Quantifying the effect of managed aquifer recharge on the hydrologic resilience of coupled surface-groundwater systems in northeast Germany

Abstract

Study region: A mixed forested/ agricultural area within Brandenburg’s lower Spree catchment, northeast Germany. Study focus: This study examines the potential of managed aquifer recharge (MAR) to stabilize groundwater and connected surface water resources affected by climatic and anthropogenic impacts by reducing declines and overall variability. Utilizing an integrated surface water-groundwater model, the suitability of selected topographic basins was assessed in terms of their ability to recharge the underlying aquifer with surplus discharge water from local streams. After analyzing the aquifer’s response to increased groundwater recharge, the feedback of connected surface waters to the rise in groundwater levels was quantified and discussed in the context of regional adaptation strategies. New hydrological insight: (1) It was determined that MAR operates efficiently with temporal surplus stream-discharge volumes to induce a significant increase in groundwater recharge and a resulting rise in the groundwater table of up to 2 m.(2) Selected topographic natural small basins were verified as efficient locations to recharge an unconfined aquifer via percolation and may be applied in greater number to strengthen the regional aquifer system.(3) The increase in groundwater levels over longer distances (> 900 m) enables the stabilization of the base flow of connected surface waters and strengthens water related ecosystems via an increase in flow volume by up to 15%.