Groundwater Sustainability in the South American Subbasin

The Sacramento Central Groundwater Authority (SCGA) works with local agencies to implement California’s Sustainable Groundwater Management Act (SGMA) in the South American Subbasin.

Under SGMA, groundwater basins must be managed sustainably to protect water supplies for communities, agriculture, and the environment. This work is guided by an adopted Groundwater Sustainability Plan (GSP), which outlines how the basin will avoid undesirable results such as chronic groundwater overdraft, land subsidence, and water quality degradation.

Learn more about the adopted Groundwater Sustainability Plan and ongoing implementation efforts below.

Groundwater Sustainability Plan (GSP)

What is a Groundwater Sustainability Plan (GSP)?
A Groundwater Sustainability Plan is a long-term planning document required under California’s Sustainable Groundwater Management Act (SGMA). The GSP describes current basin conditions, sets measurable objectives, and identifies actions needed to achieve sustainable groundwater management over time.

About the South American Subbasin GSP
The South American Subbasin GSP was developed collaboratively by local groundwater sustainability agencies and was approved by the California Department of Water Resources (DWR). The plan establishes a framework for monitoring groundwater conditions, implementing management actions, and reporting progress.

SCGA plays a key coordination and governance role in supporting the implementation of the GSP within the basin.

Adopted GSP & Official Documents

The adopted GSP and its supporting documents are maintained on the South American Subbasin website and the State’s SGMA Portal.
Authoritative sources include:

• Adopted Groundwater Sustainability Plan
• GSP Chapters and Appendices
• DWR Approval Letter
• Annual Reports submitted under SGMA

Access the official GSP documents here

Annual Reports & Ongoing Implementation

Under SGMA, annual reports are submitted to DWR to document basin conditions, groundwater use, and progress toward sustainability. These reports provide transparency and track implementation of the GSP.

View annual reports and SGMA submittals here

Historical Materials

Earlier groundwater planning documents and pre-SGMA materials are available for historical reference. These documents do not reflect the currently adopted GSP.