Sacramento Valley – Solano

Statistics

At-A-Glance

Located in California’s Sacramento River hydrologic region, the Sacramento Valley – Solano subbasin is 354,672.90 acres in size. This Medium priority basin is home to an estimated 116,125 people (2010 value). It has approximately 4086 wells, of which approximately 130 are water supply wells. Groundwater accounts for approximately 25 percent of the basin’s water supply.

Source: CA DWR
Source: CA DWR

Basin Notes

2003Bulletin 118 basin description

2014: CASGEM basin prioritization – medium

2016Basin boundary modification with Yolo 5-021.67, Colusa 5-021.52 and Capay 5-021.68 Sacramento Valley subbasins approved.

2018: Basin draft priority – high. Groundwater levels and salt intrusion comments:

  • 1) CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR 2) The Solano Project was developed to help mitigate the declining groundwater elevations in Solano County. Source: Solano County Water Agency / Local Conditions
  • 1) Numerous upstream storage facilities, together with diversions of water from the Delta and the tributary streams of the Delta have substantially reduced the amount of fresh water flowing into the Delta with a resultant increase in salinity intrusion into the Marsh and Delta. …The following policies represent the County’s intent in preserving water quality and reducing flood hazards in the Suisun Marsh: SM.P-11: Projects designed to import or redistribute the fresh water in the Marsh for salinity control should be planned carefully so that the expected benefits are realized. SM.P-12: To prevent crop damage in some areas, the withdrawal of groundwater from the aquifers surrounding the Marsh may be desirable. Withdrawal should not be so extensive as to allow the salt water of the Marsh to intrude into fresh water aquifers, or to disrupt the natural subsurface flow of groundwater into the Marsh. Source: Suisun Marsh Draft General Plan

2019: Basin boundary modification revised the internal boundary line between Yolo and Solano subbasins to bring Yolo County Reclamation Districts 150, 307, and 999 into the Yolo Subbasin.

Phase 2 draft basin priority: high

2022: January 27 – GSP submitted to DWR

2024: January 18 – DWP approved GSP

GSA Information