Study: Drought will cut flow from Lake Powell

Dennis Wagner | USA TODAY

PHOENIX — A federal Bureau of Reclamation study released Friday says the Colorado River's worst drought in a century will force reduced water releases from Lake Powell in Arizona that could affect agriculture, downstream business and hydroelectric power production.

Groups urging conservation warned of drastic water cutbacks and severe economic implications, while state officials and the Central Arizona Project sought to downplay the alarm.

The bureau said releases from Lake Powell in the coming year will be cut from 8.23 million acre-feet to 7.48 million acre-feet — the lowest since the lake was first filled in the 1960s. An acre-foot is roughly 325,000 gallons, or enough to supply two households for one year.

Water from Lake Powell flows through the Grand Canyon to Lake Mead, where levels are expected to drop 8 feet next year, causing reduced deliveries to farms and water banks.

"This is the worst 14-year drought period in the last 100 years," said Larry Walkoviak, the Bureau's Upper Colorado Region director.

Based on the projections, CAP officials said shortages could trigger a 20% decrease in Arizona deliveries to agriculture.

However, they emphasized that water delivery to towns and cities will not be affected, and Phoenix's Water Services Department issued an assurance to customers that there will be "no impact on the city's water supply." A municipal news release added, "Even if poor snowpack persists for the next two years and an actual shortage is declared ... Phoenix would be able to take all of the Central Arizona Project water it needs."

Protect the Flows, a coalition of businesses that rely on the Colorado River, said the forecast dramatically increases chances of an "unprecedented water crisis within the next few years."

Chuck Cullom, Colorado River project manager for the CAP, said that Lake Powell is only 45% full, the second-lowest level ever, and that Lake Mead is at 47%.

He confirmed that the forecast would trigger CAP cutbacks of 320,000 acre-feet, a 20% decrease. However, he expressed surprise at Protect the Flows' dire warnings: "That's not what the 24-month study will show. It is not Armageddon. It's what we've been planning for for decades."

Cullom said reduced generation of hydro-power is plausible, but it would occur only if the Colorado River drainage was hit with the two worst years of runoff on record.

Based on the federal projections, CAP is expecting a 9% reduction in Lake Powell releases during each of the next two years.

Sandra Fabritz Whitney, director of the Arizona Department of Water Resources and chairwoman of the Arizona Water Banking Authority, said, "While the possibility of a shortage declaration is significant, Arizona has been planning and preparing for just such a condition."

Dennis Wagner also reports for The Arizona Republic