The Watershed of the American Southwest
Although dry and remote, Greater Canyonlands forms the heart of the American Southwest’s greatest waters– the Colorado River basin. Within the borders of the proposed Greater Canyonlands National Monument, the Green, Dirty Devil, and San Rafael Rivers wind south to meet Colorado, followed soon thereafter (in Glen Canyon National Recreation Area) by the San Juan River.
Together these rivers create “the lifeline of the Southwest and… the economic foundation of a significant portion of the western United States.”
- More than 40 million people depend on the Colorado River for their water needs.
- The Colorado River irrigates more than 4 million acres of farmland, producing 15 percent of the nation’s crops and about 13 percent of its livestock.
- In the Southern California counties that rely most predominately on Colorado River water, agricultural industries, including farming, food processing, and supporting businesses, produced $48 billion in sales and directly employed 160,000 workers in 2010.
- Equally important, the Colorado River Basin supports world-class rafting and freshwater fishing industries, with the total economic value of fishing, hunting, and wildlife viewing throughout the basin calculated at more than $10 billion annually.
Increased oil and gas drilling and tar sands, potash, and uranium mining present major concerns for the watershed. Both the use of water in these extraction efforts and the resulting pollution would place significant demands on the Colorado River and its ecosystems.
In particular, tariff sand extraction would use vast water quantities and would fundamentally change the water supply for the entire Southwest.
Red Dust on White Snow
“Make no mistake; the dust-on-snow phenomenon is real. And it’s making a mess of things in the Colorado Rockies,” writes Denver Post columnist Scott Willoughby.
Nowadays, dust is being deposited at rates approximately five times those of the era predating European settlement. When that dust lands on snow, it causes enhanced solar radiation absorption – just like wearing a dark t-shirt outside on a hot sunny day. Here’s how it works: Wind storms pick up desert soils from the Colorado Plateau that have been disturbed by dirt and gravel roads and activities such as drought, fire, oil, and gas development. Those wind storms then deposit that dust on mountain snowpack throughout the Rockies.
That enhanced solar radiation causes snow to melt faster and sooner than it normally would.
As Willoughby points out: “It’s not an issue to be underestimated. Studies dating to the moderately dusty years of 2005-08 show that the dusty snowpack robbed the Colorado River of 5 percent of its flow before reaching the Grand Canyon, equating to about 750,000 acre-feet annually, or about twice what the city of Denver uses [each year]. During 2009, 2010, and 2013, scientists observed unprecedented amounts of desert dust falling on Colorado snowpacks, about five times more than observed from 2005-08.”
We can’t afford to lose this precious water supply, especially because various models predict that climate change will cause an additional 7 to 20 percent reduction in current runoff in the Colorado River Basin. According to the USGS, climate change “will profoundly affect water and living systems in the Colorado River Watershed.”
Early snowmelt also causes peak runoff to occur on average three weeks earlier than it would without the impact of dust, diminishing the amount of water available later in the season when it’s needed the most.
Early snowmelt is already threatening Colorado’s ski industry. Research shows, for example, that dust deposition in 2009 caused snow cover to melt 48 days earlier than normal in the San Juan Mountains of western Colorado. And the economic costs of this change in snowfall and snowmelt patterns are mounting, with research showing that the $12.2 billion Colorado ski industry has already suffered a $1 billion loss and shed 27,000 jobs due to global warming, which is regionally exacerbated by dust on snow.
An even larger issue is how a decrease in Rocky Mountain snowpack will affect downstream users, including California growers who rely upon the Colorado River to irrigate their crops. After all, the Colorado River’s largest reservoir lies not behind Hoover or Glen Canyon Dams, but in the unmelted snowpack stored in the Colorado Rockies each winter and spring.
While dust is a natural phenomenon, research shows that activities that destabilize soils–such as off-road vehicle use and oil and gas development–greatly increase the susceptibility of desert soils to wind erosion. The development of oil and gas fields in Greater Canyonlands would be particularly harmful to efforts to mitigate the impact of climate change in the Rockies; not only do these areas create industrial-level carbon emissions, but they also come with their own network of roads, pipelines, and drilling pads that disturb thousands of acres of native soils.
Scientists also tell us that the Colorado Plateau–which includes Greater Canyonlands– and the Great Basin are likely the major source of dust on snow in the Rockies. And the federal government has identified Greater Canyonlands as one of the areas most vulnerable to climate change. Thus, mitigation of human disturbance here is critical. “Dust has to become part of [our] land management goals,” says Jayne Belknap, an ecologist with the U.S. Geological Survey, in a recent article from Climate Progress on “How Dust on Colorado’s Snow Could Ruin Your Salad.”
Protecting Greater Canyonlands as a national monument would be a good first step to mitigating the dangerous feedback loop where dust on snow exacerbates the harmful impacts of climate change in the Intermountain West and threatens the water supply upon which one in ten Americans and fifteen percent of our nation’s agriculture rely.
A Greater Canyonlands National Monument would ensure that some of our nation’s most spectacular scenery is protected from activities that not only mar the landscape and release harmful carbon emissions but also destabilize soils in one of the most critical watersheds in the West, threatening water supplies for millions.