Bureau of Reclamation wants to flood Grand Canyon to save native fish
by Shaun McKinnon, reprinted from The Arizona Republic
ederal officials want to flood the Grand Canyon and evict thousands of nonnative fish from the Colorado River next year in a repeat of a controversial 1996 experiment that produced inconclusive results and temporary benefits.
The US Bureau of Reclamation presented its proposal at public briefing sessions in Phoenix and Flagstaff, outlining a plan scientists hope will begin to mend an ecosystem bruised more than 40 years ago by the construction of Glen Canyon Dam.
The two-year experiment calls for artificial floods similar to one staged in 1996, aimed at rebuilding some of the riverbanks and beach habitats along the canyon floor. Scientists also would remove as many as 20,000 nonactive rainbow and brown trout from the river in an effort to improve conditions for endangered native fish such as the humpback chub, whose numbers have dwindled from 8,000 to about 2,000 since the mid-1990s. The trout are thought to prey on the chub.
The experiments are part of a long-term goal of correcting problems created by the dam, including the loss of natural sediment, a drop in water temperature and the introduction of nonnative fish. The floods, for example, attempt to mimic temporarily the natural behavior of the river, whose flows once fluctuated significantly over a year's time.
A 1996 flood, presided over by former Arizona Gov. Bruce Babbitt, then-Interior Secretary, appeared to shore up some of the damaged beaches with few of the side effects predicted by critics. Later studies suggested the flood's effects were short-lived and did little to help the endangered fish.
Several environmental groups say the latest plan is too little too late, especially for the chub and other species struggling to survive in their altered environment. Owen Lammers, executive director of Living Rivers, called the proposal the latest act in a six-year-long charade by the bureau and water and power interests whose inattention has threatened the river's ecosystem. They just want to tell the public, 'we tried,' and then go back to operating the dam however they wish once the fish are extinct, Lammers said.
He said the experiments fail to reintroduce any new sediments and nutrients critical for native fish habitat and don't address the need to raise water temperatures below the dam. Native fish struggle to survive in the colder river, while the nonnative predators thrive.
Nikolai Ramsey, program officer for Flagstaff-based Grand Canyon Trust, said the experiments will produce benefits, but delays in their start have compromised the overall goals.
Changes in the river's flow should have begun in early September to properly prepare the river for a full-scale artificial flood, Ramsey said. He also worries that the government has lost sight of the endangered fish, which continue to die. We should be putting our efforts more strongly into saving the chub, Ramsey said. This is a fish that has lived in the Colorado River and only the Colorado River for 2 million years and now is close to extinction because of what we've done to the river.
Ramsey predicts stiff opposition to the government's plan from both environmentalists and others with a stake in the river, including sport fishery groups.
The timing and scale of the experiments will hinge in part on weather conditions in the coming months. Drought choked summer runoff from the Paria River, a tributary of the Colorado that in normal years would have shifted sand and sediment downstream into position for the artificial floods. Scientists don't yet know if there's enough to stage a flood by January.
Randy Peterson, manager of the bureau's upper-Colorado environmental resources division, said that plans allow scientists to adjust the schedule for the larger floods, which send water gushing through Glen Canyon Dam's rarely used bypass tubes. Those floods would take place as soon as the Paria delivers enough sand and sediment.
The fish relocation could begin as early as January, when above-normal flows from the dam would be used to disrupt spawning. Later in the year, biologists would use electrical charges to stun the fish at various spots along the river. The nonnative fish would be removed and relocated, while native species would be left in the river.
Living Rivers, PO BOX 466, Moab, UT 84532; (435) 259-1063; infolivingrivers.org; www.livingrivers.org