Water Scarcity and Inter-Regional Trade in the U.S.: A Multiple Spatial Scale Analysis

Abstract

Water scarcity is an increasingly pressing challenge in the United States, driven by the compounded effects of climate change, population growth, resource overexploitation, and inadequate management practices. While the U.S. is not typically considered water-stressed, significant regional disparities and localized vulnerabilities highlight the urgent need for comprehensive analyses of water use and management. This study addresses critical research gaps, including the limited scope of existing models, inadequate data resolution, underexplored socioeconomic impacts, and overlooked spillover effects, through a multi-scale evaluation of water use and constraints across the U.S., with a particular focus on California.This study explores the land-water nexus across the U.S., revealing the environmental and economic trade-offs inherent in interregional agricultural trade. Utilizing a state-level multi-regional input-output (MRIO) model, this study uncovers how interstate trade alleviates cropland scarcity in coastal regions while intensifying water scarcity in arid areas like California. The findings emphasize California’s dual role as a land importer and water exporter, highlighting the need for water conservation policies that integrate economic productivity with environmental sustainability. This study also examines California’s county-level water use dynamics, focusing on inter-county disparities in virtual water flows and the socioeconomic drivers of household water demand. By linking a county-level MRIO model with household consumption data, the study identifies significant inequalities in water footprints across regions and income groups. Higher-income households exhibit larger water footprints due to their increased household consumption, while agriculturally intensive areas like the San Joaquin Valley bear the burden of exporting virtual water to the demand in urbanized regions. These findings underscore the need for equitable and region-specific water management strategies. Additionally, this study evaluates the economic, employment, and environmental impacts of water constraints in California, particularly in the context of the state’s transition to regulated water management. By employing a water-supply-constrained MRIO model, it assesses the implications of various climate and policy scenarios, highlighting the far-reaching spillover effects of water constraints across California’s interconnected economy. This evaluation framework offers a transferable tool for addressing water scarcity challenges in other water-stressed regions globally. Collectively, this research advances the understanding of water use and management across multiple spatial scales, providing critical insights for designing sustainable, equitable, and region-specific water policies. By focusing on California as a case study, it sheds light on broader national water challenges and contributes to the development of strategies that promote resilience and sustainability under evolving climate and socioeconomic pressures.