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July 29, 2014

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ENVIRONMENT:

The nation’s most endangered waterway is in our backyard

Image

New York Times / Jim Wilson

A view of Hoover Dam and Lake Mead shows canyon walls ringed with white mineral deposits indicating the drop in water levels near Boulder City, Nev., Dec. 18, 2013.

Five lousy percent never looked so good.

But with the West gripped by a drought so severe it’s spurred talk of fallowed farms and emergency water restrictions in recent months, it’s practically worth celebrating that the snowpack that feeds the Colorado River is expected to produce 5 percent more water than average this year.

“It’s not going to do much for the recovery,” Southern Nevada Water Authority spokesman J.C. Davis said. “But at least it’s not going to do anything to exacerbate the deficit.”

That deficit has been more than 10 years in the making, fueled by recent winters when the snowpack has been as much as 27 percent lower than average. During that time, the water level at Lake Mead has fallen by 108 feet from its peak in 1998 to a current level of 1,103 feet, leaving behind the layer of mineral deposits that Las Vegans know as the bathtub ring.

Meanwhile, the Colorado River is being taxed more than ever. American Rivers, a nonprofit dedicated to the conservation of rivers and waterways across the U.S., ranked the Colorado No. 1 last year on its list of most endangered rivers.

“This year’s America’s Most Endangered Rivers report underscores the problems that arise for communities and the environment when we drain too much water out of rivers,” American Rivers’ President Bob Irvin said in announcing the rankings. “The Colorado River ... is so over-tapped that it dries up to a trickle before reaching the sea.”

So, how much more water loss can Las Vegas take, especially given that the water in Lake Mead is shared with millions of others in the drought region?

The short answer is that Las Vegas will have water for a long time and that contingency plans are in place even in the unlikely event that Lake Mead becomes all bathtub ring and no water.

But the more complicated answer is that, while Las Vegas will still have water, residents will have to pay for the drought in more ways than one.

A look at things to come

The Lake Mead water level is projected to continue dropping over the next 12 months despite the wet winter in Colorado, mainly due to a second straight year of cuts in the reservoir’s annual allocation of water from Lake Powell. The reduced downstream discharge means 750,000 fewer acre-feet of water — about a three-year supply for Las Vegas — won’t reach Lake Mead, which could drop its surface elevation by another 35 feet over the next year and trigger the first in a series of federal shortage declarations that will limit the amount of water being drawn from the lake.

A declaration likely wouldn’t have much effect on Las Vegas — you’ll still be able to wash your car and water your plants — but it could be just the beginning.

That’s because there’s uncertainty about what is happening with the weather. Climatologists and hydrologists are unsure whether the current drought is similar to arid stretches lasting 10 to 15 years that occur once or twice a century throughout history, most recently in the 1950s, or whether changing climate patterns have created a new, drier normal for the western United States.

If the drought persists for several more years, and especially if it worsens, problems caused by the falling Lake Mead water level would be severely exacerbated.

Will Las Vegas go dry, or will the 2 million local residents who rely on the lake for 90 percent of their drinking water even see any restrictions on water usage? Not anytime soon, thanks to the federal declarations and a group of contingency plans in Nevada, including a new water intake pipe deep in the lake and a controversial proposal to pipe water in from rural Northern Nevada. But those and other contingencies are expensive, meaning local residents could end up paying a lot more for what comes out of their faucets.

The Southern Nevada Water Authority has embarked on an $817 million project to build a third straw at Lake Mead to continue pumping water into the valley as the surface level declines.

The oft-delayed project isn’t scheduled to be finished until next year, forcing the authority to pursue emergency alteration of the first straw, costing $12 million to keep it online in the interim. The straw as originally designed would stop pumping efficiently at a lake level of about 1,065 feet, but the emergency fix will allow it to keep working to a level of 1,050 feet.

Fifteen feet may not sound like much, but the project could buy several years of time. The lake level has generally been dropping 5 to 20 feet per year since the late 1990s, but it got a 33-foot boost in 2011-12 thanks to enormous snowfall in the Rockies. Today, the level is about 20 feet over the all-time low of 1,082 feet in 2010.

As for the second intake, it’s safe until the lake reaches 1,000 feet. But if and when it goes offline, it would require alterations costing several hundred million dollars.

Other effects

Five new turbines are being installed at the Hoover Dam at a cost of $12 million to keep generating electricity at lower lake levels. The new turbines will become less and less efficient with every foot the lake drops after 1,050 feet and would eventually stop functioning at 950 feet of lake elevation, a remote possibility that is still years away, barring an intensification of the drought. Trouble at the dam could eventually mean higher electric bills for the millions of consumers, mostly in California, who use its power.

Potential political chaos looms once the lake dips below 1,025 feet, a prospect that is still at least a few years off but grows closer with every dry winter. The seven states that rely on the Colorado River have agreed to take increasingly less water from the system when Lake Mead drops below 1,075 feet, which could happen as soon as May 2015. Further restrictions are set to go into effect when the level reaches 1,050, and yet another set kicks in at 1,025 feet.

Southern Nevada would see its 300,000 acre-feet allocation per year, the smallest of any state, slashed by a maximum of about 7 percent cumulatively if all three restrictions took place. To put that in some perspective, an acre-foot is equal to about 325,000 gallons of water, which is the amount used by two average homes in one year. For an idea of how tiny Nevada’s allocation is, consider that the seven states combined draw about 15 million acre-feet of water from the river annually.

But then what?

No rules have been set for once Lake Mead’s elevation drops below 1,025 feet, setting up a potential political showdown between states, cities and farms over access to the dwindling supply of water.

The chaos could lead to less water for agriculture, fallowed farms and eventually higher food prices. It could also require the construction of expensive and novel technologies, like massive desalinators that would process ocean water into a drinkable form.

Such a scenario could be the final trigger for the water authority’s controversial plan to begin piping groundwater from rural Nevada to satiate Las Vegas’ continued thirst, a move that would see ratepayers footing the bill for more than $3.2 billion of new construction.

The effects go well beyond the price tag, too. The authority’s water grab has met fierce resistance from landowners, environmentalists, ranchers, Native American tribes and others, leading to a series of legal battles. Two federal lawsuits filed in February challenged the authority’s right to build the pipeline over more than 250 miles of public land. A December decision by a District Court judge restricting the project’s water rights is being appealed to state Supreme Court.

The pipeline’s opponents say funneling the region’s precious water supply south threatens to hurt agricultural production, wreck the environment, cost jobs and chase people out of the region. But many Southern Nevadans argue that it’s in the state’s best interest to send water southward to drive Las Vegas, the state’s economic engine. It’s not just a matter of keeping fountains running and pools full for tourists.

In a state where northern and southern residents have long been at odds over allocation of state funding — with many Southern Nevadans believing it’s unfairly spent in the north — the pipeline could deepen the division.

For now, though, scientists and water officials will anxiously watch over the next two months to see how much difference the above-average snowpack will make. Some will be lost to evaporation or sucked up by vegetation as it makes its way downstream to the dozens of cities that rely on the river for their water supply.

But in a parched part of the world where there’s no relief in sight, that 5 percent is a godsend.

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