Court Affirms Local Agencies’ Authority to Determine Geographic Boundaries for WSAs

Abstract

A California appellate court recently held that the California Water Code does not mandate a particular analytical method to assess whether groundwater supplies are sufficient to meet the projected demand of a proposed development project. If the water supply for a proposed project includes groundwater, section 10910 of the California Water Code requires a public water agency to prepare a water supply assessment (WSA). The court ruled that a WSA is not inadequate as a matter of law simply because the WSA's study area did not precisely conform to the boundaries of a groundwater basin or subbasin. The court determined that the water supplier has substantial discretion in determining how to measure groundwater sufficiency. If the study area is based on empirical data and there is a rational reason for choosing the boundary, the WSA is legally adequate.