Amy Joi O'Donoghue, Deseret News
Water from the swollen Green River has washed into the state park in Emery County. A number of sandbags have been placed along the banks to prevent the golf course from flooding in an unusually high water year in 2011.

FLAMING GORGE — Efforts to tap water out from the Green River before it impounds Flaming Gorge Dam have earned the Colorado River's largest tributary the dubious  designation as the nation's second most "endangered" river.

The American Rivers organization released its annual rankings of rivers across the country most imperiled because of a wide range of threats: pollution, energy development, inadequate flood control management or diversions the group says would be unsustainable.

The proposed withdrawals are what loom largest for the 730-mile-long Green River that crosses parts of Wyoming, Utah and Colorado because of a pipeline sought by Colorado entrepreneur Aaron Million.

Promoted as a hydro-power project that could also shore up future supplies of water to the Colorado Front Range, the so-called "Million" pipeline would take water from the Green River in Wyoming and convey it to Colorado.

Million has submitted his proposal to the Federal Energy Regulatory Commission and the project's feasibility is being contemplated by the Colorado state water conservation board.

The American Rivers organization said such a withdrawal of water — up to 250,000 acre-feet a year — would decimate recreation, rural economies, critical fish habitat and the water supply for the lower Colorado River Basin.

"The governors of Utah and Colorado must join Wyoming's Gov. (Matt) Mead in opposing the pipeline and standing up for more efficient, cost-effective water supply solutions," the group said.

Still in its infancy, however, the project has yet to be publicly denounced by Utah Gov. Gary Herbert, although state water managers have privately detailed concerns about downstream impacts in Utah if such a diversion were to occur.

The group also pointed to a planned diversion of 53,000 acre-feet of water per year from the Green River for use in a proposed nuclear power plant outside the town of Green River in Emery County. Opponents intent on saving Green River water from that fate have organized a protest parade for Saturday, characterizing the peaceful demonstration as less about the power plant and more about protecting the river.

Although that project is years off as well, river watchdogs say the Green River is coming under increasing attack by nearby energy development of natural gas and would-be oil shale and tar sands proposals.

The Potomac River flowing through Maryland, Virginia, Pennsylvania, West Virginia and Washington, D.C., earned the No. 1 spot for its endangered status because of agricultural and urban pollution. The Chattahoochee in Georgia came in at No. 3 because a tri-state water war is spurring considerations for new dams that would threaten wildlife habitat.

Founded in 1973, American Rivers draws on input from river conservation organizations and the public to compile its list of endangered rivers, drawing attention to the magnitude of the threats facing individual river systems and issuing a call to action for protections. The list of rivers has been issued each year since 1986.

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