Effects of Colorado River water quality and supply on irrigated agriculture

A production function relating irrigated crop yield to the quality and supply of irrigation water is developed. It was found that the adverse effects of saline irrigation water can be offset by application of additional water over and above that required for plant transpiration. Results indicate that a degradation of the water supply in the Colorado River at Imperial Dam from the existing level of electroconductivity of 1.50 mmho to the projected level for the year 2000 of 2.0 mmho would cause a decline in the return to land and water of about 14% for farmers in the Imperial Valley of California. Because of the relatively elastic demand for irrigation water at the current price, any attempt to ration water through a market price mechanism would have no effect, unless water rates were about double their current levels.