Without dramatic and wide-ranging action, population growth and climate change will overwhelm the Colorado River within 50 years.
That was the warning from federal officials and water managers Wednesday as the U.S. Bureau of Reclamation released a first-of-its-kind forecast for the West’s most heavily regulated and relied upon river system.
The Colorado River Basin Water Supply and Demand Study projects a 9 percent decline in the river’s flow even as the number of people who depend on its water could nearly double, to as much as 76.5 million, by 2060.
“This study should really serve as a call to action,” said Interior Secretary Ken Salazar during a telephone conference call to announce the release of the analysis.
The study was compiled over three years by a team of federal officials and representatives from the seven Western states that share the river.
Southern Nevada Water Authority chief Pat Mulroy said she is most troubled by the study’s projections for climate change, which could bring more frequent and protracted droughts to the Colorado. Those who share the river can plan for the demands of a growing population, but mood swings of Mother Nature are another matter, she said.
“It underscores the need to start having the more difficult discussions … right now,” she said of the study. “We can’t wait.”
The Las Vegas Valley gets 90 percent of its drinking water from the Colorado River by way of Lake Mead. The key issue for Nevada will be protecting water levels in the reservoir, Mulroy said. “If Lake Mead isn’t healthy, Southern Nevada is in trouble.”
The study does not advocate solutions, but it does list roughly 150 options for addressing what Salazar called the river’s “troubling trajectory.”
Those options include everything from increased water conservation by farms and cities to cutting down thirsty, non-native tamarisk plants along the river. The study also sees promise in seeding clouds above the Rocky Mountains and building desalination plants along the shores of California and Mexico.
Salazar said there is no single solution.
“We are going to need to come at the problem from every direction,” he said.
Even so, he and others largely dismissed some of the study’s flashier and far more expensive ideas, such as towing icebergs from the Arctic, shipping fresh water from Alaska or diverting flows from the Missouri and other distant rivers.
Salazar said such options are not technically or politically feasible.
Bureau of Reclamation Commissioner Michael Connor said his agency has no plan to pursue a pipeline to the Colorado from the upper Missouri River though the idea did warrant additional consideration in the basin study.
Few water experts or policymakers needed a study to tell them that demand would eclipse supply on the river one day. The Colorado has faced a serious math problem since its waters were first divvied up 90 years ago.
Under the so-called law of the river, the nation of Mexico and the states of Nevada, Arizona, California, Colorado, New Mexico, Utah and Wyoming share almost 16.5 million acre-feet a year. Over the past century, however, the Colorado’s average annual flow was more like 15 million acre-feet. In the past decade, that average sank to about 12 million acre-feet. One acre-foot is enough to supply two Las Vegas homes for a year.
The shortfall projected by the study probably would have arrived already were it not for the fact that Colorado, Utah and Wyoming have not yet found a way to use all the water they are allowed to take from the river.
What the study does is quantify the crisis the basin now faces, former Southern Nevada Water Authority Deputy General Manager Kay Brothers said.
She said this marks the first time the Bureau of Reclamation has made long-range projections for the river using global climate change models.
The climate projections were combined with population growth estimates to assess the condition of the river in 50 years. The result was alarming: Demand would outstrip supply by an average of 3.2 million acre-feet a year, or roughly 10 times the Las Vegas Valley’s annual water consumption.
“It shows how dire it can be,” Brothers said. “Because of the hydrology, we’re going to be facing many more shortages.”
Brothers retired from the water authority in 2009 but stayed on as a consultant for the basin study and other issues.
When Salazar, Connor and Assistant Secretary for Water and Science Anne Castle unveiled the study Wednesday, Brothers was the sole state representative on hand for the teleconference with reporters. She said it will take a basinwide effort to bring the shrinking river into balance in the future.
“I think all of us have to take action,” she said. “The study gives us the tools really to do integrated water management for the entire Colorado River basin.”
Mulroy is hopeful that cooperative solutions can be found in time to avert disaster. After all, she said, those who share the river have already “shown great resilience” in the face of the record 12-year drought that still grips the Colorado.
Some of those difficult discussions Mulroy talked about could get their start in Las Vegas this week, as the annual meeting of the Colorado River Water Users Association continues at Caesars Palace.
Brothers will take part in a panel discussion on the basin study this morning. Salazar is scheduled to address the conference Friday morning.
Contact reporter Henry Brean at firstname.lastname@example.org or 702-383-0350.Colorado River Study