While seven states, including Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming, lay claim to water rights from the Colorado River and its tributaries, Salazar says the problem is complicated by new water agreements with Mexico that give them certain water rights to the Lower Colorado River and also provide water storage capabilities on U.S. soil, specifically Lake Mead.

Officials fear the Colorado River, the main water supply for a region larger than France, won't be able to meet demands of a regional population now about 40 million and growing over the next 50 years.

During the conference a number of advocacy groups addressed the study and Salazar’s report. The Family Farm Alliance pointed to the implications for food production in the study that estimated that irrigated acreage in the Colorado River basin will decrease by 2060.

"Policy makers and Colorado River stakeholders must understand the critical implications of taking 6 percent to 15 percent of existing irrigated agriculture out of production," alliance President Patrick O'Toole told the group.

But not all advocacy groups agreed with the results of the study. Molly Mugglestone, director of the advocacy group Protect the Flows, said she believes many states across the region “cooked the books” to show higher demand for water consumption to set up a federal bailout on expensive water projects.

But Kay Brothers, a former Southern Nevada Water Authority executive in Las Vegas who co-managed the study, warned the future water shortage projected by the study was “very real.”

"We have to begin now starting to put measures in place to meet the imbalance and prepare for a drier future," she said.