Sacramento Valley – Yolo
Statistics
- Basin Name
- Sacramento Valley – Yolo
- Basin Number
- 5-021.67
- SGMA Basin Priority
- High
- Critically Overdrafted
- No
- Hydrologic Region Name
- Counties
- Solano, Yolo
At-A-Glance
Located in California’s Sacramento River hydrologic region, the Sacramento Valley – Yolo is 540,693.50 acres in size. This High priority basin is home to an estimated 200,219 people (2010 value), which have been at a rate of 25.
Sacramento Valley – Yolo is a(n) basin with approximately 6755 wells, of which approximately 189 are water supply wells. Groundwater accounts for approximately 39 percent of the basin’s water supply.

Basin Notes
2003: Bulletin 118 basin description
2014: CASGEM basin prioritization – high. Comment: Localized TDS problems preclude using GW for some M&I uses without treatment. Some subsidence in northeast of Davis and in northern Yolo. GW Use based on Yolo County, California’s Water Supply System: Conjunctive Use Without Management, UC Davis, 1992
2016: Basin boundary modification with Colusa 5-021.52, Capay 5-021.68, and Solano 5-021.66 subbasins
Revised basin boundary description
Yolo Groundwater Sustainability Agency on consolidation of the Capay Valley 5-021.68, and portions of the Colusa 5-021.52, Yolo 5-021.67, and Solano 5-021.66 subbasins that lie within Yolo County and a boundary adjustment along the Yolo County line.
2018: Draft basin prioritization – high. Groundwater levels and subsidence comments:
- 1) CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR 2) The areas of continuing overdraft in the County cover most of the Lower Cache-Putah and western Colusa sub-basins. To some extent improvements from reduced pumping have occurred in the DWD area of Colusa sub-basin. Particular overdraft spots include the Yolo-Woodland area on both sides of Cache Creek, areas between Zamora and Yolo, and areas to the northeast of Davis. These areas coincide with places where subsidence and/or deteriorating groundwater quality have been measured. Source: Yolo County, California’s Water Supply System: Conjunctive Use without Management, UC Davis, 1992
- 1) Zamora Land Subsidence Extensometer (11N01E24Q008M), Conaway Extensometer (09N03E08C004M), DWR Water Data Resources; JPL/ NASA Caltech report 2015-16
Groundwater-related transfer “Type A” in which local groundwater is pumped to compensate for water exports.
2019: Basin boundary modification. Phase 2 draft priority: high