Keywords:
Atlantic region
Island barrier dunes
Hydrology
Wetland restoration

Contact :  Mr.Freek  Zwart, Staatsbosbeheer (SBB), Longway 28,8881 CM Terschelling, tel: ++31(0)562442116, fax:++31(0)562442208

Location :  NL, Waddensea, NW-Terschelling, Green beach

Rivulet and Green beach
In the western part of the island Terschelling, the green beach is a low-lying area east of the Noordsvaarder, a former sandbank. In 1911 a dike was built to prevent the sea from entering the area, and the northern part was exploited for agriculture. The northern part is now disturbed and acidified but no longer in use for agriculture.

Management
The aim is to preserve and develop the diversity of the landscape, flora and fauna, by using the natural dynamics of the sea and wind and the natural hydrological conditions. This is done by :

• restoring the regular flooding with seawater throughout the area,
• restoring the original hydrological situation and a brook (“Rivulet” or “riviertje”), and by
• restoring the soil conditions.

Nature restoration
The tidal inlet is  widened to restore the tidal movements and the road was lowered. The dike is fully excavated and an artificial sandbar is removed. Groundwater level was raised by filling up the drainage ditch with material from the excavation of the dike. Acidification can be reduced by restoring groundwater level and flooding with seawater. The soil was levelled up to the original height. In lower sections sods were removed to stimulate pioneer vegetation. The area can under normal conditions be visited by a footpath and a metalled road.

Results
The average flooding frequency is 10 to 12 times a year. A larger variety of gradients already appeared. Groundwater level has risen, and the Rivulet is restored. Vegetation is restoring, for example some species of the Dwarf Rush association reappeared, Dwarf Sedge, British Club Rush, and Dwarf Rush.
 
 

 The rivulet on the isle of Terschelling in the Waddensea

References :

• Staatsbosbeheer, Rijkswaterstaat, Beheersplan rijksgronden Terschelling 1992-2002, een samenvatting (in dutch)
• F. Zwart, The green beach (Groene strand) and the Rivulet (Riviertje), restoration and construction, 1997
• internet : www.waddensea.org