The nature reserve with the designation NSG WE 221 is 75 hectares in size. It has been under nature protection since December 17, 1994. The responsible lower nature conservation authority is the Ammerland district.
The nature reserve is located south of the Aper Tief between the towns of Apen and Augustfehn in the municipality of Apen in the Ammerland district. It is bordered to the east by the district road 120 and to the west by the Norderloher Canal. In the south of the nature reserve is the dike of the Aper Tief, which was moved from the bank of the Tief to a road running south of it in 2005. Before the dike line was moved back, there were grassland and wet meadows here, which were crossed by oxbows of the Aper Tief. The grassland was mainly used for mowing. After the dike line was moved back, the areas between the Aper Tief and the dike are subject to the natural river dynamics and are partially flooded at high tide. This creates a river floodplain landscape with river mudflats, floodplain forests and wet biotopes. The areas also serve as flood protection.
Reed beds, including cattails, water swaths, reed canary grass and sedge marshes, are spreading on the waterlogged areas. The nature reserve is home to laurel willow, prostrate St. John's wort, marsh marigold, greater burnet, water ragwort, water sedge, needle marsh rush, bristly marsh rush and thread rush, among others. The nature reserve is home to numerous bird species, including black-tailed godwit, common snipe and redshank. The nature reserve is also an important habitat for various insects, including ground beetles and dragonflies.
In the south of the nature reserve there are two viewing platforms accessible from the road along the dyke, which can be used for nature observation. Another viewing point is located on a pumping station on the north bank of the Aper Tief near Augustfehn.