Sacramento Valley – South American
Statistics
- Basin Name
- Sacramento Valley – South American
- Basin Number
- 5-021.65
- SGMA Basin Priority
- High
- Critically Overdrafted
- No
- Hydrologic Region Name
- Sacramento River
- Counties
- Sacramento
Basin Notes
2003: Bulletin 118 basin description
2014: CASGEM basin prioritization – high. Comment from B118: Montgomery Watson (1997) listed seven sites within the subbasin with significant GW contamination. From Sac County GWMP: Overall decreasing GW level trend over past 50 years (~30ft).
2016: Basin boundary modification request by Omochumne-Hartnell Water District San Joaquin Valley – Cosumnes subbasin. Per DWR: This request was submitted as both a scientific internal and jurisdictional internal modification. However, the request did not provide necessary scientific information to meet basin boundary definition requirements, therefore it was evaluated solely as a jurisdictional modification. Based on Sacramento County comment the modification request was denied. Border change noted as part of Yolo County boundary modification.
Revised basin boundary description
Sacramento County GSP alternative proposal. Analysis of basin conditions submitted to DWR.
2018: Draft basin priority – high. Comments: 1) CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR 2) Sacramento Central Groundwater Authority Groundwater Elevation Monitoring Plan CASGEM monitoring plan (February 2012) states in that the intensive use of the groundwater basin has resulted in a general lowering of groundwater elevations near the center (or centroid) of the basin away from the sources of recharge. Basin boundary modification request to create a new subbasin in the northern portion of the Delta involving the Solano subbasin 5-021.66 and Eastern San Joaquin Valley subbasin 5-022.01 pending with DWR. Northern Delta Groundwater Sustainability Agency webpage on basin boundary modification.
2022: January 27 – Groundwater Sustainability Plan (GSP) submitted to Department of Water Resources (DWR)
2023: July 27 – GSP approved by DWR
At-A-Glance
California Water Library Documents About This Basin
Assessing Causes and Consequences of Winter Surface Water Dynamics in California's Central Valley Using Satellite Remote Sensing
Wiley Online Library | June 3rd, 2025
California's Central Valley is increasingly vulnerable to winter floods. A comprehensive spatial baseline of flood extents is critical for inundation analyses that can en
Property Prices in Peril
First Street | February 3rd, 2025
Regional desirability is being reshaped by chronic changes in climate across the country: coastal areas are increasingly threatened by sea level rise, while inland region
Groundwater sustainability and land subsidence in California’s Central Valley
Water (MDPI) | April 22nd, 2024
The Central Valley of California is one of the most prolific agricultural regions in the world. Agriculture is reliant on the conjunctive use of surface-water and groundw
Statement of Findings regarding the Approval of the Sacramento Valley - South American Subbasin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | July 27th, 2023
Subsurface water flux in California's Central Valley and its source watershed from space geodesy
American Geophysical Union (AGU) | September 29th, 2022
We combine measurements from Global Positioning System positioning and Gravity Recovery and Climate Experiment gravity to infer change in water components in Central Vall
Status and understanding of groundwater quality in the Sacramento Metropolitan Domestic-Supply Aquifer study unit, 2017—California GAMA Priority Basin Project
U.S. Geological Survey (USGS) | May 26th, 2022
Groundwater quality in the Sacramento Metropolitan Domestic-Supply Aquifer study unit (SacMetro-DSA) was studied from August to November 2017 as part of the second phase
South American Subbasin Groundwater Sustainability Plan
Sacramento County | October 29th, 2021
Groundwater management in the South American Subbasin (SASb) has been occurring for decades. Stable groundwater conditions in terms of groundwater levels, storage volume
Post-Drought Groundwater Storage Recovery in California's Central Valley
American Geophysical Union (AGU) | October 5th, 2021
California's Central Valley has experienced chronic groundwater depletion over the past few decades, the rate of which was amplified by droughts in 2007–2009 and 2012?
Critical Aquifer Overdraft Accelerates Degradation of Groundwater Quality in California's Central Valley During Drought
American Geophysical Union (AGU) | September 1st, 2021
It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood.
Geologic Influences on the Quality of Groundwater Used for Domestic Supply in the Northern Sierra Nevada Foothills
U.S. Geological Survey (USGS) | May 25th, 2021
Approximately 2 million California residents depend on groundwater from domestic wells for their drinking-water supply. The State of California, in collaboration with the
Domestic well vulnerability to drought duration and unsustainable groundwater management in California's Central Valley
Environmental Research Letters (IOP) | March 18th, 2020
Millions of Californians access drinking water via domestic wells, which are vulnerable to drought and unsustainable groundwater management. Groundwater overdraft and th
2017 SGMA Annual Report South American Subbasin (5-021.65) Sacramento Central Groundwater Authority
Sacramento Central Groundwater Authority | April 1st, 2018
The Sacramento Central Groundwater Authority (SCGA) has prepared an Annual Report describing groundwater conditions in the South American Subbasin for the 2017
A hybrid machine learning model to predict and visualize nitrate concentration throughout the Central Valley aquifer, California, USA
Science of the Total Environment (Elsevier) | June 9th, 2017
Intense demand for water in the Central Valley of California and related increases in groundwater nitrate concentration threaten the sustainability of the groundwater res
Hydrology, Hydraulics, and Water Management Technical Report
U.S. Bureau of Reclamation (USBR) | December 15th, 2014
This Technical Report describes pertinent hydrologic and hydraulic condition and water management operations for Shasta Lake, the Sacramento River, the Delta, and the CVP
Geochemistry of Ground Water in the Sacramento Valley, California
U.S. Geological Survey (USGS) | July 13th, 1984
A geochemical investigation was done to evaluate temporal changes in water quality and to determine the processes that control water chemistry in shallow ground water of