Grand Canyon Endangered Fish Fail to Recover

FLAGSTAFF, Arizona, July 15, 2004 (ENS) - Scientists for the federal program overseeing endangered fish recovery and sediment restoration in Grand Canyon National Park have come to the tentative conclusion that their main approach has been a "failure."

In a draft paper dated June 22 and circulated last week, eight scientists analyzed the results of water flow variation policies and control of fish in the Colorado River below Glen Canyon Dam.

Members of the Grand Canyon Technical Working Group concerned about ecology and those concerned about power production both show the "surprising" preference for more variable daily flows, the scientists found.

The Colorado River has cut a cleft across Arizona known as the Grand Canyon (Photos courtesy USGS Grand Canyon Monitoring and Research Center)

Since the early 1990s, dam managers have used a specific flow regime from Glen Canyon Dam known as Modified Low Fluctuating Flows, asserting that it would reverse the decline of an endangered fish known as the humpback chub. Instead, chub declines have averaged about 14 percent annually since the early 1990s, the draft paper says.

Emphasizing that the analysis is "a work in progress," the authors suggest moving away from the regime, which restricts dam operators to water releases between 5,000 and 25,000 cubic feet per second.

Restrictions are also place on the hourly rate for increasing and decreasing flows from the dam, not to exceed 4,000 cubic feet per-second and 1,500 per-hour.

The paper is entitled, "Evidence for the Failure of the Modified Low Fluctuating Flow Alternative (MLFFA) to Benefit Most Ecological Resources in Grand Canyon."

"While they may still tinker with the details of their paper, the word failure will continue to ring loud and clear," says Owen Lammers, Living Rivers/Colorado Riverkeeper executive director.

Lammers sees the points made in the paper as evidence for the correctness of the Living Rivers/Colorado Riverkeeper position.

"We've been arguing for years that the Bureau of Reclamation heed the advice of the Fish and Wildlife Service and implement flows more consistent with the river's natural hydrograph if they want to stop the decline of native fish populations," said Lammers.

Previously, dam operators were free to increase or decrease flows based on electricity demand. The paper states that upwards of $50 million annually in hydropower revenues has been lost since the Modified Low Fluctuating Flow Alternative has been implemented.

The endangered humpback chub found in the Grand Canyon's Colorado River

The modified low flow alternative has not succeeded in restoring natural sediments in the canyon, while 95 percent of sediment and nutrients remain trapped behind Glen Canyon Dam. The paper states, "There is currently little debate that ROD flows have failed to produce their intended benefits for sediment resources in Grand Canyon."

In 1994 the Fish and Wildlife Service recommended that the Bureau of Reclamation not pursue the modified low flow alternative, but instead adopt Seasonally Adjusted Steady flows that would have caused releases from Glen Canyon Dam to parallel the Colorado River's natural flow, around 500 to 100,000 cubic feet per second.

But, says Lammers, since such flows would have further compromised hydropower revenue, they were opposed by the Bureau of Reclamation 10 years ago, and are absent from the discussion in the new draft paper.

The Glen Canyon dam on the Colorado above Grand Canyon. (Photo courtesy USGS)

The modified low flow has benefited "the recreational rafting community and trout fishers who care more about catching lots of fish than catching big fish," the paper states, and these stakeholders will want the policy included among future experimental treatments."

But because the strategy is not a "win-win option for all stakeholders," the paper points to the ethical question of who should pay for it.

Currently, power utilities and their ratepayers are subsidizing the modified low fluctuating flows at the cost of some $50 million annually, improving the quality of Grand Canyon for some recreational uses.

"It is one thing to impose such cost to deal with some broad public interest such as protecting an endangered species, but quite another one to impose it for the benefit of particular stakeholders," the authors say.

They urge that the cost issue be addressed "openly and quickly as part of the overall adaptive management planning process, before it leads to a breakdown in the collaboration among stakeholders that has made adaptive management possible in Grand Canyon in the first place."

Living Rivers/Colorado Riverkeeper and more than 200 groups across the country are calling for a new Environmental Impact Statement that evaluates the decommissioning of Glen Canyon Dam to restore the natural process that would reverse the decline of endangered species in Grand Canyon.