Twenty-Five Years of Groundwater Depletion and Recharge across North America

Abstract. Groundwater and lakes supply water for human activities, support ecosystems, and influence local and continental climate. Despite this, monthly to interannual-scale impacts of changing climate on continental-scale groundwater and lake water storage are poorly understood. We bridge this gap by simulating the North American climate-driven changing water table at monthly frequency from 2000 to 2025. We find an overall decline in storage, with depletion rates in some areas reaching 10 cm/yr while other areas undergo slow but steady recharge. Over 57.6 % of land area experienced an overall decline in water table depth, and total continent-wide storage decreased by 566.20 km³ or 1.57 mm sea-level equivalent. Most depletion occurred between 2005 and 2015, driven by widespread droughts and increased evapotranspiration, which was followed by partial recovery after 2015. Water table changes occurred predominantly in groundwater storage, while lake storage remained relatively steady, and declining water tables preferentially affected human population centers, with 63.25 % of the continent showing groundwater responses consistent with land-cover vulnerability patterns. Our results show that climate forcing alone can drive substantial continental-scale groundwater loss and emphasize the growing vulnerability of the North American groundwater system, establish a baseline for assessing future climatic impacts on continental water resource availability, and highlight the urgent need for adaptive water management under intensifying climatic stress.