This study for the state Delta Protection Commission compared the effectiveness of using new remotely sensed measurement technology to estimate farmers' "consumptive water use," or the amount of irrigation water crops transpire and evaporate from the nearby soil. Current methods of estimation and reporting of consumptive water use can be time-consuming and costly. The State Water Resources Control Board requires farmers to report the data for each water diversion every three years. FINDINGS: Remote sensing measurements using SEBAL: (1) Provide accurate estimates of evapotranspiration that are less susceptible to human error; (2) Are an efficient and consistent way to acquire data for estimation; no need to aggregate crop growth characteristics, irrigation practices and other field information; (3) Offer a promising and practical alternative to crop coefficent methods of estimating evapotranspiration.