Colorado River Basin: Climate change scenarios and reservoir depletion risk

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From the Science Blog:

The research team examined the future vulnerability of the system to water supply variability coupled with projected changes in water demand. The team found that through 2026, the risk of fully depleting reservoir storage in any given year remains below 10 percent under any scenario of climate fluctuation or management alternative. During this period, the reservoir storage could even recover from its current low level, according to the researchers.

But if climate change results in a 10 percent reduction in the Colorado River’s average stream flow as some recent studies predict, the chances of fully depleting reservoir storage will exceed 25 percent by 2057, according to the study. If climate change results in a 20 percent reduction, the chances of fully depleting reservoir storage will exceed 50 percent by 2057, [Balaji Rajagopalan, a CU-Boulder associate professor of civil, environmental and architectural engineering] said…

Total storage capacity of reservoirs on the Colorado exceeds 60 million acre feet, almost 4 times the average annual flow on the river, and the two largest reservoirs — Lake Mead and Lake Powell — can store up to 50 million acre feet of water. As a result, the risk of full reservoir depletion will remain low through 2026, even with a 20 percent stream flow reduction induced by climate change, said Rajagopalan.

Between 2026 and 2057, the risks of fully depleting reservoir storage will increase seven-fold under the current management practices when compared with risks expected from population pressures alone. Implementing more aggressive management practices — in which downstream releases are reduced during periods of reservoir shortages — could lead to only a two-fold increase in risk of depleting all reservoir storage during this period, according to the study.

More Coyote Gulch coverage here.

Energy policy — oil shale: No shortage of possible recovery technologies

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Here’s a roundup of the current state of oil shale recovery technologies and leasing pressure from industry from Dennis Webb writing for the Grand Junction Daily Sentinel. From the article:

As oil shale enthusiasts hope for another chance to try out new ideas on federal lands, environmental groups question the need for a new round of RD&D leases. There are plenty of private oil shale holdings where research and development can occur, said Mike Chiropolos of Western Resource Advocates. Meanwhile, for environmentalists and policymakers pondering the potential impacts of oil shale development, recent patent activity gives them some things to think about.

For example, Chevron’s concept involves injecting carbon dioxide into underground shale formations, along with possible combinations of ammonia, acids, hydrocarbons and other substances. Critics worry about protecting groundwater in these and other oil shale approaches, and they fear how much water oil shale development will require. But Chevron has said it will pursue only a process that’s environmentally sound, and it contends its method actually could produce excess water and result in sequestration of carbon dioxide, thus helping combat global warming.

John Dorgan of Golden filed a 2007 patent application involving a concept to produce potable and nonpotable water from oil shale development, with the option of using the nonpotable water to sequester carbon dioxide. Such ideas may hold promise for reducing oil shale development’s environmental impacts. But Chiropolos said that particularly where federal land is involved, any ideas that are pursued, including any incorporating solar, would require a hard look at potential impacts, such as how many acres of land would be affected.

More Coyote Gulch coverage here and here.

Upper Colorado River Endangered Fish Recovery Program update

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Here’s an update on the efforts by Front Range and west slope water providers to provide the necessary water to further the Upper Colorado River Endangered Fish Recovery Program, from Tonya Bina writing for the Sky-Hi Daily News. From the article:

The Colorado River District has taken on the role of fundraising organizer, asking town boards and water districts to contribute money so the West Slope complies to a federal fish recovery program. A pledge, said Daniel Birch of the Colorado River District to Granby and Grand Lake town boards last week, would help the West Slope meet its first obligation of National Environmental Policy Act permitting. The West Slope and East Slope are sharing the cost of $550,000 as each enters the process. Colorado River District fundraising on behalf of the West Slope already has raised just more than $200,000 in commitments. The River District approached 40 water users in the Grand Valley into Summit and Eagle counties…

As part of the Upper Colorado River Endangered Fish Recovery Program, East and West Slope diverters committed to supplying 10,825 acre-feet of water in late summer, evenly split among the two regions. As a temporary solution, Denver Water has been releasing flows from Williams Fork Reservoir to comply; meanwhile, the Colorado River Water Conservation District has been releasing from Wolford Mountain Reservoir for the West Slope’s share. By the end of 2009, however, stakeholders must arrive at a more permanent solution mandated in the program.

Negotiations have led to supplying half of the 10,825 acre-feet out of Granby Reservoir sourced from the Northern Water Conservancy District’s Red Top Ditch Shares (about a $17 million solution) for the East Slope’s share. The other half would come out of Ruedi Reservoir near Basalt for the West Slope’s share. The plan also includes using excess storage capacity in the Green Mountain Reservoir. Contracting with the federal government to have water shepherded from Ruedi to the critical section of the Colorado could cost West Slope water users about $8 million, according to the Colorado River District. For this reason, the district is working on legislation it plans to introduce to Congress, asking for forgiveness of that cost…

Both the Towns of Grand Lake and Granby agreed to consider the $5,000 while crafting next year’s budget, a process starting in August. Grand County Water and Sanitation No.1 and the Winter Park West Water and Sanitation District have also made commitments, according to Birch.

More Coyote Gulch coverage here and here.