This report examines the changes that irrigators are likely to make as the cost of water rises due to increasing pumping lift and decreasing well yields in areas with ground water miningA A decline in ground water supplies exerts pressure on irrigators to adjust irrigation systems and production practices in order to increase the efficiency of irrigation water use. The adjustment strategies of irrigators are expected to respond to changing water costs and supply conditions. In the early stages of ground water decline, new wells, improved pumps, water conservation practices, and improved irrigation systems are used to maintain the availability of water in the short run and to conserve water. The crop mix is altered as water becomes increasingly costly to pump, and may ultimately revert to rain-fed or dryland farming.