Posted: March 01, 2011
Lake Mead’s decline: Not just a Vegas problemBy Allen Best
The day we visited Lake Mead, near Las Vegas, the reservoir was at 42 percent of capacity and dropping, as it has been for most of the last 10 years. It was just before Christmas, gray and chilly. I was glad to have a winter jacket.
Vegas is a gambling town, and the house knows the odds. That's why Pat Mulroy, who heads the Southern Nevada Water Authority, surely calculated the chances before pulling the lever on a $700 million tunnel into the bowels of the reservoir. Having looked over the horizon, she doesn't like what she sees. And if she doesn't, Colorado shouldn't either.
Lake Mead began filling 75 years ago after completion of Hoover Dam, a triumph of 20th century America. The dam tamed the wild, unruly Colorado River, in one giant step allowing a more measured civilization in the uneven geography of wet and dry, high and low of the American Southwest. It enabled others: Green Mountain, Blue Mesa and Dillon in Colorado, and others outside the borders. Among the newest, and largest, is Lake Powell, located on the upstream side of the Grand Canyon from Las Vegas.
All those projects assumed plentiful water - and indeed, this year, with the Rocky Mountains laid deep in snow, there may be a big runoff. But that hasn't been the trend lately, nor is it likely to occur often in the future - hence the Big Bet by Vegas with its new tunnel. The city gets 80 percent of its water from Lake Mead using two tunnels. Now it has sunk a shaft for a third tunnel. This new tunnel will dive deeper, under the reservoir, emerging at a level slightly above the original course of the Colorado River, in what is called the dead pool. A dead pool exists when a dam has so little water that there is no way to release it. If things go badly, that will be the case at Lake Mead in maybe 15 years.
Drought in the Colorado River Basin has prevailed since 1999, interrupted by only a few average or above-average years. That decline has left a chalky, bathtub ring around Lake Mead, a visual reminder of what once was. This year's flows might eclipse a portion of the ring, but only temporarily. Several dozen climate models show unusual consensus in predicting markedly higher temperatures for the Colorado River Basin. Precipitation being equal, this greater heat will result in a 10 percent to 20 percent decline in river flows by mid-century. Some even question whether both Mead and Powell will be justified. Evaporation losses would be less with just one.
On The Strip, water people from Denver to Los Angeles were gathered for a meeting of the Colorado River Water Users Association in what I call the Hall of One-Breasted Women because of all the knockoff statues of Roman women. Others call it Caesars Palace. Interior Secretary Ken Salazar announced a pact honoring water claims of the Navajo and Hopi nations, and water needs of power plants was discussed. The most provocative comments came from Douglas Kenney, a law professor at the University of Colorado.
Kenney contends that, obscured by the drought, a giant threshold was quietly crossed during the last decade in the Colorado River Basin. Crossing that threshold has enormous implications for the 24 million to 30 million people who depend on Colorado River water, including most of Colorado's 5 million people. Demand, he said, has outstripped supply. That's why Mead has continued to decline even in above-average years. "I think we have a broken water budget, and if you look at the projections, it's only going to get worse," Kenney said to the 500 or so people.
This isn't just a Vegas problem, Kenney said, nor even a lower-basin problem. Colorado, the source of half the annual flows of the river, and the other upper-basin states of Wyoming, Utah and New Mexico, should care. Despite lower flows, we must still deliver water as if there had been no change brought about because of increased heat. Modeling by the U.S. Bureau of Reclamation finds it virtually certain that such a so-called compact call will happen by 2026.
That requirement is found in the 1922 Colorado River Compact, the core document for a broader set of laws of almost biblical length. Woe to those who challenge its divine inspiration. Sen. John McCain, when running for president in 2008, got flogged endlessly by editorial writers after suggesting, in an interview with the Pueblo Chieftain, that modifications should be considered. With an eye for the easy quote, Salazar said any modification of the Colorado River Compact would occur over his dead body.
It's easy to be contemptuous of Las Vegas. A metropolitan area in a place that gets just 4 inches of annual precipitation, it has surpassed Manhattan in population based on an economy of licentiousness. Stay in your britches! It's also easy in Aspen, or Denver, to wag a finger at Douglas County, the area of sprawling bedroom communities south of Denver that leads Colorado in population growth and arguably wealth. It can be considered Colorado's equivalent to Las Vegas, except that Douglas County's boom was premised on well water that a long time ago people realized wouldn't last very long. But Colorado won't let Douglas County wither. It's not realistic. Like it or not, we're more or less family.
In December, after visiting the shaft for the new tunnel into Lake Mead, we drove along what had once been the reservoir's edge. Stopping, we walked out onto the wooden platform of a fishing pier. But instead of water, or fish, there was thin air. The water is now a half-mile away.
Beyond was a boat ramp, its concrete segments a now-deserted history of the last 15 years: first one new segment then another as the National Park Service tried to provide continued access to the receding reservoir. Finally, they moved the marina to an entirely different location. The reservoir hadn't been that empty since 1938, soon after Hoover Dam was completed.