Lake Mead’s good news equals even higher water levels

The good news for Lake Mead now has some numbers attached to it.

Las Vegas' main source of drinking water is expected to swell with almost 12.5 million acre-feet by October, according to new projections released Wednesday by the U.S. Bureau of Reclamation.

That's an increase of 1 million acre-feet from just one month ago, and it comes as a result of near-record snow accumulations in the mountains that feed the Colorado River and its main tributaries.

The additional water now set for release upstream from Lake Powell is expected to raise the level of Lake Mead by 32 feet by the end of February.

The valley draws about 90 percent of its drinking water supply from Lake Mead. One acre-foot of water is enough to supply two average homes for one year.

Under agreements dating to 1922, Lake Powell is required to send a minimum of 8.23 million acre-feet of water downstream to Lake Mead each year.

Last month, bureau officials set this year's release at 11.56 million acre-feet. On Wednesday, that figure was increased to 12.46 million acre-feet, by far the largest release since 1998.

Bureau officials will continue to review river conditions on a monthly basis to see whether more adjustments are needed.

The extra water for Lake Mead is expected to delay for several years an unprecedented shortage declaration that would require Nevada and Arizona to cut their Colorado River use.

This year's release will be so great that bureau officials will need a few extra weeks to deliver it all. Otherwise they would have to bypass the generators at Lake Powell's Glen Canyon Dam and give up an opportunity to generate electricity with some of the water.

The expected rise in Lake Mead is welcome news for National Park Service personnel and private marina operators at the nation's largest man-made reservoir. Over the past decade, they have spent millions moving docks, extending roads and utility lines to reach the receding shoreline.

The surface of Lake Mead now sits at about 1,096 feet above sea level, 115 feet lower than it was in 2000. The reservoir sank to an all-time low in November before rebounding over the past five months.

Since drought took hold 11 years ago, the overdrawn Colorado has flowed at just 69 percent of its 100-year average.

This year, forecasters expect it to flow at 145 percent of average.