Economic adjustments to groundwater depletion in the high plains: Do water-saving irrigation systems save water

Abstract

A common policy prescription for conserving irrigation water is to promote more efficient or “water-saving ” irrigation technologies. We develop a risk-programing model to quantify the effect of irrigation efficiency on irrigation water use in the High Plains, taking account of irrigation timing and well capacity limits. We find that optimal irrigation does not respond monotonically to changes in efficiency, although intermediate and high-efficiency systems both result in less water use than an inefficient flood system. Key words: irrigation efficiency, irrigation timing, High Plains, Ogallala aquifer, water conservation. The High Plains is a semi-arid region encom-passing much of the Texas and Oklahoma pan-handles, eastern portions of New Mexico and Colorado, and western portions of Kansas and Nebraska. Although irrigated crop production in this region accounts directly for a small share of economic activity and employment, it is a primary pillar of the local economy. Extensive irrigation over the past several decades has generated substantial supplies of feedgrains and forages, which in turn have attracted a large number of cattle-feeding and meat pro-cessing operations to the region. Within the High Plains, the meat processing sector is cur-rently the primary driver of regional economic development and population growth. By far, the largest single source of irriga-tion water in the High Plains is the Ogal-lala aquifer. Despite its status as the largest freshwater aquifer in the world, the Ogallala recharges very slowly and its available water volume has been steadily declining over the past three decades. Recent drought and the near exhaustion of the aquifer in some areas have prompted a renewed interest in regional policies to conserve groundwater (Peterson, Marsh, and Williams)