Water wise

In the middle of a drought, in the middle of the desert … where do we stand?

Photo: Beverly Poppe

The foreclosure crisis. The shaky national economy. The shaky local economy. The state budget crisis. The steady climb of gas above $4 a gallon—great in a town built for driving. Hot enough for you this year? Obviously, we’ve got a lot on our minds as is, in this calm before (we hope) the next storm of explosive Las Vegas growth. But let’s not forget that the fate of Las Vegas is dependent on water. And water has made the news a lot in 2008.

Drought conditions on the Colorado River continue. The Southern Nevada Water Authority is busy trying to claim water rights in eastern Nevada to construct a huge pipeline. Lake Mead hasn’t been this low since the 1960s; a study earlier this year by the Scripps Institution of Oceanography in San Diego predicts a 50 percent chance the lake will dry up within 15 years.

In 2008, the Valley is expected to use 565,000 acre-feet of water. An acre-foot is equal to 325,851 gallons, enough water for a family of four for a year. In 2035, we’re expected to need 985,000 acre-feet per year to quench the thirst of a Valley that may be home to close to 4 million people; by mid-century we may need well more than a million.

What gets lost in the headlines is a simple assessment of where we stand. We have enough today. Tomorrow may be another story. Currently, some 86 percent of our water comes from the Colorado River; another 10 percent comes from groundwater in the Valley; the rest comes from recycled water.

With summer in full swing, now’s as good a time as any to consider the ways we use water. Where does it all come from? How much does the average Las Vegan use? What happens if we keep growing? Because, downturn or not, growth will return to the Valley.

“Historically the river was established to support agriculture,” says Launce Rake of the Progressive Leadership Alliance of Nevada, which opposes the SNWA’s plans to build its pipeline. “Nobody considered the Southwest would be home to 30 million people.”


In water, who matters? (Las Vegas Weekly, 7/17/08)
For Want of Water (Las Vegas Sun, 2008)
Lake Mead could be dry by 2021 (Scripps Oceanography News, 2/12/2008)
U.S. Bureau of Reclamation

Let’s start with Lake Mead. Named after former Bureau of Reclamation commissioner Elwood Mead, the lake was first filled in 1941 and along with Lake Powell anchors a reservoir system capable of storing 60 million acre-feet of water. When full, Mead itself stretches across 228 square miles and holds 25.8 million acre-feet. Right now, though, the lake contains only 11.9 million acre-feet, about 46 percent of its capacity.

This we know just by looking at the bathtub ring around the lake. The lake is considered operationally full when it reaches an elevation of 1,219.6 feet. The last time we were close to that elevation was in 1999, says Bob Walsh of the federal Bureau of Reclamation, when the lake was at around 1,216 feet. Currently it’s at 1,104 feet.

According to Reclamation, which manages the entire Colorado River system, over the last 102 years—the time the bureau has kept records—the average annual inflow of the river has been around 15 million acre-feet. (This figure, however, has swung from as low as 5 million acre-feet a year to as high as 24 million.) This is the number solidified by the 1922 Colorado Compact, which created the seven basin states that receive water from the river, and its companion, the 1928 Boulder Canyon Project Act, which divvied water up among the three lower-basin states: California, Arizona and Nevada. California, the senior member of the group, receives 4.4 million acre-feet, most of which goes to agriculture in the Imperial Valley; Arizona receives 2.8 million; and Nevada gets a paltry 300,000 acre-feet.

Currently the river is over-allocated. The upper-basin states of Colorado, Wyoming, Utah, New Mexico and Wyoming receive 7.5 million acre-feet; the lower-basin states receive the same amount; and Mexico, since 1944, receives 1.5 million. Add to this the fact that Mead and Powell typically lose between 1.4 and 1.6 million acre-feet a year from evaporation, when they’re full. For the 2008 “water year” (which the Bureau of Reclamation calculates from October 1, 2007 to September 30 of this year), the lakes are expected to lose about 975,000 acre-feet to evaporation—that’s enough water for 3.9 million people for an entire year.

Still, while Mexico and the lower-basin states basically use their full allotment of water from the river, the upper-basin states do not, and this surplus helps to keep pressure off the river’s resources.

Despite the allocation, the Valley uses between 440,000 and 450,000 acre-feet of Lake Mead water a year. What enables us to use more than our gross allocation is that the water authority sends treated wastewater back to the lake and receives “return flow” credits that allow it to withdraw more than its allocation. Last year’s net consumption was 279,000 acre-feet; in other words, we only used 279,000 acre-feet of river water, thanks to these return flow credits.

The Scripps study, published in Water Resources Research last March, argues that global warming is likely to decrease the flow of the Colorado River 10 to 30 percent in the next 30 to 50 years. (If true this would reduce the average flow of the river by up to 4.5 million acre-feet, basically the entire allocation for California.)

Nevertheless, water officials from Las Vegas to Phoenix don’t sound too worried by the study’s prediction that Lake Mead has a one in two chance of drying out by 2021. “I don’t agree with it. He used a fairly simple model,” says Bob Walsh, spokesman for the U.S. Bureau of Reclamation.

Walsh and others point out that the Scripps study assumed that drought conditions wouldn’t trigger any response by the seven states. Walsh notes that upper-basin states have agreed to curtail their water use as the lake lowers in elevation, and that if Mead drops below 1,025 feet “we would declare a shortage, and that shortage would be shared by Nevada and Arizona.”

Still, the SNWA’s spokesman, J.C. Davis, notes that a 1999 study, conducted in the days of a water surplus, concluded that the probability of the lake reaching the elevation it has hit now was zero. “If there’s anything we’ve learned it’s not to get too complacent about how bulletproof our reservoir is.”

To wit: Vegas draws water from Mead through two intake pipes, neither of which is designed to work if Mead’s elevation drops below 1,000 feet. Planning is already under way to construct a third, deeper intake pipe; it will be ready in 2013.

We’re already making the most out of what we’ve got. Groundwater in the Coyote Springs Valley and water from the Muddy and Virgin Rivers will by 2010 bring in an extra 39,000 acre-feet per year.

In addition, the SNWA has agreed to help fund a reservoir project in California called the Drop 2 Reservoir System, aimed at capturing water downstream from Mead. (Walsh gives the example of a farmer requesting water from Mead, then canceling his order when it rains; that water is released but continues “unused.”) The SNWA can tap up to 400,000 acre-feet of this water, at a maximum rate of 40,000 acre-feet per year, beginning in 2011. These measures could provide water for another 316,000 people a year, a figure we are not projected to reach until around 2011.

The SNWA has also made deals to “bank” unallocated water in Arizona and California—the state can withdraw between 20,000 and 40,000 acre-feet a year from Arizona and another 30,000 acre-feet from California, but only under certain conditions, so that water can’t be counted on as a regular allocation. During shortages, for instance, the SNWA may not be able to draw much of anything.

(A water bank is basically a reservoir. It can be an above-ground reservoir, or an underground rock reservoir where unused but allocated Colorado water is injected. Of course, it’s as much an accounting concept as anything—we won’t pull water out of banks we have in Arizona or California; we’ll just pull an equivalent amount from Mead.)

These measures will help, but if growth continues, without a drastic rewrite of the laws governing allocation of the Colorado—and don’t bet on it—the Valley will likely need to explore other options. Which brings us to the pipeline.

In 1989, the Las Vegas Valley Water District filed 147 applications for more than 800,000 acre-feet of unallocated water across 30 basins in rural Nevada. Over the years the authority withdrew some of its applications until it was left with plans to try to tap up to 200,000 acre-feet in six valleys: Snake Valley, Spring Valley, Cave Valley, Dry Lake Valley, Delamar Valley and Coyote Spring Valley.

In April, 40,000 acre-feet was approved in Spring Valley, and an additional 20,000 acre-feet in 10 years could be authorized if there’s no serious environmental impact from pumping; last week, an additional 18,755 acre-feet were approved in Cave, Dry Lake and Delamar valleys. Hearings begin this week before Nevada’s State Engineer, Tracy Taylor, for 51,000 acre-feet the authority has applied for in the Snake Valley, part of which crosses the Utah state line. The SNWA estimates receiving around 100,000 acre-feet from all six basins; with return flow credits that could be stretched to 170,000 acre-feet. Put into context, that’s enough for about 350,000 homes, or more than a million people. It would also reduce our dependence on the Colorado to about 60 percent. “We could get by if we lost the Colorado,” says Scott Huntley, the SNWA’s public information manager. “It would be onerous. It would be difficult. But we would survive.”

The Environmental Impact Statement for the pipeline gives a price tag of $3.5 billion—this is based on the cost of constructing a line capable of moving the full 200,000-acre-foot allotment. (Of that figure, the authority was seeking 167,000; the rest would be earmarked for Lincoln County.)

Since the state engineer will not award all the water the authority has applied for, it’s possible the pipeline would cost somewhere south of $3.5 billion. Then again, these estimates were made in 2007; construction would not be likely to begin until 2012 or 2013, with water beginning to come online in 2015 and 2016—so increased costs for materials and labor will likely drive the cost higher.

And while the main trunk of the line is slated to be 250 miles, with lateral lines feeding off into the valleys to be tapped, and feeders connecting to the wells, the final placement of lines has not been settled.

For ranchers who’ve made their living in rural Nevada, the effects of the pipeline are unclear. Davis says strict environmental regulations—if the authority is granted permission by the state to actually build the line—will ensure that effects of pumping are carefully monitored. Opponents of the line predict the pipeline will decimate the lush landscape and turn the valleys into dust bowls, much as the Owens Valley in California dried up after one-third of the water was siphoned off to Los Angeles.

There is a ton of resistance among activists and ranchers in eastern Nevada to the proposed deal. The line of thinking is that if Southern Nevada had not been so greedy to grow as much as it did, the Valley might not find itself in the mess it’s in today.

“What [SNWA General Manager Pat] Mulroy and the politicians are saying is it’s more important to build more slot machines and tract housing than the lifestyles these folks have had in their families for generations,” says Rake.

As it stands now, 54 percent of the water used in the Valley goes toward residential use, 14 percent goes to commercial and industrial use, the resorts take another 7 percent, as do golf courses, and the rest is split among parks and schools.

Most residential water is used outdoors on landscaping, and so the best way to conserve water in Las Vegas is to cut back on outdoor use in its far-flung neighborhoods.

The SNWA’s chief success has been with its turf-removal program, wherein the authority pays residents by the square foot to remove their lawns and replace them with desert-friendly xeriscaping. Since the program began in 1999 the SNWA has replaced more than 100 million square feet of turf, which has saved an estimated 5.7 billion gallons of water each year, or 17,492 acre-feet. More than 38 million square feet of that grass has been residential. (Last year the authority tried to use satellite imagery to determine how much grass was in the Valley, but difficulties with seeing under trees have made it difficult at this point for the authority to render a conclusive answer on how much grass remains.)

According to the authority’s plan, all conservation efforts have saved roughly 15 billion gallons annually between 2002 and 2007, even though the Valley added 400,000 people.

Currently, the per-capita water use is around 255 gallons—a figure that includes all water use, not just residential water use. An SNWA planning committee authority has set a goal of reducing that amount to 250 by 2010 and 245 by 2035. (Although different cities calculate gallons per day per capita different, the City of Phoenix used about 196 GPCD—though this doesn’t include flood irrigation water some central city residents take from the Salt River Project.)

The rather unimpressive 2035 goal—a quarter-century to achieve a five-gallon reduction?—is, says Davis, likely to be replaced by a target he calls “more robust.” Water planners all agreed 245 was not the end-all be-all, “they just didn’t know what a more realistic number would be.” Although no timetable exists for establishing a more aggressive goal, Davis thinks one will be in place in the next couple of years.

If per capita use is calculated based just on residential water use and not a city’s total water use, then Las Vegas averages around 165 gallons per person per day, according to a study of Las Vegas water efficiency completed late last year by two environmental groups—Oakland’s Pacific Institute and Boulder’s Western Resource Advocates. Los Angeles, by comparison, averaged 125, Tucson averaged 114, and Albuquerque averaged 110. (Those cities do receive twice or three times as much annual precipitation as does the Valley.)

But here is where the SNWA and its critics part ways. No one says conservation isn’t critical, but while Davis suggests indoor conservation is approaching its limits—we’ve basically realized the savings to be had already—Michael Cohen, co-author of a study on water efficiency in Las Vegas, disagrees. “That’s not accurate,” he says. He contends that many older homes still do not have current appliances, and that the authority hasn’t focused as much on indoor conservation as it could.

Cohen’s study concluded late last year that the Valley could reduce its indoor residential water use and its outdoor residential use by 40 percent each, which would save around 79,000 acre-feet a year. This would be achieved through more efficient toilets, primarily, as well as better clothes washers, showers and dishwashers.

Finally, more aggressive rate structures, Cohen notes, would allow users “to see a real benefit when they save water, and recognize that inefficient water use costs them.”

Of course, what is little remarked upon in discussions about water in the Valley is growth. Despite the challenges a growing population has wrought on life in the Valley, it is still the feather in our cap, not only the engine that has helped drive our economy and diversify it beyond gaming, but also our badge of honor that we have become a place so many people want to call home.

That old “6,000 new residents a month” saw may be on the back burner at the moment; drive around the expansive southwest end of the Valley, and you won’t see much that’s new other than a Walgreens here and there.

Nevertheless, the projection for growth in Vegas is enormous; by 2035 we are expected to be home to around 3.7 million people. This figure is forecast by UNLV’s Center for Business and Economic Research. By 2015, the center forecasts the growth rate in the community will slow to under 3 percent per year and fall to around 1.1 by 2029, in line with the anticipated national average.

According to Jon Wardlaw, assistant planning manager of the Clark County Comprehensive Planning Department, the software model that CBER uses to calculate its growth forecast is based on a series of local, regional and national economic factors, not on local policy. In other words, changes in local policy—charging more for water, permitting fewer water hookups—wouldn’t affect the official projection, but they could make a real impact on growth.

Our future growth rate could also be affected by, says Wardlaw, “major changes” in the national economy. A recession or continued high gas prices could have an effect—although the current housing correction may offset it.

“You use up the available talents and resources around you,” Wardlaw says. “Cities do this, just like every other system.” He continues, “There’s only so many people who can move in a competitive environment to any other city. That’s based on job growth. Job growth works on a national scale.”

At any rate, what seems certain is that future growth would better conserve water if it were denser. Build more high-rises and service hundreds of people with a single swimming pool instead of dozens, one greenscape instead of hundreds of back yards.

The authority doesn’t seem to think growth is the big issue. Says Scott Huntley, SNWA public information manager, “We perceive it as security, reducing our reliance on the Colorado River. We do not see this as a growth supply. We see it as a supply to provide security.”

Tell that to developers. What the authority may contend is a backup plan in case we lose the Colorado could be seen by politicians and builders as a free pass to continue to overdevelop the community. You can almost hear that perky sales lady parading some new arrivals around yet another master-planned community. “Oh, don’t worry … we’re getting a lot of water from this giant pipeline …”

Nevertheless, despite the huge number of tourists who descend upon the city, our “manufacturing” footprint is light ecologically. The resorts use only a small percentage of the Valley’s water, and most of it goes to air conditioning. “We build tourists,” says Davis. “That’s what we do.”


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