California's drought permanently compacted Sacramento Valley aquifer, study finds

Scientists found groundwater pumping during California's 2020–2022 drought permanently compacted part of the Sacramento Valley aquifer, reducing its capacity to store water and threatening future agricultural water security. Published in PNAS, the study used satellite data showing parts of the Sacramento Valley sank over half a meter. Normally aquifers rebound after rain, but pore spaces collapsed so severely during 2021 extraction that storage loss is irreversible on human timescales. The Central Valley grows roughly a quarter of U.S. food, and aquifers previously considered resilient may suffer similar damage worldwide, warning drought-prone regions relying heavily on groundwater to manage extraction sustainably.