944, the area was crossed by refugees from the occupied north, while, at the same time, it was being used to smuggle
medicines to the north.
*
www.biesbosch.org Official site of the Biesbosch National Park (in Dutch)
