Sacramento Valley – Yolo

Statistics

Basin Name

Basin Number

5-021.67

SGMA Basin Priority

High

Critically Overdrafted

Hydrologic Region Name

Sacramento River Hydrologic Region

Counties

Solano, Yolo

Adjacent Basins

Sacramento Valley - Colusa 5-021.52, Sacramento Valley - Sutter 5-021.62, Sacramento Valley - Solano 5-021.66, Sacramento Valley - South American 5-021.65,

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.

Source: CA DWR

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