Tool risk reduction measures


Dry detention reservoirs and depressions of any capacity

Natural or artificially created detention basins and depressions with a specific retention capacity can be used as temporary water reservoir for runoff water during heavy rainfall. They slow down the surface runoff; thus they contribute to a delay and attenuation of flood waves. They should be located at the deepest point in almost any surrounding – farmland, forests, along watercourses or within settlement areas on public or private ground. They fall dry during dry periods. Surface drainage water needs to be diverted towards them; regular maintenance needs to be assured (material accumulation).

Fields of action
Settlement areas, Watercourses, Farmland, Buildings, Forests
Additionally to flood risk reduction by slowing and storing surface runoff, the measure has medium or high possible benefits for the following biophysical impacts and ecosystem services: Water storage; Biodiversity preservation; Climate change adaptation and mitigation; Filtration of pollutants; Recreational opportunities; Aesthetic/cultural value; Increase evapotranspiration; Intercept pollution pathways; Reduce erosion and/or sediment delivery; Create terrestrial habitats



Sabine Scharfe, Saxon State Office for Environment, Agriculture and Geology