Regarding the rehabilitation of the elevated tank Dörnberg II, IWR GmbH has successfully completed all service phases according to HOAI. Elevated tank Dörnberg II is operated by Wasserbeschaffungsverband (WBV) Dörnberg, the provider of the municipal water supply.

WBV Dörnberg handles the supply of both potable water and water for firefighting for the municipalities of Ahnatal and Habichtswald in North Hesse. About 13,000 inhabitants are connected to the public water supply in these areas, in addition to agricultural enterprises and other businesses as well as public institutions such as schools, nursery schools and sports grounds. Most of the drinking water reservoirs of WBV were built in the 1970s. All pipes still consist of cast iron (SGCI). WBV Dörnberg has decided that all pipes within the drinking water reservoirs shall be gradually replaced with stainless steel pipes. Besides the replacement of the piping at elevated tank Dörnberg II, minor demolition works, and the installation of new lighting as well as a new entry into the water chamber have been completed.