How to understand water and the West? A good starting point is Marc Reisner's "Cadillac Desert: The American West and its Disappearing Water," published in 1986 and updated in 1993.
Reisner examines how the West changed from "the great American Desert" to a land developer's Promised Land, all courtesy of the Bureau of Reclamation and the U.S. Army Corps of Engineers.
Reisner notes how explorer John Wesley Powell believed the arid West to be unsuitable for agriculture, except for 2 percent of the land with water. Powell's position was vigorously fought by the railroads, eager to sell land to pioneers, and equally eager to haul manufactured goods and harvested crops.
Reisner reveals how engineer William Mulholland transformed a sleepy town in southern California (Los Angeles) into a booming city of millions -- he built a giant aqueduct that sucked dry the lush farming community of Owens Valley.
Although the Virgin River in Zion National Park is undammed, neighboring rivers in the Southwest have been dammed and provide water and electric power from southern California to Las Vegas and on to Phoenix.
The book reveals how dams built on the Columbia and Snake rivers generated so much hydroelectric power, that the Northwest boomed with aluminum plants and thus aircraft plants -- the Arsenal for Democracy that out-produced the Axis during World War II. Yet those dams have also imperiled the iconic salmon runs.
A four-part television documentary based on the revised book was produced by PBS in 1996. The parts are entitled Mulholland's Dream, An American Nile, The Mercy of Nature, and The Last Oasis. (The last part explored how an over-reliance on irrigation results in salinity problems world-wide, that initially damage crops but ultimately sterilize the soil itself.)