Drought Water Rationing Necessitates an Equitable and Multidimensional Approach: Evidence from California

Since 2011 many areas across California have experienced their driest years on record, with conditions barely improving since then. Reservoirs and snowpack water content have recorded some of the lowest measurements ever, with users (individuals, towns and cities) using groundwater to buffer the potentially devastating effects of the drought. Among other strategies, rationing has been one of they key interventions that the state has adopted to better manage its water resources. April 1st 2015 marked the first day in California's history when mandatory water reductions were instated statewide. By executive order, Governor Brown directed the State Water Resources Control Board to impose a 25% reduction on California's 400 local water supply agencies, which serve 90% of California residents. Since then, local agencies have been responsible for allocating restrictions to reduce water consumption and monitor compliance. A variety of research organizations and media outlets have begun exploring the equity considerations of the drought, but their analyses are often one-dimensional (water consumption per capita). Here we explore the multi-dimensional dynamics of rationing and drought in California using Census and California Water Resources Board data for over 300 communities in the state. We use data mining, parallel coordinates, and a nearest neighbors clustering algorithm to explore relationships between rationing and community spatial distribution, weather, drought related climate variables, economic sector employment, race, localized income inequality, household size, and income. The data suggests that there are nine distinct rationing groups across the state, that rationing was performed without taking into account the localized effects of the drought (hard hit communities rationing as much as less affected communities), that severely drought affected low-income communities (using SPI and SPEI 3 year indices) were asked to ration as much (and sometimes more) than less drought affected high-income communities, and that even after tight conservation standards on large consumers, high-income communities still consumed 30% more water per capita than low-income communities. We conclude with a suggested framework for how more equitable rationing could be implemented in the future.