Germany – Dam-design services – Planungsleistungen Hochwasserschutz Wasserwerk Essen-Überruhr

The Wassergewinnung Essen GmbH (WGE) plans the sustainable modernisation of flood protection in the area of the water treatment plants in Essen-Überruhr along the Ruhr. The existing dyke from the 1960s shows significant weaknesses in terms of stability and tightness due to age- and material-related deficiencies as well as unfavourable subsoil conditions. Repeatedly, during high water events - most recently in July 2021 - seepage and contaminated water outflows as well as waterlogging occurred, which impaired the protective function of the dyke system. Additionally, essential geometric and structural parameters (e.g. crown width, slope inclinations) do not comply with current standards (DIN 19712). Against this background, the implementation of a comprehensive renovation concept is planned. The central element is the relocation of the existing flood protection line and the construction of a new approximately 1.2 km long dyke within the plant premises. The new dyke will be constructed as a three-zone dyke according to the requirements for Class I dykes and will be designed for the design flood HQ1000 plus freeboard. Additionally, drivable dyke crowns, dyke defence paths and necessary structures and connections are planned. In parallel, the existing dyke will be opened by creating five overtoppable breaches. This will reintegrate a retention area, previously separated, into the natural flood dynamics of the Ruhr floodplain. The aim is to improve flood protection through additional retention areas and to ecologically upgrade the floodplain landscape over an area of more than 45 ha. The planning area covers a length of approximately 1.78 km in the area of Essen-Überruhr-Hinsel and includes complex boundary conditions, including existing water management facilities, pipeline infrastructure, protected areas and nature conservation concerns (especially habitats of the common spadefoot toad). As part of the measure, demolition, relocation and adaptation work on existing pipelines, traffic areas and technical facilities will also be necessary. The planning is carried out taking into account water law approval requirements (planning approval procedure according to § 68 WHG) as well as ecological and technical framework conditions. An environmental impact assessment is not required at this time. The aim of the project is to ensure sustainable flood protection for the plant premises and the surrounding areas, to adapt the facility to the state of the art and to create additional retention areas to relieve the Ruhr.