For more than a century, irrigated agriculture has been an essential element in the economy of the West. The rivers and streams were diverted and beneficially applied to the fields almost as soon as the first settlers arrived. As a consequence, many streams throughout the arid West soon became overappropriated, with insufficient water available to all users. During dry years, as the spring runoff waned and empty streambeds appeared in the latter part of the irrigation season, many water users were left to watch their crops wither in the sun.
In the mid-twentieth century, however, relief came to those junior users who had to rely on undependable snowpack and late summer rains in order to fully water their crops. Cheap energy and improved well drilling technology developed, allowing for the exploitation of ground water to supplement the late season surface supply. In addition, the drilling of numerous wells following World War II enabled the farming of vast tracts of fertile lands which previously had no available irrigation source.
It was not long, however, before the negative implications of massive ground water use put a damper on its enthusiasts in the West. Two major categories of problems arose. First, well users drawing from ancient aquifers which received very little recharge found themselves in a mining situation wherein water tables dropped and the pumping of one well had an adverse impact on others. The second negative situation occurred in those areas where well pumping impacted streams and rivers, thus “robbing” surface water users of their rightful supply.
. . .