States offer water plan

Nevada and the six other Colorado River states plan to send the Interior Department a landmark water supply plan today that, if approved, will put measures in place to keep Lake Mead's level steady if the drought worsens.

At the same time, the plan allows the Southern Nevada Water Authority to tap its holdings in Coyote Spring basin and, for the first time, use its rights to water from the Virgin and Muddy rivers.

Combined, those three sources account for up to 45,000 acre-feet of additional water for Nevada in Lake Mead that could be used for distribution to the Las Vegas Valley from the lake's intakes at Saddle Island.

An acre-foot is about 326,000 gallons, which is almost enough water to supply two average Las Vegas homes for one year.

If adopted by Interior Secretary Dirk Kempthorne, the water supply management plan "would represent the most comprehensive set of operating guidelines in the history of the Colorado River," officials from the Southern Nevada Water Authority and the Colorado River Commission of Nevada said in a joint statement scheduled to be released today.

The plan includes a water shortage agreement between Nevada and Arizona and puts in place a concept called "intentionally created surplus" to keep more water in Lake Mead, Lake Powell and other reservoirs on the river and allow them to recover quicker from drought.

For example, water for agriculture in Southern California can be kept or "banked" for future use in Lake Mead if crop lands are allowed to go fallow.

In an interview, Southern Nevada Water Authority Deputy General Manager Kay Brothers said Lake Mead's surface elevation will be kept in check by ensuring that enough water upstream from Lake Powell will be released so that Lake Mead's level doesn't drop below 1,025 feet elevation. The lake is currently at 1,122 feet elevation.

In return for releasing more water from Lake Powell, Nevada's annual 300,000 acre-feet allocation from the Colorado River system at Lake Mead would be reduced depending on the drought-induced shortage, but would not total less than 280,000 acre-feet.

The first allocation reduction of 13,000 acre-feet would be triggered if Lake Mead's level drops to an elevation of 1,075 feet. The amount would increase to 17,000 acre-feet at the 1,050 foot-elevation mark and bottom out at a 20,000 acre-feet reduction at 1,025 feet elevation.

"That's the worst it gets," said Southern Nevada Water Authority spokesman J.C. Davis.

He said under existing rules, the upper basin states of Wyoming, Colorado, Utah and New Mexico must deliver 8.23 million acre-feet per year to the remaining three lower basin states: Nevada, Arizona and California.

Under the proposed plan, the upper basin could deliver less water if the drought continues with less-than-average snowpack on the Rocky Mountains' western slopes.

The lower basin states would make adjustments by augmenting their supplies through intentionally created surpluses.

Brothers said a key to making that work in Southern Nevada will be building a 20-mile-long pipeline from wells in the Coyote Spring basin to Bowman Reservoir near Moapa or the Muddy River there. The Southern Nevada Water Authority holds rights to about 9,000 acre-feet of groundwater in the Coyote Spring basin.

This pipeline would be separate from one being considered by local water officials to deliver pumped groundwater to the Las Vegas Valley from White Pine and Lincoln counties in Eastern Nevada. The state engineer recently granted the authority the right to pump up to 60,000 acre-feet of groundwater from Spring Valley in White Pine County.

As a safety valve measure under the plan announced today, the Southern Nevada Water Authority will help finance construction of the proposed, Drop 2 Reservoir in Southern California's Imperial Valley, near the Mexico border.

For its financial contribution, the authority will receive a one-time water credit of 300,000 acre-feet from Lake Mead as water deliveries destined for Southern California are canceled when rains occur and the delivered water is stored in Drop 2 Reservoir.

In all, Nevada could receive another 75,000 acre-feet of water from the Colorado River system under augmentation agreements by the states. The 75,000 acre-feet would be in addition to the 45,000 acre-feet from Coyote Spring basin and the Virgin and Muddy rivers. This additional water would come from projects the seven states approve such as desalination projects or wastewater reuse projects in California and Arizona.

In the joint statement, Pat Mulroy, the authority's general manager, said the plan is "critical to helping us protect the residents of Southern Nevada because it provides us a greater level of certainty in very uncertain times."

George Caan, the commission's executive director, said the "adversity of drought has brought the states together and forced us to rethink how we manage this precious resource."

"Ironically, the level of cooperation and flexibility reflected in this plan would have been unthinkable in times of plenty," Caan said in the statement. "This represents a giant step forward in terms of our ability to balance the needs of agriculture, the environment and municipal water customers."

Brothers said the ability of the seven states to agree on the plan "was pretty tremendous."

The plan is being submitted to the Bureau of Reclamation today as part of comments by the seven states for a draft impact statement on Colorado River operations.