The project assessed the effects of drought and dryness in Germany on water availability, soil water balance and groundwater and should provide possible solutions and recommendations for actions. Special attention is to be paid to competing uses for water and to less widespread adaptation measures, such as the reuse of treated and further processed wastewater in urban areas.
Of central interest is the extent to which several consecutive years with large-scale, regionally low precipitation, as in 2018 and 2019, influence water availability, the soil water balance and groundwater in Germany. Here, data gaps need to be closed and new representations need to be developed.
Phases of drought and dryness are characterised by a series of conflicts of use, which have already occurred in a regionally differentiated manner or may occur in the future. In order to deal with conflicts of use, there is a need for a tried and tested set of instruments and, above all, supporting information for decision-making in order to reduce and resolve conflicts accordingly. For regions with low groundwater recharge and water availability, possible impacts on public water supply need to be assessed.
Furthermore, possible competing uses are to be analysed, described and evaluated. Such use conflicts are likely to arise, for example, from increasing agricultural irrigation.
A catalogue of measures and supporting rules for decision-making are to be developed in order to avoid, reduce and solve water use conflicts. This should create opportunities to proactively avoid conflicts of use.
Individual options for action are to be examined in detail and, if necessary, tested in case studies. This includes analyses of water retention in the area and, in particular, the development of guard rails for the partial substitution of groundwater and drinking water in irrigation in urban areas by wastewater that has previously been treated in wastewater treatment plants and then further processed.