This paper uses data from the California Department of Water Resources and the United States Department of Agriculture to map county-level variations in water productivity metrics across California. Five different water productivity metrics are used, including gross economic water productivity (EWPg), net economic water productivity (EWPn), irrigated cash rent premiums (RP), green water footprint (GWF), and water intensity (WI). Results show that the average EWPn across California is 608 USD/acre-foot, with significant county-level differences across the state. Most significantly, the average EWPn for all coastal counties was 1,754 USD/acre-foot, while the average EWPn for inland counties was 36 USD/acre-foot, indicating that coastal counties in California have much higher net returns per unit of water consumed than inland counties. Variables such as crop mix, drought index values, and labor costs help describe the large variations in economic water productivity across the state. Net economic water productivity can be used to correctly compensate farmers for voluntary reductions in agricultural water use, and results identify regions where compensation payments would be low or high. The county- level analysis identifies several counties in Southern California, including San Bernardino, Riverside, Imperial, and Inyo counties, where water conservation should be targeted.