Biesbosch National Park: Watershed Water Management

Overview of the Area

The Biesbosch is one of the largest national parks in Holland and one of the last freshwater tidal areas in all of Europe. Ironically, the park is the result of human intervention. The original landscape was wiped out by continual land reclamation over the centuries. Then, in 1953, a disastrous North Sea flood destroyed most of the existing dikes in the area and largely wiped out the existing human settlements around the park as well. The Delta Project was subsequently instituted by the Dutch government to create a more systematic and extensive system of dikes, dams, and revetments. Unique in the history of the Netherlands, the Delta Project created the present layout of Biesbosch National Park. This watershed is made up of a vast network of rivers and creeks complete with islands. The vegetation consists mostly of willow forests, marsh grasslands, and reed fields. The Biesbosch represents an important wetland area for waterfowl and possesses a rich flora and fauna ("Biesbosch.org").

Unfortunately, a great deal of environmental stress has been placed upon the park. The Nieuwe Merwede canal, a manmade waterway, divides the Biesbosch National Park precisely down the middle between the provinces of Zuid-Holland and Noord-Brabant. The park section in Noord-Brabant is known as the Brabantse Biesbosch. The section in Zuid-Holland is divided into the Sliedrechtse Biesbosch and the Dordtse Biesbosch. The park covers an area of 9,000 hectares. This division has permanently changed the environment of the park, producing both positive and negative results (ibid).

Despite the importance of the area as a watershed reserve, it was not protected from modification by the Dutch government. Before 1970, there was a connection to the sea, and the tidal difference between the sea and the park area was approximately two meters. The changes eliminated this differential, and fresh water began to dominate the former marine ecosystem. All tidal differences virtually disappeared after 1970, when the Delta Works closed the Haringvliet and with it the Biesbosch's direct connection to the sea. Only in the northern section of the Biesbosch did some of the original tidal difference remain (20–80 cm on average), while in the southern area there was none. The diminishing of the tidal differential caused a drastic transformation in the Biesbosch: the area was converted into a willow forest, with only small remnants of the original delta streams surviving. The Haringvlietdam also blocked the main migration route for fish. The combined influence of the rivers and the sea has almost completely vanished. This had significant effects on the flora and fauna; certain plants and animals became locally extinct while others took their place. It was a drastic development that forced nature to adapt (ibid).

Fortunately, in certain districts of the Biesbosch, nature is managed with as little human interference as possible, due to pressure from the Dutch environmentalist movement. In the long term, these areas will probably develop into marshy woodlands — the type that once covered the wet peatlands in the western part of the Netherlands. The Biesbosch has always been an important region for the rest, foraging, and breeding of rare bird species. This watery wilderness is of such international importance to wild waterfowl and waders that a large area (the Brabantse Biesbosch) has been officially recognized as a wetland. This natural value has been confirmed internationally by European regional agreements such as the Habitats Directive and the Birds Directive (ibid).

The area has a long history of traditional land use, including agriculture, hunting, and fishing. Remnants of those days remain: old reed lands, reed huts of willow workers and farmworkers, duck decoys, quays, and grass dikes with their characteristic pools. Boundary marker trees of former terrain boundaries can still be seen in various places (ibid).

Effects of Pollution

The Biesbosch is heavily polluted with heavy metals. The floodplains of the European rivers Rhine and Meuse carry pollutants such as cadmium into the Biesbosch, affecting life throughout the floodplain area. Concentrations of heavy metals in earthworms and millipedes were found to be elevated compared to reference areas. Since metal concentrations in earthworms were increased relative to animals in unpolluted soils, this fauna group appears to be most at risk. Given the natural engineering role of earthworms in ecosystems, adverse effects upon the ecological functioning of floodplain soils therefore cannot be excluded (Hobbelen, Koolhaas, and van Gestel 409).

The contamination with heavy metals is only the tip of the iceberg in terms of the disastrous human management of resources in the Netherlands. A review of historical water management attempts reveals further examples.

History of Water Management Attempts

The history of Dutch water management in the region dates back to approximately the 9th century. The period until the 13th century was marked by the loss of large portions of land. Simultaneously, the reclamation of peatlands had begun in the west of the country. This caused a considerable drop in the water table, making lands more available for human exploitation — though these lands below sea level were constantly threatened by floods from the sea ("Integrated river basin and watershed management").

The North Sea Flood Disaster of 1953 was a rude awakening for the country. A powerful north-westerly storm combined with a spring tide resulted in the inundation of large parts of the provinces of Zeeland and South Holland. More than 1,800 people were killed, and the flood caused enormous damage to houses and property. Measures to prevent a repetition of the 1953 disaster were put in place in the form of the Delta Plan: dikes in Zeeland and South Holland had to be raised to delta level (ibid).

The Netherlands built the Delta Works and thereby gained a reputation as a country that had won the war against the water. In 1993 and 1995, however, the Netherlands faced further floods due to climate change, which resulted in increased snowmelt and rainfall from upstream areas. New projects and a new approach to water management were therefore needed. Rather than continuing to raise the height and size of dikes, the concept of making more space for water was explored (ibid). This has led to the development of watershed areas used as natural waterbreaks.

Works Cited

Biswas, Asit K. Water Management in 2020 and Beyond. 1st ed. New York, NY: Springer, 2009. 190.

De Villiers, Marq. Water: The Fate of Our Most Precious Resource. 1st ed. New York, NY: Houghton Mifflin Harcourt, 2001. 3.

Hobbelen, P.H.F., J.E. Koolhaas, and C.A.M. van Gestel. "Risk Assessment of Heavy Metal Pollution for Detritivores in Floodplain Soils in the Biesbosch, the Netherlands, Taking Bioavailability into Account." Environmental Pollution 129 (2004): 409–19. Print.

Hopkins, Anna. "Communities and Waterpoint Management." The Chapter Buzz. blogs.ewb.ca/annahopkin, 21 Oct. 2011. Web. 25 Oct. 2011.

"National Park De Biesbosch." Biesbosch.org. Biesbosch, 2011. Web. 25 Oct. 2011.

"Sustainable Tourism in the Biesbosch Region." Step-projects.eu. Parkschap Nationaal Park De Biesbosch, 11 May 2011. Web. 25 Oct. 2011.

"Integrated River Basin and Watershed Management." Waterland Information Network. Waterland.net, 2011. Web. 25 Oct. 2011.