Wastewater treatment and flood protection
Above all in the 90s, we made large investments in the expansion of our wastewater treatment plants. The pleasing result is significantly improved water quality. Since 1990, the water quality category III (poor) has disappeared along the entire Lippe route. Already then, the quality categories II (good) and II/III (satisfactory) were consistently achieved. At the end of the 90s, the highest achievable category for a lowland river, class II, was achieved for the entire lower course of the Lippe.
As a result of decreasing pollution, many micro-organisms and sensitive fish species such as sea trout and the European river lamprey have returned. Even salmon has been found occasionally. The water quality of the Lippe and its subsidiary waterways is continuously monitored by automatic control stations.
Large-scale coal mining has been taking place in the Lippe region for decades. Amongst other things, this results in severe subsidence, which also affects the Lippe and its surroundings. In subsidence areas, we have therefore built some high dykes along the river. Flood protection also includes allowing a river to break its banks in a controlled manner - where flooding cannot cause serious damage, in watermeadows, grasslands and pastures. Such natural retention spaces contain flood peaks at many points along the Lippe, and they must be preserved.