Dwindling Colorado River Forces First-Ever Cuts in Lake Powell Water Releases

More than a dozen years of drought have begun to extract a heavy toll from water supplies in the West, where a report released last week forecast dramatic cuts next year in releases between the two main reservoirs on the Colorado River, the primary source of water for tens of millions of people across seven western states.

After studying the problems facing the river for the past two years, the U.S. Bureau of Reclamation – the agency charged with managing water in the West – announced Friday that it would cut the amount of water released next year by Lake Powell in Arizona by 750,000 acre-feet, enough to supply about 1.5 million homes.

It marks the first reduction in water flows since the mid 1960s, when the lake was created by the construction of Glen Canyon Dam. "This is the worst 14-year drought period in the last hundred years," said Larry Wolkoviak, director of the bureau's Upper Colorado Region.

The move could trigger an "unprecedented water crisis within the next few years," the business coalition group Protect the Flows told USA Today, as reductions could have major ramifications for farmers and businesses downstream that depend on those flows, as well as on hydroelectric power generation.

"The river is already severely endangered due to way too many dams and diversions," Gary Wockner of SavetheColorado.org told National Geographic, noting the impact the reduced flows also would have on fish and wildlife throughout the Grand Canyon. "The impact on the health of the Colorado River is unsustainable."

It's difficult to overstate how important the Colorado River is to the West. From Lake Powell along the Arizona-Utah border, the river flows more than 300 miles through the Grand Canyon to Lake Mead in Nevada, supplying drinking water to more than 36 million people in Arizona, California, Colorado, New Mexico, Nevada, Wyoming and Utah.

The river also supplies water to 22 native American tribes, 11 national parks, 7 national wildlife refuges, and 4 million acres of farmland, ThinkProgress reports.

At Lake Mead, water levels will lower by 8 feet as a result of the reduction, after the lake already has dropped by about 100 feet since the current drought began in 2000, the Wall Street Journal notes. That would bring water levels there – now about 1,105 feet – within striking range of 1,075 feet, considered the threshold for the U.S. Department of the Interior to declare a water shortage.

Lake Mead

Today, Lake Powell is only about 45 percent of its full capacity while Lake Mead stands at 47 percent full, according to Chuck Collum of the Central Arizona Project (CAP), which delivers water from the Colorado River to central and southern Arizona.

He told USA Today that the forecast would mean CAP would see its water releases reduced by about 320,000 acre-feet, or a cut of about 20 percent. CAP says this will have no impact on the cities and Native American tribes it serves, however, because the reduction would impact largely underground storage and non-Indian agriculture.

For Las Vegas, which draws most of its water from Lake Mead and grew by more than 6,000 people a month in the 2000s, the extremely dry conditions of the past decade already have prompted a raft of water restrictions and conservation measures -- including banning grass front lawns in new home developments.

But the city isn't counting on conservation alone. If the conditions of the past several years continue indefinitely, by 2015 water levels at Lake Mead could drop below one of Las Vegas's two intakes there, imperiling the city's water supply. Today, its water authority is scrambling to build a third intake to allow it to draw water at levels below 1,000 feet -- an insurance policy if the lake's levels drop low enough to put its first intake out of service.

(MORE: 20 Cities That Could Run Out of Water)

"It's essentially a race for us," Scott Huntley of the Southern Nevada Water Authority told National Geographic, because the lake likely "is going to drop more precipitously than seen in the past."

At their root, the potential water shortages both lakes face is the result of what has happened to theColorado River over the past decade. Long-running drought across the Southwest has starved the river to its current low flows, and climate change is expected to reduce them by 5 to 20 percent over the next 40 years, University of Colorado geoscientist Brad Udall told Smithsonian Magazine.

Its impacts will be felt at each stage of the river's development: less snowfall in the Rocky Mountains will mean less water enters the river at its start, while hotter air temperatures and drier weather will mean longer droughts and more water lost to evaporation. More

 

The least sustainable city: Phoenix as a harbinger for our hot future

Of course, it’s an easy city to pick on. The nation’s 13th largest metropolitan area (nudging out Detroit) crams 4.3 million people into a low bowl in a hot desert, where horrific heat waves and windstorms visit it regularly. It snuggles next to the nation’s largest nuclear plant and, having exhausted local sources, it depends on an improbable infrastructure to suck water from the distant (and dwindling) Colorado River.

In Phoenix, you don’t ask: What could go wrong? You ask: What couldn’t?

And that’s the point, really. Phoenix’s multiple vulnerabilities, which are plenty daunting taken one by one, have the capacity to magnify one another, like compounding illnesses. In this regard, it’s a quintessentially modern city, a pyramid of complexities requiring large energy inputs to keep the whole apparatus humming. The urban disasters of our time — New Orleans hit by Katrina, New York City swamped by Sandy — may arise from single storms, but the damage they do is the result of a chain reaction of failures — grids going down, levees failing, backup systems not backing up. As you might expect, academics have come up with a name for such breakdowns:infrastructure failure interdependencies. You wouldn’t want to use it in a poem, but it does catch an emerging theme of our time.

Phoenix’s pyramid of complexities looks shakier than most because it stands squarely in the crosshairs of climate change. The area, like much of the rest of the American Southwest, is already hot and dry; it’s getting ever hotter and drier, and is increasingly battered by powerful storms. Sandy and Katrina previewed how coastal cities can expect to fare as seas rise and storms strengthen. Phoenix pulls back the curtain on the future of inland empires. If you want a taste of the brutal new climate to come, the place to look is where that climate is already harsh, and growing more so — the aptly named Valley of the Sun.

In Phoenix, it’s the convergence of heat, drought, and violent winds, interacting and amplifying each other, that you worry about. Generally speaking, in contemporary society, nothing that matters happens for just one reason, and in Phoenix there are all too many “reasons” primed to collaborate and produce big problems, with climate change foremost among them, juicing up the heat, the drought, and the wind to ever greater extremes, like so many sluggers on steroids. Notably, each of these nemeses, in its own way, has the potential to undermine the sine qua non of modern urban life, the electrical grid, which in Phoenix merits special attention.

If, in summer, the grid there fails on a large scale and for a significant period of time, the fallout will make the consequences of Superstorm Sandy look mild. Sure, people will hunt madly for power outlets to charge their cellphones and struggle to keep their milk fresh, but communications and food refrigeration will not top their list of priorities. Phoenix is an air-conditioned city. If the power goes out, people fry.

In the summer of 2003, a heat wave swept Europe and killed 70,000 people. The temperature in London touched 100 degrees F for the first time since records had been kept, and in portions of France the mercury climbed as high as 104 degrees F. Those temperatures, however, are child’s play in Phoenix, where readings commonly exceed100 degrees F for more than 100 days a year. In 2011, the city set a new record for days over 110 degrees F: There were 33 of them, more than a month of spectacularly superheated days ushering in a new era.

In flight from the sun

It goes without saying that Phoenix’s desert setting is hot by nature, but we’ve made it hotter. The city is a masonry world, with asphalt and concrete everywhere. The hard, heavy materials of its buildings and roads absorb heat efficiently and give it back more slowly than the naked land. In a sense, the whole city is really a thermal battery, soaking up energy by day and releasing it at night. The result is an “urban heat island,” which, in turn, prevents the cool of the desert night from providing much relief.

Sixty years ago, when Phoenix was just embarking on its career of manic growth, nighttime lows never crept above 90 degrees F. Today such temperatures are commonplace, and the vigil has begun for the first night that doesn’t dip below 100 degrees F. Studies indicate that Phoenix’s urban-heat-island effect may boost nighttime temperatures [PDF] by as much as 10 degrees F. It’s as though the city has doubled down on climate change, finding a way to magnify its most unwanted effects even before it hits the rest of us full blast.

Predictably, the poor suffer most from the heat. They live in the hottest neighborhoods with the least greenery to mitigate the heat-island effect, and they possess the fewest resources for combating high temperatures. For most Phoenicians, however, none of this is more than an inconvenience as long as the AC keeps humming and the utility bill gets paid. When the heat intensifies, they learn to scurry from building to car and into the next building, essentially holding their breath. In those cars, the second thing they touch after the ignition is the fan control for the AC. The steering wheel comes later.

In the blazing brilliance of July and August, you venture out undefended to walk or run only in the half-light of dawn or dusk. The idea for residents of the Valley of the Sun is to learn to dodge the heat, not challenge it.

Heat, however, is a tricky adversary. It stresses everything, including electrical equipment. Transformers, when they get too hot, can fail. Likewise, thermoelectric generating stations, whether fired by coal, gas, or neutrons, become less efficient [PDF] as the mercury soars. And the great hydroelectric dams of the Colorado River, including Glen Canyon, which serves greater Phoenix, won’t be able to supply the “peaking power” they do now if the reservoirs behind them are fatally shrunken by drought, as multiple studies forecast they will be. Much of this can be mitigated with upgraded equipment, smart grid technologies, and redundant systems. But then along comes thehaboob.

A haboob is a dust/sand/windstorm, usually caused by the collapse of a thunderstorm cell. The plunging air hits the ground and roils outward, picking up debris across the open desert. As the Arabic name suggests, such storms are native to arid regions, but — although Phoenix is no stranger to storm-driven dust — the term haboob has only lately entered the local lexicon. It seems to have been imported to describe a new class of storms, spectacular in their vehemence, which bring visibility to zero and life to a standstill. They sandblast cars, close the airport, and occasionally cause the lights — and AC — to go out. Not to worry, say the two major utilities serving the Phoenix metroplex, Arizona Public Service and the Salt River Project. And the outages have indeed been brief. So far.

Before Katrina hit, the Army Corps of Engineers was similarly reassuring to the people of New Orleans. And until Superstorm Sandy landed, almost no one worried about storm surges filling the subway tunnels of New York.

Every system, like every city, has its vulnerabilities. Climate change, in almost every instance, will worsen them. The beefed-up, juiced-up, greenhouse-gassed, overheated weather of the future will give ushaboobs of a sort we can’t yet imagine, packed with ever greater amounts of energy. In all likelihood, the emergence of such storms as a feature of Phoenix life results from an overheating environment, abetted by the loose sand and dust of abandoned farmland (which dried up when water was diverted to the city’s growing subdivisions).

Water, water, everywhere (but not for long)

In dystopic portraits of Phoenix’s unsustainable future, water — or rather the lack of it — is usually painted as the agent of collapse. Indeed, the metropolitan area, a jumble of jurisdictions that includes Scottsdale, Glendale, Tempe, Mesa, Sun City, Chandler, and 15 other municipalities, long ago made full use of such local rivers as the Salt, Verde, and Gila. Next, people sank wells and mined enough groundwater to lower the water table by 400 feet.

Sometimes the land sank, too. Near some wells it subsided by 10 feet or more. All along, everyone knew that the furious extraction of groundwater couldn’t last, so they fixed their hopes on a new bonanza called the Central Arizona Project (CAP), a river-sized, open-air canal supported by an elaborate array of pumps, siphons, and tunnels that would bring Colorado River water across the breadth of Arizona to Phoenix and Tucson.

The CAP came on line in the early 1990s and today is the engine of Arizona’s growth. Unfortunately, in order to win authorization and funding to build it, state officials had to make a bargain with the devil, which in this case turned out to be California. Arizona’s delegation in the House of Representatives was tiny, California’s was huge, and its representatives jealously protected their longstanding stranglehold on the Colorado River. The concession California forced on Arizona was simple: It had to agree that its CAP water rights would take second place to California’s claims. More