Rising demand and falling supply have water managers in the arid West projecting that the Colorado River won't be able to meet the demands over the next 50 years of a population of 40 million people and growing.
Interior Secretary Ken Salazar on Wednesday issued what he termed "a call to action" along with a three-year study of the river, its flows and its ability to meet the future needs of city-dwellers, Native Americans, businesses, ranchers and farmers in seven Western states.
The study found the population in the West could double, while today's drought-stricken Colorado River is expected to only recover about 85 percent of its historic flows.
The report dismisses some proposals, such as towing icebergs from Alaska, as impractical. But Salazar says there is "no one solution" to the challenge.
U.S. Senators John McCain and Jon Kyl released the following statement on the study:
"We applaud the Department of the Interior for sounding the alarm about the serious challenges that lie ahead for the states in the Colorado River Basin. While this study is a helpful wake-up call about forecasted water imbalances, we believe the Department of the Interior now needs to focus on analyzing practical and cost-effective solutions.
"Future studies should further examine whether there are federal regulatory hurdles impairing water and energy users from managing their water supplies in the most efficient and economically-sensible ways. An emphasis should also be made to understand how future agriculture and energy production can keep pace as water supplies tighten.
"Likewise, we encourage the Department of the Interior to only pursue practical solutions that respect the careful compromises and agreements that form the foundation of Arizona's robust water-management system.
"Proceeding with such a measured approach to these issues is vital to the economies of Arizona and all Sun Belt states."
Copyright 2012 CBS 5 (Meredith Corporation). All rights reserved. The Associated Press contributed to this report.