The white ring surrounding Lake Mead shows how far the water levels have dropped in the current drought. But heavy snowpack in the Rocky Mountains this winter is expected to send relief bringing a rise in water levels of 30 feet by year’s end at Lake Mead.

By Mike Donahue

Moapa Valley Progress

Near-record snowpack in the far reaches of the upper Colorado River will translate into an additional 2.87 million acre feet of water in Lake Mead this year. By the end of December this will raise the water level an astonishing 30 feet.

The increase in water is already underway and the lake has been climbing almost a foot every week or so. By the end of the water year on Sept. 30, Lake Mead is projected to hit 1,114.92 feet of elevation. That’s an increase of more than 19 feet just from April 30 alone when it was 1,095.76, according to Bruce Williams, Bureau of Reclamation (BOR) river operations manager.

That’s an immense amount of water in a lake that for the most part has been almost steadily falling since 2000. The bleached 100-foot “bathtub ring” around the reservoir is a stark reminder of higher waters.

On April 30 the water in the vast Lake Mead was estimated at 11.1 million acre feet. By Sept. 30, it will be about 12.87 million acre feet, an additional 1.77 million acre feet. In everyday terms, an acre foot or about a football field of water one foot deep, is 325,851 gallons — roughly the amount of water an average Moapa Valley household uses annually.

Williams attributed the steady increase in Lake Mead to this year’s astounding snowpack in the Upper Colorado River Basin. As of last Sunday (May 15) it was listed at 168 percent of average for that date.

Additionally, Williams said the water content in the snow this year is exceptional “and it’s still falling.”

“They’re forecasting another storm (Wednesday, Thursday and Friday) that could add considerably to the water in the Colorado River System,” Williams said.

The Colorado River starts as a trickling stream at the Continental Divide high in the Rocky Mountains. As it flows south the stream gradually becomes a river. It is fed and nourished by moisture – snow and rain — that has fallen in the mountains of Utah, Wyoming and Colorado generally from late October to May.

Historically each spring, as the snowpack melts and adds replenishing water to the river system, the flow becomes a torrent. Before completion of Hoover and Glen Canyon dams the raging water would often cause extensive and costly damage throughout the length of the 1,450-mile-long river.

Preventing damage and controlling the wild and unpredictable river were the primary reasons Hoover Dam was constructed in the 1930s. Electrical power generation, water storage and recreational activities were secondary benefits that have since come to the forefront.

Glen Canyon Dam, however, behind which sits the Lake Powell, was constructed in the 1950s principally to produce power and provide a constant source of water for the arid regions of the desert Southwest.

Because Lake Powell is first in line, it benefits first from the Colorado River influx. Nevertheless, it, too, has been severely impacted by the 11-year drought and as of last week was nearly 85 feet below full pool or down more than 45 percent. Like Lake Mead, however, it has slowly been filling, climbing almost a foot a day during some periods.

Lake Powell is required to release a minimum of 8.23 million acre feet of water to Lake Mead each year and the BOR last week upped that release to 12.46 million acre feet by October, the largest release since 1998, Williams said.

In addition to the Colorado, the Muddy and Virgin rivers contribute their flows to the Lake Mead water levels. Both will benefit from the extraordinary snow fall this year and as their water levels climb, so, too, will the amount they add to Lake Mead.

The spring-fed Muddy will benefit from the dense snowpack because the many underground aquifers that help support its sources are fed by the runoff. The Virgin River is expected to quadruple its flow into Lake Mead by Independence Day because of the water it will receive this spring from snowmelt.

“We’re looking at significant flooding in the state of Utah,” Williams said. “The rivers are already near flood stage all over the state and the snow really hasn’t even started to melt yet. If it stays warm during the upcoming storms and the snow really starts melting, there’s going to be some real problems there.”

The Virgin River is one of the very few western rivers whose flow is not dam-controlled. The flood danger along the river is almost totally regulated by Mother Nature, which means officials often rely on “hope and a prayer” to combat potential harm from high and relentless water.

The Las Vegas Review Journal reported last week that authorities in Mesquite are shoring up dikes and other structures along with river. Mohave County in Arizona is also working with federal officials on flood and erosion control in the Beaver Dam Wash north of Mesquite.

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