The “Paso Robles Area Subbasin” of the Salinas Valley Groundwater Basin (locally referred to as the “Paso Robles Groundwater Basin” - see DWR Bulletin 118 Basin No. 3-004.06, lies in northern San Luis Obispo County following boundary modifications which removed the portion in Monterey County in early 2019. The subbasin is bounded by the Santa Lucia Range on the west, the La Panza Range on the South, and the Temblor and Diablo Ranges on the east. The basin overlies approximately 436,000 acres (681 square miles).