Groundwater recharge as an adaptive response to flood events in the San Joaquin Valley, California

ABSTRACT Groundwater is a critical resource for both nature and society, yet aquifers are rapidly depleting globally. This includes the southern San Joaquin Valley, California, a productive agricultural region that suffers from drought. However, in spring 2023, the region experienced record-breaking precipitation. Managed aquifer recharge (MAR), groundwater recharge and storage via human-made processes, is a possible adaptive response to extreme events. We utilized a mixed-methods approach that included remote sensing, farmer interviews, and newspaper content analysis to address two research questions: (1) what were the impacts of the spring 2023 flood event?, and (2) how might MAR be utilized to adapt to future extreme events? Remote sensing results found that between November 2022 and March 2023, the amount of water on the landscape increased from 44.4 to 370 km2. During our interviews and newspaper analysis, both negative (evacuations, damage to homes and infrastructure, increased mosquito populations, flooded agricultural fields) and positive impacts (increased water availability, government funding) of the flooding were described. Results revealed benefits of MAR (increased groundwater levels, water availability, decreased subsidence), as well as constraints/concerns (complexity of monitoring, groundwater contamination, lack of infrastructure). Results show the support for MAR projects and policies as an adaptive strategy for floods and droughts.