Groundwater Sustainability Plan for Big Valley (Lake County) Basin

The purpose of this Groundwater Sustainability Plan (GSP) is to verify and maintain sustainable groundwater management in the Big Valley Groundwater Basin (Basin Number 5-015) by meeting the regulatory requirements set forth in the three-bill legislative package: Assembly Bill (AB) 1739 (Dickinson), Senate Bill (SB) 1168 (Pavley), and SB 1319 (Pavley) collectively known as the Sustainable Groundwater Management Act of 2014 (SGMA).

Under SGMA, high- and medium-priority basins not identified as critically overdrafted must develop and submit a GSP to the California Department of Water Resources (DWR) by January 31, 2022. GSPs are prepared and implemented by Groundwater Sustainability Agencies (GSA) that are formed from local agencies or combinations of local agencies as outlined in CWC § 10723, with the goal to reach sustainability within 20 years of implementing the sustainability plans. SGMA defines sustainable groundwater management as “management and use of groundwater in a manner that can be maintained during the planning and implementation horizon without causing undesirable results.”

Big Valley Basin was identified as a medium-priority basin by DWR based on components such as population and groundwater use; therefore, it is subject to SGMA. The Big Valley Basin GSP is being developed by the Lake County Watershed Protection District (District), which serves as the sole GSA in the Big Valley Basin. The Big Valley GSA has jurisdiction over most of the region, excluding the portion containing the Big Valley Rancheria which is governed by the Big Valley Band of Pomo Indians of the Big Valley Rancheria, a federally recognized tribe.

Due to size, the file is divided into four parts.

Part 1, Part 2, Part 3, Part 4

Plan approved by DWR 4/27/23