The State Denies Big Valley Basin’s Ground Water Sustainability Plan


Lassen County Supervisor Alabugh, who sits on the board, along with other county supervisors from Modoc, announced they would have 180 days to make the state’s requested adjustments.

In 2014, California enacted the Sustainable Groundwater Management Act (SGMA). This law allows local groups called groundwater sustainability agencies (GSA) to create plans for taking care of certain groundwater areas in California. The law says that GSAs in areas with serious groundwater problems must ensure the water is managed well to avoid bad outcomes. To do this, they need to create plans that work and think about the needs of everyone who uses the groundwater, including the environment.

The undertaking has cost the counties 100s of thousands of dollars, and despite their best efforts, this year’s plan has been sent back to the drawing board.

The Big Valley Bassin is classified as a “medium” priority basin by the Department of Water Resources. It spans a land area of about 144 square miles in Modoc and Lassen counties, with The Pit River and Ash Creek as major tributaries in the basin.

Per the GSP’s studies and reports on the basin’s water storage, it was concluded that Conditions in the Basin during the 2021 WY remained consistent, stating that even during the dry and critical water years of 2020 and 2021, water elevations at all monitoring wells remained above their measurable objectives.

Further looks at the basin reveal that overall, the storage capacity of the basin has only minimally declined since 2018, and the GSP says, based on the data collected, the basin will remain sustainable well into the future.


Photo: BVGSP AR WY2021 Final Draft Fig. 1.1 Big Valley Groundwater Basin Map