Energy and water use in irrigated agriculture during drought conditions

Abstract

Energy requirements for irrigation vary widely across California as a function of the proximity of water sources, the methods of irrigation, and the water requirements of the crops. The objectives of this study are to determine water and energy use for agricultural irrigation and during the 1977 season; describe the responses of agriculture to the drought conditions of 1977; and identify the present and potential water and energy conservation sstrategies applicable to California. The analysis of electricity and water requirements for irrigated agriculture was started as a part of a two-phase project. The purposes of the overall study are to assess the impacts of the drought on California electricity supply and demand, to evaluate remedial measures, and to develop a methodology for such assessments. The methodology used for determining electricity requirements to pump irrigation water focuses on the hydrologic basins of the Central Valley. The method employs several factors to calculate the final energy demand for pumping. The factors include unit energy use to obtain ground and surface water, average water use by individual crop, type of irrigation, and estimated crop acreage planted in 1977. Section II (''Energy/Water Use During Drought Year'') contains the assumptions and calculations used to determine the total electricity demand. The dry years of 1976 and 1977 present an opportunity to gain a better understanding of how farmers meet their irrigation needs with limited supplies of surface water. Section III (''Agriculture's Responses of Drought Conditions'') outlines the major strategies employed in 1977. Since the overall purpose of this present study is to determine if this information can help develop a long-term approach for water and energy conservation in irrigated agriculture, the present and potential conservation trategies applicable to California were identified and presented in Section IV.