Assessing virtual water trade and inequalities in household water footprints across California’s counties

• Inter-county trade only mitigates water shortages in California's South Coast. • The Central Valley export significant virtual water via water-intensive crops. • Higher income groups have a larger per capita water footprint than lower ones. • Policies needed to combine geographic and socioeconomic factors in water saving. A bstract The concept of virtual water trade suggests water flows from water-rich to water-scarce regions, but local disparities are often overlooked. This study uses a multi-regional input-output (MRIO) model to assess virtual water transfers among California's 58 counties and the rest of the conterminous U.S. in 2017. Results show the Central Valley exported large volumes of virtual water via water-intensive crops (e.g., fruits and vegetables) but imported water embodied in industrial, mining, and thermoelectric processes. These imports eased water stress in the Central and South Coast but left Central Valley scarcity unresolved. Linking household consumption with MRIO reveals the highest-income group (US$200k+) had per capita water footprints 1.8 times larger than the lowest-income group (below US$15k). Although household size and consumption patterns mitigated this gap, Central Valley's high water intensity fueled excessive footprints. The study underscores the need for targeted, equitable water management policies, promoting more effective water conservation strategies.