Salinas Valley – Upper Valley Aquifer
Statistics
- Basin Name
- Salinas Valley – Upper Valley Aquifer
- Basin Number
- 3-004.05
- SGMA Basin Priority
- Medium
- Critically Overdrafted
- No
- Hydrologic Region Name
- Central Coast
- Counties
- Monterey
At-A-Glance
Located in California’s Central Coast hydrologic region, the Salinas Valley – Upper Valley Aquifer subbasin is 238,020.54 acres in size. This Medium priority basin is home to an estimated 16,445 people (2010 value). It has approximately 606 wells, of which approximately 30 are water supply wells. Groundwater accounts for approximately 100 percent of the basin’s water supply.
Basin Notes
2003: Bulletin 118 basin description
2007: “Steelhead use of upper Salinas River tributaries is dependent upon the presence of a migration corridor in the main stem Salinas River. One of the main limitations to migration within the Salinas River Basin is the limited availability of adequate flows … The number of days within the migration period where flows are adequate for migration is highly variable from year to year, and groundwater pumping has shortened this window … Spring flows declined substantially following increased pumping of groundwater for agricultural production.” Source: Biological Opinion, Salinas Valley Water Project, National Marine Fisheries Service, June 21, 2007
2014: CASGEM Basin Prioritization: medium “Upper Valley Aquifer groundwater recharge uniquely linked to reservoir releases. The pattern of storage change is similar to that of the Forebay Subarea, with a similar apparent reliance on reservoir releases … If reservoir releases are severely curtailed, storage losses on the order of 50,000 to 70,000 afy, or about 30-50% of annual pumping would occur.” Source: State of the Salinas River Groundwater Basin Report, 10 December 2014
2015: Monterey County Water Resources Agency SGMA timeline
2018: Draft priority: High. Comment – Declining groundwater levels. See State of the Salinas River Groundwater Basin, Monterey County Water Agency, January 16, 2015 Basin boundary request with Paso Robles Area subbasin 3-004.06 pending.
2019: Basin boundary modification approved. Extended the shared boundary of the Upper Valley Aquifer and Paso Robles Area subbasins to coincide with the Monterey and San Luis Obispo county line. Expansion changed basin priority from High to Medium.
2022: January 24 – GSP submitted to DWR
2023: April 27 – DWR approved GSP