The SGMA is codified as Part 2.74 (Sustainable Groundwater Management Act) of the California Water Code (Section 10720 et seq).  The regulations adopted to enforce the provisions of the Act are found in Section 350 et seq, Division 2, Chapter 1.5, Subchapter 2 of Title 23 of the California Code of Regulations.  The Sustainable Groundwater Management Act (SGMA) became effective January 1, 2015. More information can be found on DWR’s website.

In Modoc County, the Act pertains to the Big Valley Groundwater Basin and the Tulelake Sub Basin, which have been designated as “medium priority” basins by DWR.  This designation as a medium-priority basin requires the preparation of a GSP under the Act.  All other groundwater basins in Modoc County, other than Big Valley and the Tulelake Sub Basin, are currently designated as “low” or “very low”.  This means that, at least for now, no actions are required pursuant to SGMA for any basin other than Big Valley. More information about DWR’s basin prioritization can be found here.

The SGMA was created to ensure groundwater basins throughout the state are managed to reliably meet the needs of all users while mitigating changes in the quality and quantity of groundwater. The intent of the Act as described in section 10720.1 of the Water Code is to:

  • Provide for the sustainable management of groundwater basins.
  • Enhance local management of groundwater consistent with rights to use or store groundwater.
  • Establish minimum standards for sustainable groundwater management.
  • Provide local groundwater agencies with the authority and the technical and financial assistance necessary to sustainably manage groundwater.
  • Avoid or minimize subsidence.
  • Improve data collection and understanding about groundwater.
  • Increase groundwater storage and remove impediments to recharge.
  • Manage groundwater basins through the action of local governmental agencies to the greatest extent feasible, while minimizing state intervention to only when necessary to ensure that local agencies manage groundwater in a sustainable manner.

The role of the GSA is to create a GSP and then implement and enforce that plan. The plan must include measurable objectives that can be used to demonstrate the basin is sustainably managed within twenty (20) years of implementation.

County’s Role in GSA Formation
The legislative intent of SGMA is to recognize and preserve the authority of cities and counties to manage groundwater pursuant to their existing powers. As such, local governments play an important land use and water management role in California and should be involved in GSA formation and GSP implementation.

CASGEM Basin Prioritization Process

There are 515 alluvial groundwater basins and subbasins in California as defined in DWR's Bulletin 118. These basins contribute close to 40 percent of California's annual water supply in an average year and as much as 45 percent in dry years. During extensive dry or drought years, groundwater can provide close to 60 percent of the water supply. Statewide, approximately 30 million people, or 80 percent of Californians, live in areas overlying alluvial groundwater basins. Some communities are 100 percent reliant on groundwater.

The California Department of Water Resources (DWR) implemented the California Statewide Groundwater Elevation Monitoring (CASGEM) Program in response to legislation enacted in California's 2009 Comprehensive Water package. As part of the CASGEM Program and pursuant to the California Water Code (CWC §10933), DWR is required to prioritize California groundwater basins, so as to help identify, evaluate, and determine the need for additional groundwater level monitoring.

The CWC requires a statewide prioritization of California's groundwater basins using the following eight criteria:

  1. Overlying population;
  2. The projected growth of the overlying population;
  3. Public supply wells;
  4. Total wells;
  5. Overlying irrigated acreage;
  6. Reliance on groundwater as the primary source of water;
  7. Impacts on the groundwater; including overdraft, subsidence, saline intrusion, and other water quality degradation; and
  8. Any other information determined to be relevant by the Department.
Component 8 was amended in 2019 to the following:
      8. Any other information determined to be relevant by the department, including adverse impacts on local habitat and local streamflows.

DWR incorporated new data, to the extent data are available8, and the amended language of Water Code Section 10933(b)(8) (component 8) to include an analysis of adverse impacts on local habitat and local streamflows as part of the SGMA 2019 Basin Prioritization.
The following information was deemed relevant and considered as part of component 8 for the SGMA 2019 Basin Prioritization based on SGMA:
• Adverse impacts on local habitat and local streamflows.
• Adjudicated areas.
• Critically overdrafted basins.
• Groundwater-related transfers.

Click Here to download the 2019 SGMA Basin Prioritization Process and Results Document

The CASGEM Groundwater Basin Prioritization (Basin Prioritization) is a statewide ranking of groundwater basin importance that incorporates groundwater reliance and focuses on basins producing greater than 90% of California's annual groundwater. Although the results are a statewide assessment; it is important to recognize the statewide findings are not intended to diminish the local importance of groundwater including in the smaller size or lower-use groundwater basins.

The Modoc County Board of Supervisors established a Groundwater Resources Advisory Committee to provide local input into the process of implementing SGMA. The Groundwater Resources Advisory Committee meets on the fourth Thursday of every month beginning in February of each year, except for December, when the meeting shall be held on the second Thursday.

For GRAC agenda and information regarding the meetings CLICK HERE

Modoc County Medium Priority Basins
Subbasin Name: TULELAKE
For more information on the Tulelake Subbasin or to access the agendas and minutes of the Tulelake Core Team, CLICK HERE.

Basin Name: BIG VALLEY
For more information on the Big Valley Groundwater Basin or to access the agendas and minutes of the Big Valley Advisory Committee visit the Big Valley Groundwater Basin page.

Modoc County Low or Very Low Priority Basins