The Livermore Valley AVA is an American Viticultural Area in Alameda County, California, surrounding the city of Livermore in the Tri-Valley region. Both the AVA and the city are named after Robert Livermore, a landowner whose holdings encompassed the valley. The groundwater basin underlying the valley is the Livermore Basin, the largest sub-unit of which is the Mocho Subbasin. The Livermore Basin is one of five aquifers in the San Francisco Bay Area that supply most of the metropolitan Bay Area population.