The paradox of production: Surface water supply drives agricultural productivity but not prosperity in California’s San Joaquin Valley

Abstract

Societies globally are struggling to meet freshwater demands while agencies attempt to address water access inequities under a rapidly changing climate and growing population. An understanding of dynamic interactions between people and water, known as sociohydrology, regionally could provide approaches to addressing local water mismanagement and water access inequity. In semi-arid California, local water agencies, primarily agricultural irrigation districts, are at the intersection of rethinking approaches to balance freshwater demands. More than 150 years of complex water governance and management have defined San Joaquin Valley irrigation districts and the region’s water access inequities and sociohydrologic instability. Older irrigation districts have higher surface water allocations and less groundwater dependence. About 60% of irrigation districts with pre-1914 water rights have twice the crop water demand in surface water allocations. In contrast, 86% of irrigation districts depend on groundwater, of which 12% rely exclusively on groundwater to supply irrigation demands. This study found that disadvantaged communities within irrigation districts do not have increased water access or better environmental conditions than those outside irrigation district boundaries, which underscores the need for inclusive water management structures to address the multifaceted water and environmental inequities. Groundwater overdependence across irrigation districts shows that imbalanced surface water allocations and inflexible crops could imperil agriculture and impact agricultural disadvantaged communities, especially under California’s SGMA and prolonged drought events. It is imperative that underserved communities are prioritized communities in achieving equitable water rebalance in California in addition to developing and implementing essential infrastructure and policy changes.