Our Water, Our Future News

A new analysis of government data released today by the Arizona PIRG Education Fund found for the first time that the West’s major river basins are getting warmer, at exactly the time of year water needs to be stored as snow to meet the region’s water needs. The report finds trends that go beyond occasional or seasonal drought, showing a steadily declining snowpack in the Mountains which could mean a shortage of water flowing into rivers and communities.

Despite the past year’s above-average snowpack, the report found that compared to the historical average, the Colorado River basin – which provides much of Arizona’s water – is facing warmer winters and smaller snow packs. Three-fourths of the water used in the West starts as snow.

According to Lela Prashad, Public Interest Advocate for the Arizona PIRG Education Fund, “Mountain snow packs are our largest reservoirs, dwarfing those people have built. They naturally delay runoff for months, until spring’s warmth releases it as snowmelt. In the future, warmer winters and smaller snow packs could make late-summer water restrictions a lot more common.”

These climate changes could have important impacts on local communities and businesses. “It is important to conserve the water that we have right now and to take steps to ensure that climate change doesn’t disrupt our future supply,” noted Ron Doba, the Utilities Director for the City of Flagstaff.

“Living in the desert, our business community is constantly aware of possible water supply and/or shortage issues. We endeavor to plan and work proactively, thereby helping to guarantee an amply supply of water in Tucson now and for years to come,” said Paula Stuht, Director of Economic Development for the Tucson Metropolitan Chamber of Commerce.

The new Clear the Air report, entitled “Less Snow, Less Water,” was written by the Rocky Mountain Climate Organization (RMCO) and is based on data from the National Oceanic and Atmospheric Association (NOAA). It looked at four major river basins in the West, including the Colorado, which provides most of Arizona’s water. The study found:

Reduced Snow pack — Government snow pack-measurement records going back to 1961 indicate that snow pack levels have been below average for 11 of 16 years in the Colorado River basin.

Increased Temperatures — In the Colorado River basin, the most recent five-year period was the hottest in the past 110 years. In the upper Colorado River basin, 2000-2004 was 2.1°F hotter than the historic average.

Winter Warming — The warming seen in the Colorado River basin has not been random throughout the year. The monthly pattern of increased temperatures between 1995 through 2004 shows that warming has been greatest in January, February, and March – a “fingerprint” of global warming. This is also when warming has the greatest potential to reduce the amount of precipitation that falls as snow.

“ Arizona and the West are inherently vulnerable to even small changes in the snow-water cycle,” said Prashad. “With a rapidly increasing population and a dwindling water supply, the threat posed by global warming to our water supply should give Arizonans ample reason to take action.”

The full report can be downloaded at www.arizonapirg.org