Development of a water storage toolbox for surface-induced near-nature managed groundwater recharge

Water stress is increasing in Northeast Germany due to climate change. New approaches for water management are needed to mitigate the impacts on the water resources. Therefore, our study deals with the development of a web-based toolbox to manage subsurface water storage by artificial groundwater recharge with focus on the lower catchment of the river Spree in the federal state of Brandenburg. Our approach is based on a systematic combination of site selection criteria and spatial data on land use, soil, groundwater and potential water sources. The aim is to provide relevant information for the preliminary planning of managed groundwater recharge measures by authorities and water suppliers. This includes a wide range of project scales that can be covered by the tool. However, as necessary volumes for large scale recharge projects are unlikely to be found in concentrated form, small scale projects with low demand of infrastructure and energy, are of main concern. Considering surpluses from runoff and surface waters, also caused by extreme weather events, suitable locations for surface-induced recharge will be identified. Thereby, solutions with low environmental impact, like the use of natural depressions for recharge, are highlighted to the user. This will allow for a stabilization of the local water balance, induced by a large number of low impact measures. Supported by additional modelling-based indications for implementation, efficiency and costs, as well as simplified site selection through a query system, the toolbox will offer an initial knowledge for such planning considerations.