REGIONAL IMPACT OF URBAN WATER USE ON IRRIGATED AGRICULTURE

Linear programming and regional input-output models were applied to estimate the impacts of increased pumping costs for irrigated agriculture due to groundwater depletion principally caused by the expanding urban area of San Antonio, Texas. A biophysical simulator was use to estimate linear programming coefficients of crop yield by irrigation level and timing. The results indicated significant local (county) economic impacts from groundwater mining but insignificant regional impacts. A major improvement on irrigation efficiency would be required to offset the increased pumping costs and reduce water availability associated with increased lifts due to urban expansion