Dust Hastens Colorado River Snowmelt, Cuts Flow

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Here’s the release from the United States Geological Survey (Paul Laustsen/Jayne Belnap/Tom Painter):

Dust caused by human activities in the American desert Southwest is a contributing factor in speeding up the melting of snow and reducing runoff in the mountains of the Colorado River basin, according to a new study led by NASA and co-authored by the U.S. Geological Survey.
The findings have major implications for the 27 million people in seven U.S. states and Mexico who rely on the Colorado River for drinking, agricultural and industrial water. The research shows that peak spring runoff comes as much as 3 weeks earlier than before the region was settled and soils were disturbed, but also that runoff may be decreased by more than 5 percent a year compared to pre-settlement levels.

“Reducing dust loads in this area and in similar mountainous areas around the world may help lessen regional effects of climate change,” said Jayne Belnap, a USGS desert soil expert and a co-author of the study.

Until now, scientists had a poor understanding of dust-on-snow events, despite frequent, large episodes of dust deposition. While scientists knew from theory and modeling that dust could be changing the albedo — the solar energy reflectance properties — of snowfields, this study is the first to measure its full impact on snowmelt rates and basin runoff.

The team examined hydrologic effects of human-produced dust deposits on mountain snowpacks over the Upper Colorado River basin between 1915 and 2003. By using a sophisticated hydrological model, the researchers simulated the balance of water in the basin under current conditions and as they existed before the desert Southwest was settled in the mid-to-late 1800s, when grazing and agriculture disturbed fragile desert soils and reduced their natural protection from wind erosion. Lake sediment cores show increased dust deposits in the Rockies by between 500 and 600 percent since the region was settled.

More than 80 percent of sunlight falling on fresh snow is typically reflected back to space. When small, dark particles of dust fall on snow, that percentage drops sharply. Winds blow desert dust east from the Southwest, triggering “dust-on-snow” events. When dust falls on mountain snowfields, it absorbs more sunlight and warms the now “dirty” snow surface, leading to much earlier melt and loss of snow cover.

Some of this warmer snow evaporates directly to the atmosphere, but more importantly, an earlier snowmelt exposes plants earlier as well, allowing them to lose water to the atmosphere through transpiration. The amount that is lost may be more than an annual average 5 percent of the runoff that would have otherwise fed the Colorado River. This 35-billion cubic foot a year reduction in annual runoff is enough water to supply Los Angeles for 18 months.

“The compressed mountain runoff period makes water management more difficult than a slower runoff would,” said Tom Painter, the team leader and a snow hydrologist with NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Actions to stabilize soils and minimize activities that disturb soils could potentially decrease dust emissions and the loss of runoff.”

For example, said Painter, peak runoff under “cleaner” conditions (less dust-on-snow) would come later in summer, when agricultural and other water demands are greater.

This study was co-sponsored by the National Science Foundation. Results of the study, Response of Colorado River runoff to dust radiative forcing in snow, are published in this week’s Proceedings of the National Academy of Sciences. Participating institutions include the National Snow and Ice Center, Boulder, Colo.; U.S. Geological Survey Southwest Biological Center, Moab, Utah; University of Washington, Seattle; Center for Snow and Avalanche Studies, Silverton, Colo.; and the University of Colorado-NOAA Western Water Assessment, Boulder.

More Colorado River Basin coverage here.

Rocky Mountain Arsenal superfund site cleanup update

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From The Denver Post (Bruce Finley) via the Sky-Hi Daily News:

For half a century, the arsenal at Denver’s northeast edge loomed as a secretive complex of more than 250 buildings with signs around it warning “Use of Deadly Force Authorized.” There, the Army made chemical weapons and later, Shell made pesticides. Residential and commercial development gradually encroached on the site. Today, 47 bison roam, raptors circle and badgers burrow on recovering short-grass prairie 10 miles from downtown Denver. “We’ve transformed a very highly contaminated site into a beautiful prairie landscape,” said Carol Campbell, the EPA’s assistant regional administrator handling Superfund cleanups and other officials. “Because it is something that people now can go to and enjoy, it is different from other Superfund cleanup sites.”

The Army still will be responsible for 725 acres of fenced-off land where toxic materials were consolidated and buried. Devices called lysimeters, about 6 feet beneath the clay and dirt, are supposed to verify that surface water isn’t reaching the waste. In addition, monitoring of the already-contaminated groundwater at the arsenal must continue to ensure that lethal chemicals don’t spread farther toward the South Platte River…

Once, homesteading farmers and ranchers lived here. In 1942, the Army established the arsenal to make mustard gas and blister agent to deter Japan and Germany. Then, during the Cold War, factory workers in body suits and gas masks produced thousands of tons of napalm and sarin nerve gas, which was stuffed into bomblets that were placed in Honest John rocket warheads.

Army leaders later leased the site to private companies, including Shell, which arrived in 1952 and for three decades produced chemical pesticides, such as dieldrin, that Shell sold worldwide for agriculture. The liquid waste was dumped in evaporation ponds. Solid waste was dumped into trenches. More than 600 lethal chemicals spread through the soil into groundwater.

More South Platte Basin coverage here.

‘Save the Colorado’ donates to several efforts

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From the Sky-Hi Daily News:

A campaign to help save the Colorado River is supplying $40,000 to causes that aim to protect the Upper Colorado River. Of that money, three-fourths has been donated to the Colorado Environmental Coalition to address new transbasin diversion threats “which have given the Upper Colorado River the dubious distinction of being named one of the ‘Most Endangered Rivers in America’ for 2010.” The Coalition’s “Colorado River Protection Campaign” will “aggressively promote water conservation in Denver and Front Range cities as an alternative water supply source.”

Meanwhile, about $10,000 was donated to the American Whitewater Association, “to protect streamflows — thus boating opportunities — in the Upper Colorado River.”

Called “The Save the Colorado River Campaign Fund,” the nonprofit Colorado River advocacy organization announced its grants for 2010, totaling $150,000 donated to 10 environmental groups from the top of the river basin all the way to the bottom — all working to protect and restore the Colorado River…

The Save the Colorado Campaign Fund also made a grant to the Glen Canyon Institute in Utah for its “Fill Lake Mead First” project, an effort to address the dwindling water levels in both Lake Powell and Lake Mead. The effort may also provide more stable water supplies to Nevada, Arizona, and Southern California…

Additional funding went to:

• Grand Canyon Trust to protect the Colorado River flowing through one of America’s crown jewels, Grand Canyon National Park.

• Citizens for Dixie’s Future in Utah to address the threat of the Lake Powell Pipeline which will drain even more water from the Colorado River.

• Sheep Mountain Alliance in Colorado to protect stream flows and water rights on a tributary of the Colorado River.

• Sonoran Institute of Tucson to try to create an instream flow program for the Colorado River Delta.

• Earthjustice, the environmental law firm in Denver which is working to protect river flows throughout the basin.

More Colorado River Basin coverage here.

Middle Colorado River Watershed Partnership: ‘Watershed 101’ meeting September 21

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From the Aspen Daily News (Brent Gardner-Smith):

The recently formed Middle Colorado River Watershed Partnership is hoping to bring people together to talk about the management and health of the Colorado River between Glenwood and DeBeque canyons, east of Grand Junction. The group hopes to develop a regional “state of the watershed” report as a step toward creating a comprehensive watershed management plan. This past spring, the group also started work on a “watershed inventory” to identify activities currently taking place in the watershed, which is a hotbed of natural gas drilling activity. Until recently, this was one of the few stretches of river in the state that did not have a group focusing on its health and management, as well as educating residents about the watershed’s values, according to a press release from the group. In the future, the watershed group also hopes to conduct educational presentations, field tours and water monitoring.

And in an effort to reach out to local residents, the group is holding a meeting called “Watershed 101” on Tuesday, Sept. 21, at 8:30 a.m., at the Garfield County Re-2 School District administration building in Rifle.

More Colorado River Basin coverage here.

Denver Water, the Colorado River District and others are making progress over the Shoshone water right and Blue River Decree

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From the Aspen Daily News (Brent Gardner-Smith):

The legal settlement could stabilize the flows in the Colorado River at the Shoshone hydro power plant in Glenwood Canyon and reduce the need for large summer flows from Ruedi Reservoir down the Fryingpan River.

“I’m looking to this agreement to forge an entirely new paradigm in the relationship between Denver Water and the Western Slope, as to how we sit down, how we negotiate and how we work together on solving the common problems that we will face in the future,” said Jim Lochhead, the CEO of Denver Water at a water seminar in Grand Junction put on by the Colorado River District.

The pending deal provides for a “certain future for water management” at the Shoshone hydro plant, Lochhead said. And because the deal addresses the use of water from Green Mountain Reservoir, on the Blue River north of Silverthorne, it also could reduce demands on the Colorado River for as much as 500 cubic feet per second (cfs) of water from Ruedi, which disrupts summer fly-fishing on the Fryingpan…

The draft agreement would allow flexibility between the owners of upstream water rights, including Denver Water, in order to maintain consistent water flows past Shoshone as if the plant’s water rights were in effect. “This is a critical element for the economy, the environment and recreation on the Western Slope,” Lochhead said of the Shoshone agreement. The Shoshone water rights, the water in Green Mountain Reservoir, the water in Ruedi Reservoir and fly-fishing conditions in the Fryingpan River are all connected by the water diversion system in the Colorado River basin. And the new settlement with Denver Water could improve the fishing above Basalt.

More Colorado River Basin coverage here.

Fort Collins: 2011 budget news

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From the Fort Collins Coloradoan (Kevin Duggan):

Wastewater rates will increase 9 percent in 2011 and 8 percent in 2012, primarily to continue paying off a $31 million project that is rebuilding a wastewater treatment plant at Mulberry Street and Riverside Avenue. Water rates would increase 3 percent in 2011; no increase is expected in 2012. Stormwater rates are not expected to increase either year.

More Poudre River watershed coverage here.