Water level at Lake Mead could rise thanks to wet winter, report says

By Dylan Scott

Saturday, Jan. 15, 2011 | 1:55 a.m.

As long as snow continues to fall steadily in the Rocky Mountains this winter, Lake Mead should receive a much-needed injection of water, according to projections released this week by the U.S. Bureau of Reclamation.

The thirsty lake, which supplies much of the water for the Las Vegas Valley, could see its surface level rise more than two dozen feet, according to government officials.

Snow accumulation in the Colorado River Basin above Lake Powell in Utah is more than 30 percent above historical levels, the bureau estimated. If that number holds steady through the spring, Lake Powell’s depth could rise to 3,643 feet, a trigger point that would prompt the bureau to release at least an additional 3.13 million acre-feet of water into Lake Mead over the summer.

As part of the Colorado River Compact, Lake Powell annually releases 8.23 million acre-feet of water into Lake Mead. According to agency statistics, if the higher threshold were reached at Lake Powell, a total of 11.36 million acre-feet of water or more would flow into Lake Mead by September.

Andrew Munoz, spokesman for the Lake Mead National Recreation Area, said 100,000 acre-feet is equal to about 1 foot of elevation on the lake. If 3.13 million additional acre-feet of water was pumped into the lake at once, the surface level would rise more than 30 feet.

Munoz cautioned, however, that the water would be released gradually so the total change in water level would likely be less, especially when factors like evaporation were incorporated.

Still, it’s great news for Lake Mead, where water levels have dipped significantly in recent years. Since the drought struck the Colorado River Basin in 1999, Lake Mead has dropped to historic lows, dipping to 1,082 feet in October and forcing the closure of several boat launch ramps. When full, the lake should be at 1,220 feet.

Less snow has accumulated since the drought began. At this time last year, Munoz said accumulation was about 20 percent below the historical norm.

This year, he said, more storm systems have been moving through the region.

“It’s encouraging, but we’re not throwing a party yet,” Munoz said. “It’s kind of a waiting game. We’re trying to temper our optimism.”

The Bureau of Reclamation projected a 76 percent chance that Lake Powell would reach the 3,643-feet threshold by April 1, the deadline for a decision to be made.

Until then, the staff at Lake Mead will be “watching closely,” Munoz said.

If lake levels increase, Munoz said, boat launch conditions should be more stable, allowing more ramps to remain open. The National Park Service generally estimates that every 20-foot drop in water levels costs $6 million, Munoz said, because the boat launch ramps must be extended and crews are hired to do the work.

Money could be saved for the future in case Lake Mead’s level falls again, Munoz said, or utilized for other projects, such as improving the park’s facilities.

If a trend holds and the lake continues to see a larger flow from Lake Powell in the next few years, Munoz said the park would also explore reopening boat launch sites, like the one at Overton Beach, which had been closed indefinitely.