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.