ENVIRONMENT

Drowning in Drought

Climate Change and Growing Consumption Compound the West’s Water Woes

Often referred to as the “Lifeline of the Southwest,” the Colorado River serves as the primary source of water for over 25 million Americans spread across seven states—California, New Mexico, Nevada, Colorado, Wyoming, Utah, and Arizona. One of the nation’s longest rivers, it flows 1,450 miles southwest from high in the Rocky Mountains to empty in the Gulf of Mexico and drains a basin roughly 246,000 square miles in size. It also happens to be ground zero for the West’s growing water crisis.

A number of reports have identified the Colorado River basin as one of the areas most vulnerable to climate change, second only perhaps to Alaska, with its receding coastlines. The basin remains in a multi-year drought that began in 1999 and is only likely to become hotter and more arid as the impacts of climate change take hold. Already, the river’s two main reservoirs, Lake Powell and Lake Mead, are only 45 and 50 percent full, respectively. Unless current levels of consumption change soon, there is a 50 percent chance that their water levels could drop below the outlet pipes that as early as 15 years from now—effectively rendering the reservoirs dry.

The basin has grown hotter than any other region in the country over the last three decades.

But the convergence of unsustainable consumption and climate change just might push the water situation in western states around the proverbial bend. And a look at research from recent years underscores the stern warning in the U.S. Global Change Research Program report released by the Obama administration last week that, “Climate change has already altered, and will continue to alter, the water cycle, affecting where, when, and how much water is available for all uses.”

According to a 2007 report by the National Research Council, the basin has grown hotter than any other region in the country over the last three decades. Recent global climate model estimates now project temperature increases of 2 to 4°C by mid-century. The warming has cut into the river’s main input, the snow that falls in the mountains of Wyoming, Utah, and Colorado during the winter and is naturally stored in the form of snowpacks. Reports of below-average snowpack sizes have become more and more common over the last decade, with 2006 marking the advent of record or near-record lows in New Mexico, southern Colorado, and Arizona. Over 90 percent of reporting stations in Arizona were snow-free on January 1—easily the highest figure in the past 40 years. The basin’s snow has also begun to melt earlier in the spring, depriving users, particularly farmers, of the water when they need it most.

In a study detailed last month in the Proceedings of the National Academy of Sciences, Tim P. Barnett and David W. Pierce of the Scripps Institution of Oceanography in La Jolla, California, predicted that climate change could eventually reduce the flow of the river by 10 to 30 percent. Such a significant reduction would result in scheduled water deliveries that go missing 60 to 90 percent of the time by mid-century, potentially creating shortfalls that reach upwards of 1 billion cubic meters per year. That’s about four times the residential water use of the citizens of Denver in 2006.

Though the numbers seem large, Barnett and Pierce believe these delivery shortfalls can mostly be managed through conservation, reuse, transfers, and other measures. Population growth and natural climate variability could complicate these efforts, however, and they caution that the water budget model used by the United States Bureau of Reclamation to plan future deliveries could, by overestimating current river flows, give planners a false sense of complacency.

While the scientists have spoken clearly, it remains to be seen whether western policymakers will react in time and make the crucial reforms needed to avert disaster. Many of the thorniest issues—how to divide water use between municipal and agricultural users, for instance, or how to balance environmental concerns with industry needs—are unresolved, and current initiatives seem either too timid or too risky to succeed.

In California, proponents of desalination are aggressively pushing the process as a potential solution to the state’s worsening water deficits, with plans already in place to build up to 20 new plants. The proposed facilities have encountered stiff resistance from a range of environmental groups, which have assailed them as being too expensive, energy-inefficient, and dangerous to marine life. More cost-effective and practical measures, such as water reuse, water protection and conservation, should take precedence, they argue.

California’s dilapidated water delivery system recently received a $260 million boost from Interior Secretary Ken Salazar as part of the federal stimulus package. The money will primarily be used to build a screened pumping plant, which will protect fish at a dam located on the Sacramento River and increase the amount of water it can dispense to about 150,000 acres of farmland, and to provide relief for the drought-wracked Central Valley.

Several cities have also been experimenting with water rationing and modified water pricing schedules. Los Angeles, which is entering its third year of drought, has just increased prices in an effort to coax residents into reducing their consumption by 15 percent. The city’s Department of Water and Power will also offer residents who replace their grass lawns with drought-resistant plants, mulch, or water-permeable hardscapes a small cash incentive: $1 per square foot. San Diego, for its part, will only allow its residents to water their lawns three days a week and only for ten minutes at a time.

Though promising, especially if planners can implement them on a larger scale, these measures will likely lack the oomph necessary to make a significant dent in the West’s water crisis. More promising is a major water protection initiative for the Colorado River recently proposed by Lake Havasu City Mayor Mark Nexsen at a House Natural Resources Subcommittee hearing. Nexsen called for a comprehensive, coordinated approach to water quality management that would bring together the relevant local and federal agencies that oversee the Lower Colorado River to tackle the threats posed by invasive species, nonpoint source pollution, pharmaceuticals, and wastewater discharge. With appropriate funding, the program would improve the Lower Colorado River’s ecology and increasing the amount of water available to be used.

Other proposed measures could involve the transfer of water between wet areas and dry ones. A study published last month in the Journal of Climate found that, while many of the nation’s rivers would see greatly reduced flows in the coming decades, some, particularly in the Midwest, would see increased flows, thanks to greater precipitation.

Ultimately, we will simply have to make do with less water. As we’re learning to manage our carbon footprints, we will also have to learn how to manage our water footprints, by consuming less and more intelligently.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for Discover, Popular Mechanics, and DeSmogBlog.

Tags: Climate Change, water

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