Gunnison River: New flow regime in Black Canyon takes effect

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Last year irrigators, conservationists, bureaucrats, sportsmen and others reached a landmark agreement on flows in the Gunnison River through Black Canyon of the Gunnison National Park. Here’s a release from Colorado Trout Unlimited and Western Resource Advocates about the program’s first year:

May 7, 2009

Drew Peternell, Trout Unlimited, (303) 440-2917, x. 102
Bart Miller, Western Resource Advocates, (303) 444-1188, x. 219

In Black Canyon, a New Era of Water Management Begins

The rebirth of a Colorado river begins this month, as water officials start to put the landmark 2008 Black Canyon of the Gunnison settlement into effect.

On May 7, U.S. Bureau of Reclamation (BOR) operators made the first release in a new flow regime that is expected to help restore the Gunnison River canyon ecosystem and return it to a more natural state.

“After years of hard work by Trout Unlimited and other conservation groups, this is the payoff,” said Drew Peternell, director of Trout Unlimited’s Colorado Water Project. “With these renewed flows, the Gunnison River through the Black Canyon will experience a rebirth, and its priceless natural resources will be safeguarded for generations to come.”

After 30 years of uncertainty and nearly a decade of contentious legal wrangling, a Colorado court earlier this year approved a final settlement that set up enhanced flows to protect the natural resources of the Black Canyon of the Gunnison National Park, including its world-famous trout fishery.

Under the Bush administration, the National Park Service had attempted to abandon some of its water right in the Park. But a team of conservation groups, including Trout Unlimited and Western Resource Advocates, challenged the decision in federal court and won—and the historic 2006 ruling for the first time established the U.S. government’s responsibility to maintain the park’s water right and natural resources.

Two years later, the state water court approved an historic settlement that guarantees the river a year-round minimal base flow of 300 cubic feet per second and higher annual peak flows and shoulder flows, the size of which would be tied to natural water availability each spring. These variable flows will help restore the balance of the river’s habitat and ecosystem.

This spring, the settlement will be implemented for the first time. In the coming week, water releases from the Aspinall Unit will increase each day until reaching a peak flow of about 6,000 cfs in the Black Canyon on May 13, after which the releases will begin to drop until leveling off at approximately 1,900 cfs in the Black Canyon and Gunnison Gorge on May 21, according to BOR officials.

Among other benefits, the higher flows will help flush out sediment deposits that have caused whirling disease and other problems for trout, clear out encroaching vegetation and woody debris, and help maintain the river channel.

“2009 is an important milestone,” said Bart Miller, attorney for Western Resource Advocates. “It marks the year when flows in the Gunnison strike a new balance. The new flow regime shows what dedicated stakeholders can do when they put their heads together—meet important ecological needs as well many other water uses in the basin.”

In coming months, TU and other groups will monitor the new flow regime for compliance with the settlement. And they will watch closely as a renowned Colorado river gets a new lease on life.

The conservation groups involved in the effort were Trout Unlimited, Western Resource Advocates, Environmental Defense Fund, High Country Citizens’ Alliance, National Parks Conservation Association, The Wilderness Society, Western Colorado Congress, and Western Slope Environmental Resource Council. In addition to in-house attorneys at Trout Unlimited and Western Resource Advocates, the law firm of Hogan and Hartson provided pro bono legal service to the conservation team.

More coverage from the Denver Post (Mark Jaffe):

Releases will increase over the next few days until the Gunnison River in the canyon rises to six times its current flow — aiming to simulate natural spring runoff and help restore the park’s river ecosystem…

The state was wary of the park getting a federal water right because virtually all water rights in Colorado are granted by the state, Peternell said. Hydropower and agriculture interests both looked to guard their use of Gunnison River water, and there was resistance to sending so much water down the river rather than storing it, Peternell said. An agreement balancing all the interests was finally struck Jan. 31, 2008, and filed as a decree in Colorado water court.

On Thursday, the first water from that accord flowed out of the Aspinall Unit. “We are ramping up gradually, in part for safety reasons. We want to give people in the canyon ample time to get out before the high water,” said Dan Crabtree, the bureau’s water-resources group chief. The river’s level at the park’s entrance is projected to rise from 3.5 feet to 8.5 feet. Since the unit — a series of three dams and reservoirs — was begun in 1963, average peak flows through the Black Canyon have dropped to roughly 1,700 cubic feet per second from more than 4,500 cfs, according to an Aspinall environmental assessment. Before 1937, the average peak flow was more than 6,000 cfs. By next Thursday, with additional releases from Crystal Reservoir, the flow will rise for 24 hours to nearly 6,000 cfs from 1,000 cfs.

More from email from Reclamation (Dan Crabtree):

Reclamation has developed an operation plan for the upcoming weeks which will allow the Black Canyon Water Right to be met and satisfy other project purposes as well. The May 1st forecast for the April through July runoff into Blue Mesa Reservoir is 690,000 ac-ft. Consequently, the Black Canyon Water Right calls for a 24 hr peak flow of almost 6,000 cfs (5,864 cfs according to the decree). Next week, side-inflows into Crystal Reservoir are expected to maintain a level at which releases from Morrow Point by-passes can be minimized and Morrow Point Spillways will not be required to meet the 6,000 cfs peak. By-pass releases from Morrow Point Reservoir will be adjusted as necessary so that, when combined with side-inflows, the water right will be satisfied. The Gunnison Tunnel is expected to divert approximately 900 cfs during this period. The Colorado Basin River Forecast Center tells us there is a 50% chance the North Fork of the Gunnison will also peak next week so we will be monitoring high water conditions below its confluence with the Gunnison.

Beginning Thursday, May 7th, releases from Crystal Reservoir will increase each day until reaching approximately 6,900 cfs (6,000 cfs in the Black Canyon) by the evening of Wednesday May 13th. Releases will begin to ramp down starting the morning of Friday, May 15th and will level off at 2,800 cfs (1,900 cfs in the Black Canyon and Gunnison Gorge) on the afternoon of Thursday, May 21st. As always, this operation may be modified at any time in response to current or future hydrologic conditions, and safety or mechanical issues.

Click here to get to the meeting minutes from the April Aspinall Unit operations meeting.

More Coyote Gulch coverage here and here.

3 thoughts on “Gunnison River: New flow regime in Black Canyon takes effect

  1. I wonder how this will effect the fishing directly after the huge run offs. I’m backpacking into the Redrock Canyon area a week after the flows are to subside…Any comments or sugguestions would be appreciated. Thanks.

    1. Jim,

      I think you’ll just have the standard spring runoff in the side canyons. The only problem will be if you have to cross the Gunnison with no bridge. Runoff this year will likely be normal as the snowpack was about normal everywhere. Really warm weather could change that as could spring storms. If I were you I’d contact the park rangers — they’ll know the current condition.

      John Orr

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