More than two billion people and 40% of global agricultural production depend upon unsustainable groundwater extraction. Managed Aquifer Recharge (MAR), the practice of strategically recharging water to replenish subsurface storage, is an important practice for managing groundwater more sustainably. However, it is not yet reaching its full potential to counterbalance growing global groundwater demand. Agricultural Managed Aquifer Recharge (Ag-MAR) is an emerging method for spreading large volume flows on agricultural lands and has the capacity for widespread global implementation. Yet, knowledge gaps, synergies, and trade-offs in Ag-MAR research still exist. In this WRRC Water Webinar, Professor Helen Dahlke describes the practice and feasibility of using agricultural land as intentional spreading basins for groundwater recharge, the opportunities to address climate change with Ag-MAR, and the benefits of Ag-MAR including groundwater storage, increased environmental flows, and domestic well support. Dahlke will present the current state of research with respect to the environmental impacts of Ag-MAR on water quality (e.g., nitrate), crop health and yield, and the multidisciplinary approach needed for communication and coordination of Ag-MAR programs with stakeholders and the public. In groundwater-dependent agricultural regions, Ag-MAR provides an important approach to achieving groundwater sustainability; however, it provides one of many solutions to achieve groundwater sustainability and cannot offset the need for groundwater conservation.
Helen E. Dahlke, Ph.D., is a professor in Integrated Hydrologic Sciences at the University of California, Davis and leader of the UC ANR Water Strategic Initiative. Dr. Dahlke obtained a PhD degree in Environmental Engineering from Cornell University. Her current research interests include surface water – groundwater interaction, water resources management, vadose zone transport processes, and applications of DNA nanotechnology in hydrology. One of her main research efforts focuses on testing the feasibility of using agricultural fields as recharge sites for groundwater banking.