Industrial zone

The Oostvaarderplassen’s history starts as recently as 1968, when large bodies of water were left behind in the newly reclaimed Flevopolder. Obviously something was wrong as the area had been intended for industry. However, there was no immediate need for the latter and the area was left alone. At the time, no one could have predicted that the area would become such an important nature reserve.

Greylag geese

Nature started developing on the fertile clay soil. Marsh fleawort and bulrushes flowered. All manner of birds also immediately took to the area. Greylag geese in particular managed to find the area which provided them with a quiet spot in which to moult. Simultaneously, they grazed the reeds, preventing the area from becoming overgrown. This created an area of great variety which, in turn, provided room for other plants and animals. This set the natural dynamic in motion.

Wetlands

Very rare birds such as Eurasian bittern and bearded reedlings also nested in the area. It gained international recognition as a valuable wetland. In order to ensure that the area did not desiccate after all, a key was built around the wet area in around 1975. This created the current separation between the wet and the dry parts of the area. The dry area kept on setting and ended up being lower than the marsh. The Oostvaardersplassen’s current boundaries were defined in 1982 when it was decided to route the Almere - Lelystad railway line around the area.

Size and peace & quiet

In 1986, the Oostvaardersplassen were made a Staatsnatuurmonument [State Natural Monument]. On this occasion it was emphasised that it was important to retain the size and peace & quiet of the area. This offers Staatsbosbeheer the opportunity to allow a comprehensive, nutrient-rich marsh ecosystem to develop, like those which once characterised the deltas of Europe’s major rivers.

Water level

For the first twenty years, water levels were kept the same year round in order to prevent land developing and to create a good habitat for various important groups of birds. But what was good for one, was detrimental to the other. It proved impossible to keep every species happy. Natural processes with changing water levels caused by precipitation and evaporation proved essential for the development of a species-rich landscape at the Oostvaardersplassen.
Water levels are therefore no longer corrected. Precipitation and evaporation provide drier and wetter conditions. Excess water runs out of the area over a threshold, as it does in many natural marshlands, through the Wilgenbos into the Lage Vaart on the western side of the area. Active management is only required if natural processes are hampered by unnatural causes from outside or the area’s own limitations.

Management

The Rijksdienst voor de IJsselmeerpolders [the State Service for the IJsselmeer reclaimed land] used to manage the area. In 1996, its management was transferred to Staatsbosbeheer.