Implementing California’s Sustainable Groundwater Management Act in Yolo County

Drawing on SEI’s years of experience in guiding stakeholder-driven processes through the Robust Decision Support (RDS) practice, researchers have helped Yolo County, California comply with the state’s Sustainable Groundwater Management Act (SGMA) since 2016.

In earlier years, SEI led a team in using RDS to help Yolo County prepare for the implementation of SGMA, which requires California water agencies to halt the overdraft of priority basins and implement sustainability plans. This phase of the work included an assessment of local farmer attitudes on groundwater management, the development of an integrated hydro-economic model, and the implementation of the RDS process with Yolo County stakeholders and its use in the development of their Groundwater Sustainability Plan in 2022.

The WEAP–MODFLOW model developed by SEI allows the Yolo Subbasin Groundwater Agency to simulate both surface and groundwater processes and their interactions in both agricultural and urban areas in the Yolo subbasin. SEI continues to support the agency by refining the model, adding new WEAP capabilities and developing a seasonal forecast model for hydrological conditions and water supply operations. Researchers are also working on modeling future project management actions and demand management scenarios.

As a result of this years-long collaboration, Yolo County water managers have a tool to track and plan for more informed water use and can explore the impact of different climate and demand management scenarios.