Search for: All records

Understanding inequality in groundwater access and cropland ownership is critical for assessing the sustainability and equity of agricultural systems, especially in regions facing climatic and socioeconomic patterns such as drought and cropland consolidation. These two forms of access are deeply interconnected: for instance, cropland ownership often determines who can access and control groundwater. Due to data challenges, however, few studies have quantified groundwater access inequality in the same ways that land ownership has been quantified. Similarly, the regional scale of most analyses to date limits our understanding of factors that shape and modify these interconnections. Our study aims to address this gap by constructing a novel geospatial dataset by matching groundwater wells with cropland parcels across California’s Central Valley. We quantify the magnitude and spatial patterns of groundwater and cropland inequality and examine how it scales with land ownership, crop types, and surface water access. Our results indicate substantial inequality in both groundwater access and land ownership, with the top decile of well owners possessing 46.4% of the region’s total well capacity. These well owners are more likely to allocate groundwater to high-revenue, water-intensive perennials such as almonds and walnuts. Furthermore, large landholders tend to have far more wells, deeper and higher-capacity wells, and greater access to surface water resources. However, we observe consistently wider inequality in land ownership than water access, and larger landowners possess less well depth and capacity per hectare. We discuss the implications of these findings in the context of California’s historical lack of regulation on groundwater, particularly with respect to inequality in open access vs private property resources. We also consider possible lessons for future groundwater regulation and distribution mechanisms for groundwater rights under California’s Sustainable Groundwater Management Act. 

Groundwater wells are critical infrastructure that enable the monitoring, extraction, and use of groundwater, which has important implications for the environment, water security, and economic development. Despite the importance of wells, a unified database collecting and standardizing information on the characteristics and locations of these wells across the United States has been lacking. To bridge this gap, we have created a comprehensive database of groundwater well records collected from state and federal agencies, which we call the United States Groundwater Well Database (USGWD). Presented in both tabular form and as vector points, the USGWD comprises over 14.2 million well records with attributes such as well purpose, location, depth, and capacity for wells constructed as far back as 1763 to 2023. Rigorous cross-verification steps have been applied to ensure the accuracy of the data. The USGWD stands as a valuable tool for improving our understanding of how groundwater is accessed and managed across various regions and sectors within the United States. 

Abstract Groundwater wells are critical infrastructure that enable the monitoring, extraction, and use of groundwater, which has important implications for the environment, water security, and economic development. Despite the importance of wells, a unified database collecting and standardizing information on the characteristics and locations of these wells across the United States has been lacking. To bridge this gap, we have created a comprehensive database of groundwater well records collected from state and federal agencies, which we call the United States Groundwater Well Database (USGWD). Presented in both tabular form and as vector points, USGWD comprises over 14.2 million well records with attributes, such as well purpose, location, depth, and capacity, for wells constructed as far back as 1763 to 2023. Rigorous cross-verification steps have been applied to ensure the accuracy of the data. The USGWD stands as a valuable tool for improving our understanding of how groundwater is accessed and managed across various regions and sectors within the United States.