ABSTRACT
The Tulare Basin in the San Joaquin Valley of California is characterized by extraordinarily high basin-wide efficiency of water use, an estimated 96 percent, largely because about 91 percent of the excess applied water is reused. The estimated irrigation efficiency at the individual farm level in the Basin ranges from about 60 percent to about 80 percent, and is higher than that prevailing in many irrigated areas of the Southwest, which range from 50-70 percent for the lower valleys arid 40-65 percent for intermediate valleys. The criteria for the initial selection included age of district, type of district, sources of surface water supply, groundwater use, farm sizes, scheduling system, water rights status, capital investment, soils, type of distribution system, salt conditions, and crops. The respondents were asked to identify factors underlying irrigation efficiency and to describe conditions characterizing various water districts in the Basin, including those initially selected as possible target areas for field interviewing.
