Sustainable Groundwater Management Act (SGMA)

From its development in the legislature to local implementation, Downey Brand has been continually involved with the Sustainable Groundwater Management Act (SGMA) of 2014. As this landmark change in California’s water law unfolds, our attorneys remain at the forefront. The materials on this page provide an overview of the law and key information associated with its implementation.

SGMA Overview and Reference Guide

The Sustainable Groundwater Management Act was enacted in 2014 and became effective January 1, 2015. The goal of the legislation is to bring groundwater basins that are designated as medium or high priority basins into sustainability—where inflows (recharge) match outflows (pumping) on a long-term basis and groundwater storage is maintained. The Sustainable Groundwater Management Act will have lasting implications on water users throughout the State. Downey Brand’s water law practice has created a helpful reference guide for professionals in the water industry—A Compendium of California’s Sustainable Groundwater Management Act

This guide includes the following critical resources in one readily-accessible location:

  • The current text of SMGA from SB1168 (Pavley), AB1739 (Dickinson), SB1319 (Pavley), AB 617 (Perea), AB 939 (Salas), SB 562 (Cannella), and SB 2874 (Gaines);
  • Basin Boundary Regulations (Cal. Code Regs. tit. 23, § 340-346.6);
  • Groundwater Sustainability Plan Regulations (Cal. Code Regs. tit. 23, § 350-358.6); and
  • Streamlined Adjudication Statutes (Code of Civ. Proc. § 830-852).

Groundwater Basins Subject to SGMA

In total there are 431 groundwater basins in California.  Of those, 24 are subdivided into a total of 108 subbasins, providing a total of 515 distinct groundwater systems.  (California’s Groundwater, Bulletin 118, 2003 Update, California Department of Water Resources (October, 2003).)

Each basin and subbasin in California has been prioritized as low, medium, or high priority by the California Department of Water Resources using the following eight criteria: 1. Overlying population; 2. Projected growth of 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. This metric provides an indicator of the importance of groundwater as a resource within the basin. If a large and growing population, for example, relies on groundwater for its supply, and the basin is also taxed by significant pumping for irrigated acreage, the groundwater resource is of the utmost importance and the basin will be designated a high priority basin.

Here is a map of the Department of Water Resources’ 2019 prioritization of groundwater basins in California and a report by DWR about its prioritization process (click on the map to view a larger PDF).

Map of DWR Prioritization of groundwater basins in CA

DWR has also identified 21 critically over drafted basins (click on the map below to view a larger PDF):

  1. Santa Cruz Mid-County
  2. Corralitos – Pajaro Valley
  3. Salinas Valley -180/400 Foot Aquifer
  4. Salinas Valley – Paso Robles Area
  5. Los Osos Valley – Los Osos Area
  6. Cuyama Valley
  7. Santa Clara River Valley – Oxnard
  8. Pleasant Valley
  9. San Joaquin Valley – Eastern San Joaquin
  10. San Joaquin Valley – Merced
  11. San Joaquin Valley – Chowchilla
  12. San Joaquin Valley – Madera
  13. San Joaquin Valley – Delta-Mendota
  14. San Joaquin Valley – Kings
  15. San Joaquin Valley – Westside
  16. San Joaquin Valley – Kaweah
  17. San Joaquin Valley – Tulare Lake
  18. San Joaquin Valley – Tule
  19. San Joaquin Valley – Kern County
  20. Indian Wells Valley
  21. Borrego Valley – Borrego Springs

Map of groundwater basins subject to critical conditions of overdraft

Groundwater Sustainability Agencies

To comply with SGMA, certain local agencies may elect to become a groundwater sustainability agency (GSA) with the authority to manage a particular groundwater basin. Water Code, § 10725.2(a). Management will occur pursuant to a groundwater sustainability plan (GSP) or plans that outline how the basin will be managed in the long term.

SGMA requires the formation of GSAs in medium- and high-priority groundwater basins. GSAs must then develop and implement GSPs to achieve groundwater sustainability. Notices that local agencies have submitted to DWR to date are here.

Groundwater Sustainability Plans

Local agencies that elect to become a GSA will be tasked with developing a GSP and identifying and implementing the sustainability goal. Water Code, § 10727. In establishing this goal, GSAs must “consider the interests of all beneficial uses and users of groundwater.” Water Code, § 10723.2. Further, SGMA affords local agencies that elect to become a GSA and that develop a GSP with additional authority and tools to enforce groundwater management in their service areas. See Water Code, § 10725 et seq.; 10730 et seq. For example, SGMA grants GSAs the ability to curtail groundwater pumping; regulate the spacing of groundwater wells; require registration of groundwater facilities; monitor groundwater extractions; and impose standards on new groundwater well construction). If local agencies do not elect to become GSAs, or fail to submit and implement a sufficient GSP, the State of California may assume these powers.

GSPs for critically overdrafted basins were due on January 31, 2020; those for non-critically overdrafted basins are due January 31, 2022. GSPs submitted to date are available here.

For basins with multiple GSAs that will implement multiple GSPs, SGMA requires a coordination agreement to be executed by the GSAs to ensure that the plans utilize the same data and methodologies. Coordination agreements that have been submitted to DWR are available here.


SGMA allows local agencies to submit alternative plans in lieu of a GSP. DWR approved alternative plans in the following basins:

  • Niles Cone Subbasin
  • Indio Subbasin
  • Mission Creek Subbasin
  • Pajaro Valley Subbasin
  • Santa Clara Subbasin
  • Llagas Area Subbasin
  • Tahoe South Subbasin
  • Coastal Plain of Orange County Basin
  • Livermore Valley Basin

A list of alternative plans submitted is available here and DWR’s evaluation of the alternative plans is available here.

Streamlined Adjudications

There are currently 22 adjudicated basins in California, mostly in Southern California. The Scott River system, near the Oregon border, was adjudicated to help resolve a surface water controversy. The Seaside Basin, near the Monterey Peninsula, was adjudicated after annual pumping was in excess of safe yield and posed a risk for seawater intrusion. The remaining adjudications have all been in Southern California, where development pressures quickly overwhelmed limited aquifers. The remaining adjudicated basins are: Beaumont Basin (2004), Brite Basin (1970), Central Basin (1965), Chino Basin (1978), Cucamonga Basin (1978), Cummings Basin (1972), Goleta Basin (1989), Main San Gabriel Basin: Puente Narrows (1973), Mojave Basin Area (1996),

A year after SGMA was enacted, the legislature enacted a new set of procedures for streamlining groundwater adjudications. One streamlined adjudication has been initiated in California in the Los Posas Basin in Ventura County. The case is currently pending in the Superior Court for the County of Santa Barbara.

9 Attorneys

David R. E. Aladjem


Sacramento 916.520.5361

Nicolas D. Chapman


Sacramento 916.520.5466


Sacramento 916.520.5212

Andrea P. Clark


Sacramento 916.520.5424

Brian E. Hamilton


Sacramento 916.520.5340

Meredith E. Nikkel


Sacramento 916.520.5211

Kevin M. O’Brien


Sacramento 916.520.5235

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Jake R. Voorhees


Sacramento 916.520.5322


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