Air Date: Week of May 4, 2007

There’s been a drought in the Southwestern U.S. since 1998, but that hasn’t stopped the population in the region from rising by a million people per year. Brian Mann reports on the Colorado River’s struggle to meet growing water demands in the Southwest.

Transcript

CURWOOD: It’s Living on Earth. I’m Steve Curwood. Every day, it seems, thousands of Americans pack up for the sunny skies of the Southwest, especially the booming cities of Las Vegas and Phoenix. The Southwest is a desert, of course, but thanks to the massive water projects of the 1930’s it became hospitable for millions of settlers. But now there’s trouble in the Southwest. The region is suffering through its eighth year of drought with little or no relief in sight. For much of its water the Southwest relies on the Colorado River to brings snowmelt from the Rocky Mountains. But snow patterns are changing and the Colorado is carrying a lot less water than it did a century ago. Overall it seems global warming is hitting the region harder than just about anywhere else in the country

Brian Mann of North Country Public Radio has our story.

DOCUMENTARY AUDIO: Here's where man conquered this mighty river, placing a concrete yoke about its neck.

MANN: This is Hoover Dam on the Nevada-Arizona border. In 1935, Franklin Roosevelt dedicated the massive, gleaming structure, harnessing the Colorado River.

DOCUMENTARY AUDIO: This great achievement of American resourcefulness, American skill and American determination. Hoover Dam brought the desert flood control, a reliable supply of water, electrical power, and more.

MANN: Seventy-five years later, big crowds of tourists squeeze through the dam's visitor center.

ANNOUNCER: Come on in, folks, Find a place where you can see!

MANN: This may be one of the world's modern engineering marvels. But tour guide Bruce Laughlin, who works for the Federal Bureau of Reclamation, acknowledges that the Colorado River's great reservoirs -- at Lake Powell and here at Lake Mead -- were built for much wetter times. For nearly a decade, they've been drying up.

LAUGHLIN: I think we're about 54%.

TOURIST: How long since it's been full?

LAUGHLIN: This lake was filled right to the top before this drought started in 1998. This coming year, they're going to hold as much water as they can in the upper lake because they need to fill up Lake Powell, because it's getting dangerously low. This lake’s probably gonna go down more.

MANN: Scientists now believe that the West was settled during an unusually wet period. The people who built these reservoirs had unrealistic expectations for how much rain and snow would fall each year. Recent climate models predict further drying, less precipitation for the Southwest.

GLEICK: If nature gives us a little less water, then there just is not enough to go around.

MANN: Peter Gleick is a water expert at an environment and resources think tank in Oakland, California called the Pacific Institute.

GLEICK: It turns out that a very small decrease in average flow of the Colorado, in the long run, drains those reservoirs dry.

MANN: A new study by the Lamont-Doherty Earth Observatory at Columbia University -- published in the journal Science -- focused on predictions for the Southwest. Atmospheric scientist and lead researcher Richard Seager says he expects precipitation in the region to drop by 10-20 percent before mid-century. Meanwhile the population of the Southwest is still growing by roughly a million people a year.

SEAGER: With declining water availability there's going to be quite a tussle about who gets the water and whether it's going to be possible to reallocate water in a way that will retain agriculture that's needed, but also sustain a growing urban population.

MANN: Rising temperatures are already shrinking the mountain snow pack, which feeds Western rivers through the summer. In the future, by summer's end, there may be no more snow to melt.

SEAGER: So that natural system of water storage that the water supply system is relying on is going to become less effective.

MANN: Water experts say these incremental changes could disrupt the Colorado River's complicated system of dams, reservoirs and allocation treaties that now supply water to 25 million people.

MULROY: What resources we do have, given what global warming could present to us, could evaporate tomorrow.

MANN: Patricia Mulroy is general manager of the Southern Nevada Water Authority, which is charged with supplying water to the city of Las Vegas.

MULROY: I do believe that the Colorado River is going to be severely challenged as we go through global warming. We're already behind in developing those alternatives on how to protect human existence in the West.

MANN: Conservation is a necessity. And some fast-growing cities have implemented water-use restrictions unheard of in water-rich parts of the U.S. Denver and Aurora, Colorado are seen as models -- as is Tucson, Arizona. Here in Las Vegas, there are actually water detectives, who sniff out waste.

NICHOLAS: Here's the trail of water coming from somewhere up the street here, we'll follow it to its source hopefully.

REPORTER: Pretty good clue trail to follow right there.

MANN: Midmorning, Ken Nicholas, a water cop with the Las Vegas Valley Water District, is patrolling an upscale Vegas neighborhood.

[CAR DOOR SHUTS]

MANN: Nicholas pulls over and talks with a woman outside a suburban ranch house. With its water-hungry lawn and thirsty mulberry trees, this could be a home in Buffalo or Chicago.

NICHOLAS: You have nozzles by the mailbox that are spraying into the street.

WOMAN: I don't live here, I'm just the nanny.

MANN: The Water Authority has combined this kind of enforcement with new incentives, urging people to convert from grass and shrubs to desert plants and rock gardens. But critics say the city isn't doing nearly enough. Down on Vegas's casino strip, there is water everywhere -- flowing from extravagant fountains, gushing over manmade waterfalls.

[WATER SOUNDS]

MANN: Outside the Venetian, one of Vegas's showcase casinos, gondolas ferry tourists through glittering canals. This water is re-circulated and reused, but Jill Rowland-Legan says it's a symbol of the city's outdated thinking.

LEGAN: Are they being smart about growth? Should they have some type of moratorium on growth until we get this water issue taken care of? Are they still catering to the major casinos and the major contractors?

MANN: Jill Rowland-Legan heads the chamber of commerce in Boulder City, a small town that lies between Las Vegas Vegas and the Lake Mead reservoir. Her community has embraced a slow-growth ordinance that limits new home construction.

LEGAN: We don't even take our complete allocation of water here in Boulder City because it's all going to Vegas to make sure that they're taken care of.

MANN: But Patricia Mulroy, with the Southern Nevada Water Authority, says slowing Las Vega's growth is not an option. Construction cranes punctuate the horizon. With eight thousand new residents arriving every month, neighborhoods push steadily toward the arid hills.

MULROY: Every piece of private land is acquired with an expectation to not leave it desert, but to build on it. And the private property owner has a right to develop his property.

MANN: Eighty percent of the Colorado River's water is still used for agriculture and Mulroy says that has to change. The Water Authority has already begun buying up farms and ranches in rural Nevada, in a bid to control more water rights.

But as the drought deepens, Columbia University researcher Richard Seager says rain and snowfall in this region will decline to levels not experienced since the Dust Bowl of the 1930s. Only this time, the dry spell won't end.

SEAGER: That level of reduction was enough to cause really severe trouble and that level of reduction persisting for an even longer period of time will equally cause a lot of trouble.

For Living On Earth I'm Brian Mann in Las Vegas, Nevada.

[MUSIC: Peter Rehberg “TT 1205” from ‘Touch 25” (Touch – 2006)]