Floodplains
According to Section 76 of the Federal Water Act (WHG), the federal states are obliged to designate certain floodplains by ordinance. The floodplains established in this way form the basis for the local authorities' urban land-use planning, among other things.
First of all, areas with a potentially significant flood risk are defined as risk areas in accordance with Section 73 (1) WHG.
Within these risk areas, the areas in which a 100-year flood event (HQ100) is to be expected are to be officially designated by the Cologne district government.
A HQ100 is a flood event that statistically occurs at a location once every hundred years.
In particular, natural floodplains should be established or maintained as flood retention areas. This may also make it possible to avoid the construction and maintenance of flood retention basins.
There are legally established floodplains in Aachen for all bodies of water whose catchment area is larger than 10 km². This applies to the Inde, Wurm, Wildbach and Haarbach rivers.
Responsible authorities:
- Cologne district government | Determination of floodplains, creation of flood risk and management maps
- Eifel-Rur Water Association | Construction of flood protection measures up to HQ100 in the Rur catchment area
- Lower water authority | Implementation of flood protection measures up to HQ100 in the Senserbach and Tüljebach catchment areas
- Lower water authority | Approval authority for actions in floodplains / approval of flood protection measures