Managed aquifer recharge to ensure sustainable groundwater abstraction under extreme drought conditions

Public water suppliers face challenges due to climate change that are increasingly difficult to predict. Although climate models predict slightly increasing or at least constant groundwater recharge rates across most regions of Germany in the long-term future (until 2100), extreme weather events can cause both significant natural and technical supply fluctuations. These, together with peak demand in times of drought, can lead to serious water supply shortages.

In this project, water supply companies and research institutions cooperate to develop adaptation strategies and management models for future drinking water supplies. One goal is to develop and evaluate new operating concepts and possible adaptation strategies for water production from bank filtrate. Using detailed groundwater models, the effects of flood and low flow scenarios on bank filtration are examined.

In a second step, a concept for sustainable groundwater enrichment for bank filtration was developed based on the spatial and resource use analysis. Simulations of groundwater flow were used to evaluate how managed aquifer recharge (MAR) can help to simultaneously ensure sustainable groundwater withdrawals for public water supply as well as agriculture, while at the same achieving nature conservation and flood protection. We conclude, MAR can be used to reduce potential conflicts between different human water demands and ecological conservation by stabilizing land-based groundwater levels.