Here’s the release from the Pacific Institute:

The Pacific Institute’s Municipal Deliveries of Colorado River Basin Water documents population and water delivery information and trends for 100 cities and agencies that deliver water from the Colorado River basin. Since 1990, the number of people in the United States and Mexico who use Colorado River basin water has increased by more than 10 million – but their overall per capita water use declined by an average of at least one percent per year from 1990 to 2008.

The new report provides – for the first time – real numbers on the extraordinary population growth among cities that depend on water from the basin and on changing water delivery rates by these cities. The report documents the substantial water-efficiency gains made over the past twenty years by agencies delivering water from the Colorado River basin – even by agencies and cities such as Flagstaff that already had relatively low per capita delivery rates in 1990.

Download the full report here.

Water taken from streams and rivers and pumped from the ground within the nearly quarter-million-square-mile Colorado River basin now meets some or all of the needs of almost 35 million people, including fast-growing cities within the basin such as Las Vegas and Phoenix and St. George, Utah. Some cities, especially in Arizona and Utah, have more than tripled in size since 1990. But more than 70% of the people receiving such water live outside the basin, in cities such as Cheyenne, Denver, and Albuquerque to the east and Salt Lake City, Los Angeles, San Diego, and Tijuana to the west of the basin.

From 1990 to 2008, total municipal water deliveries from the Colorado River basin increased by more than 600,000 acre-feet, at a rate much slower than population growth. In fact, the new study shows that if water deliveries had increased at the same rate as population growth, they would have grown by almost two million acre-feet – assuming that much additional water was even available for delivery.

From 1990 to 2008, per capita water delivery rates declined dramatically in Albuquerque (38%); Southern Nevada (31%); Phoenix (30%); and San Diego County (29%). Southern California agencies delivered 4% less water in 2008 than they had in 1990, despite delivering water to almost 3.6 million more people. In fact, 28 water agencies in five different states delivered less water in 2008 than they had in 1990 despite population growth in their service areas, evidence that water deliveries do not simply track population.

Municipal deliveries – which include deliveries to the residential, commercial, industrial, and institutional sectors, but do not include deliveries to agriculture, energy producers, or mining – comprise about 15% of total Colorado River use (agriculture uses more than 70%). But as the fastest-growing sector, municipal use drives demands for additional water supplies and places pressure on a river system that is over-allocated and facing a supply-demand imbalance, as well as the prospect of long-term declines in run-off due to climate change.

Municipal Deliveries of Colorado River Basin Water shows that projecting future water demands should take into account the successes achieved in cities where there are many examples of water conservation in practice that could be adopted or emulated by the less water efficient providers.

The Pacific Institute has also posted the data used for the report, available as a spreadsheet here.

Data were generally reported by the agencies themselves. Email crbwater [at] pacinst.org if you have any corrections to the data, or would like any additional information.

More coverage from Joe Hanel writing for The Durango Herald. From the article:

The Pacific Institute report, to be released today, shows cities in the Colorado River Basin saved 2 million acre-feet a year compared with their per-person consumption rates in 1990. “That’s a huge amount of water, so that’s a lot of savings for the system,” said Michael Cohen, author of the report…

Durangoans use an average of 209 gallons of water a day, above the 2008 Colorado average of 176 gallons. The Durango City Council adopted a water-efficiency plan Monday night with the goal of further reducing waste in the system…

The Colorado River serves as the main water supply in the Southwestern United States, from Denver to Los Angeles. The U.S. Bureau of Reclamation found this year that the average demand on the river has begun to exceed the average supply. Farms still consume 70 percent of the river’s water, but cities present the fastest-growing demand, the report says. The basin’s population has boomed to 33.5 million, an increase of 10 million since 1990, according to the report. But the increase in water use was far below the population increase, and some cities – including Los Angeles and Albuquerque – used less total water in 2008 than in 1990, despite growing populations.

More coverage from Gary Harmon writing for The Grand Junction Daily Sentinel. From the article:

“This is a significant achievement, demonstrating that water demand can be successfully delinked from growth,” study author Michael Cohen of the Oakland, Calif.,-based Pacific Institute wrote in its report: “Municipal Deliveries of Colorado River Basin Water.” While the notion that water can be used more efficiently is not a new one, the study illustrates there is plenty of room for improvement, said Gigi Richard, director of the Water Center at Mesa State College.

“There is the potential for leaps and bounds of water savings” through more efficient use of water, Richard said. “I think we still have a long way to go” to make maximum use of water…

Had water agencies from the Front Range of Colorado to the Pacific Coast delivered water to their customers in 2008 at the same rate they were in 1990, they would have piped about 8.5 million acre-feet into homes and businesses. Instead, the amount delivered was about 6.5 million acre-feet…

Cohen, who began his study in August, carefully avoided trying to draw policy conclusions. “I’m trying in this report to be unbiased,” he said. “I hope other people use the data and draw their own conclusions.” The study, however, “certainly raises the question” as to how much water remains in the Colorado River for appropriation, he said.

More conservation coverage here.