Dynamising the Water Levels

Reeds need open mud areas for reproduction, especially in the late summer. If they are not available or if they are under water, germination, and thus a spread of the population by means of seeds, is not possible. Therefore, another measure to encourage the reeds is to seasonally dynamise the water levels of the Bienen Old Rhine. This is possible because there is a lock at the outlet where the Old Rhine flows into the Grietherort Old Rhine. This can be used to hold the water back in the Bienen Old Rhine, or, when it is opened, to let the water flow out to a certain level. Level loggers should also be fitted for fine adjustment of the water levels. In this way, the water level can be adapted to the needs of the reeds. Obviously, this is subject to the hydrological conditions permitting this. Thus, for example, it is not possible to lower the water level during floods. When dynamising the water levels, attention is paid to ensure that no critical situation for fish or other water organisms arises when the water level is lowered. To realise this endeavour, talks and close cooperation with the local dyke watch in Grietherbusch and the Bislich-Landesgrenze dyke association are important.

Moreover, implementing this measure can lead to another positive effect. Thanks to the lowering of the water level, it is possible that mud banks with annual short-lived vegetation will form. This is also a valuable habitat protected in the EU. Furthermore, wading birds also like to use mud banks when searching for food.