UC Santa Cruz
Associate Researcher, Center for International, Global and Regional Studies

Groundwater is a critical resource in California, providing approximately thirty percent of the state’s water supply and significantly more during dry years.

There is no permit system for groundwater withdrawals and all landowners overlying a basin have a correlative right to pump with limited restrictions. The problem is that the groundwater withdrawn, especially during California’s periodic droughts, generally exceeds recharge, contributing to declines in groundwater levels in many areas with associated negative impacts.

Local management agencies, special act districts, and court adjudications are the institutional arrangements to manage groundwater in California. In 2014, the Sustainable Groundwater Management Act (SGMA), established new requirements for 127 basins in, or vulnerable to, overdraft to develop sustainable management programs with increased state oversight.

But SGMA exempted 388 low priority basins and 29 adjudicated (or pending adjudication) basins. In adjudication, a court determines water rights between competing users, may limit the water usage of pumpers, and may establish a “safe yield” for the basin (the amount of groundwater that can be extracted without harm to the rights of water users or the basin).

Prior research differs regarding the efficacy of the adjudicatory process, and there is limited analysis of the complexity of adjudicated water rights and the current condition of the state’s adjudicated basins. We are completing a survey of the 29 completed and pending adjudications for the SWRCB, and we request matching funds to evaluate whether adjudication, as an institutional approach to managing groundwater, aligns with SGMA, and supports sustainable and inclusive management outcomes.

UC Water Connection: 

Dr. Langridge was awarded a 2016 UC Water match grant to support her ongoing research on "Adjudicated Basins and the Sustainable Management of Groundwater." 


Ruth Langridge’s expertise is California water law and policy and her research focuses on the processes and relations that enable access to water and create resilience to water scarcity; on the legal and institutional issues related to water supply planning and groundwater management; and on water supply security under climate change.

Ruth Langridge is an Associate Researcher with the Center for International, Global and Regional Studies at the University of California, Santa Cruz and a Continuing Lecturer with the Legal Studies Program. She is currently the Principal Investigator of the Groundwater Adjudication Project that is assessing all current and pending adjudications and special act districts in California to evaluate the processes and outcomes of these institutions for managing groundwater. Additional research is focused on climate change, drought and water supply security. She is the lead author of a report detailing the hydrogeophysical, legal-institutional, and socio-political dimensions of establishing local groundwater drought reserves that was incorporated into California’s 2012 Vulnerability and Adaptation study. Her research is funded by state and federal agencies and foundations. She has presented her work on groundwater to state and federal agencies and legislators, and just completed a three-year term as a member of the CA Department of Water Resources Climate Change Technical Advisory Committee.