The water management company of the BioWaWi project, Stadtwerke Bühl (SWB), is the regional supplier of electricity, natural gas, heat and water for the city of Bühl and the surrounding area in the Upper Rhine Graben. SWB has been supplying drinking water for more than 110 years and currently serves almost 45,000 residents in Bühl and the surrounding area. In this project, SWB is seen as an example for the many other drinking water plants with their water protection areas. In connection with its water management activities, SWB aims to contribute to the conservation of biodiversity as well as of ecosystem services (ES) and to introduce an environmental management system for this purpose. SWB was selected as a case study due to its geographical location between the Black Forest and the Rhine plain with numerous protected areas and was assessed in phase 1 for suitability within the research project. The study area is clearly delineated geographically (Figure).
There are three main water protection areas, which are characterized by a large and specific biodiversity. A large part of the area is designated as a Natura 2000 site and is protected as a nature and landscape reserve. Here, the focus is on the protection of habitat types and species of community importance, e.g. the lowland meadows (LRT 6510) as well as butterflies (pale and dark meadow-blue), dragonflies (Helm's azure damselfly) or the small river mussel. Furthermore, the occurrence of a wild bee species included in the state's species protection program is known, whose foraging habitat is the areas' lean, alternately moist meadows. Phase 2 of the project will develop a methodology for managing the biodiversity and ECOL of the water conservation areas that can be applied to the needs of other water utilities. The specifics arising from the SWB example, such as disposal of concentrate water resulting from centralized decalcification, or diversity of ecosystems (from the Black Forest to the Rhine plain) can be used as a blueprint, depending on the circumstances of the water utilities.