Inter-state inland waters flood protection
This lead project is aimed at improving protection of inland waters in the catchment area of the Brookwetterung stream, by taking steps to increase retention of surface water and matter. To implement the project, inter-state cooperation, based on catchment areas, is involving the affected areas of Herzogtum Lauenburg, the town of Geesthacht and the Free and Hanseatic City of Hamburg.
Hamburg Metropolitan Region – Inter-state inland waters flood protection
First of all the entire catchment area of the Brookwetterung stream was investigated for ways of retaining water and sand, then the first measures were put into practice. At Börnsengraben, a flood surface area, 3,300 sq m in volume, and a sand filter/sedimentation basin were installed. On the Bis, three former fish ponds were converted into retention ponds with a storage volume of 5,000 sq m. In 2008, a surface area for the Geesthacht area of 1,000 sq m accumulated volume is planned.
A sand filter is to be installed in the Sander Knollgraben to prevent sand being transported into the Brookwetterung. Further steps will be taken in 2009 at inflow locations to reduce the cargo of sand in the Dalbek river even more. Further sand filters in combination with retention are also being considered for Escheburg.
Flows of water in confluences of the Dalbek with adjacent ditches and of adjacent ditches into the Brookwetterung are to be optimised technically. Another important scheme is the complete hydraulic overhaul of the Brookwetterung to take into consideration the Water Framework Directive.
Overlapping the states involved, very good cooperation has developed between municipalities, towns and the district. This good cooperation is to serve as the basis for a water and soil alliance, initially only to include the Lauenburg area, but which will later expand across state boundaries into the Hamburg area.