For The Colorado River Basin's Endangered Fish, Recovery And Development Can Cooperate

Dec 7, 2015

Some native fish in the Colorado River and its tributaries are struggling to stay afloat. Invasive species, dams and water diversions all complicate the recovery of endangered fish. One long-standing program is part of a multistate effort to save four species of fish native to the Colorado River Basin: humpback chub, Colorado pikeminnow, razorback sucker and bonytail.

It all started in 1988 when the federal government signed an agreement with Colorado, Utah and Wyoming, establishing what's called the Upper Colorado River Endangered Fish Recovery Program.

Endangered fish at various stages of development can be found at the Colorado River Fishery Project, a national fish hatchery in Grand Junction, Colorado. Right now, the hatchery is home to two species, the endangered razorback sucker and the bonytail.

"Back when I first started, pikeminnow were probably doing better," said Dale Ryden, a biologist with the U.S. Fish and Wildlife Service. "There were more big fish throughout the [Colorado River] basin. I had worked here for four years before I ever saw a razorback sucker out of the wild. They just weren't around anymore. Same thing with bonytail. Bonytail were extremely, extremely rare."

The recovery program includes federal and state agencies, environmentalists, hydropower associations and water user groups. Unlike some efforts to conserve other species, it hasn't involved litigation.

"Working toward the same goal of recovering the fish, while allowing water development to continue... those two at first blush don't seem to go together," Ryden said. "But they actually work together very well."

Just to the south of town on the Gunnison River, a tributary of the Colorado, sits a diversion dam built in the early 1900s. It blocked fish from traveling upstream for nearly 100 years, until Ryden said, they put a fish ladder on the dam.

"It goes up and around the Redlands Dam and provides upstream fish passage for native and endangered fish."

The ladder is a selective passage. Biologists use it to trap fish traveling upstream. Then they hand-sort them so only native fish can continue up the Gunnison River. Two similar ladders have been installed along the Colorado and another is in the works on the Green River in Utah.

The Redlands Diversion Dam straddles the Gunnison River, a tributary of the Colorado River.
Credit Laura Palmisano / KVNF

The ladders might help fish get to their upstream habitats, but water levels also matter.

Brent Uilenburg with the Bureau of Reclamation said there is some recognition that "the dams and canals we operate that take water out of the Colorado River Basin have contributed to the decline of the species."

The federal agency operates the largest dams in the West and according to Uilenburg, the bureau used to control water flows to meet irrigation and hydroelectric power demands, leaving the fish high and dry.

"Basically, [the fish] require a large spring peak followed by relatively stable base flows following the spring peak," said Uilenburg. "So what we've done is to re-operate the storage reservoirs to restore it to a more natural condition."

The bureau is also the largest single source of funding for the conservation program. States, water developers, and hydropower associations also contribute, totaling more than $350 million over the past 25 years.

That funding helped the Grand Valley Water Users Association in Grand Junction optimize its system. Before, said Kevin Conrad, the association's operations manager, they diverted more water than necessary.

"Whatever they weren't using, it went out through spillways on the canal back to the river, but it was below a point where the fish couldn't benefit from it."

Conrad said the upgrades also help conserve water and keep it in place for the fish.

The ultimate goal of the recovery program is to remove the fish from the endangered species list. Biologist Dale Ryden said habitat restoration, water flow improvements, hatchery programs, and invasive fish removal are helping the fish rebound.

"Probably the biggest star in terms of recovery prospects is the razorback sucker," said Ryden. "Bonytail are really doing much better with the really robust stocking program."

Humpback chub seem stable, but Ryden said questions remain about the Colorado pikeminnow.

This story comes from 'Connecting the Drops' - a collaboration between Rocky Mountain Community Radio and the Colorado Foundation for Water Education. Find out more at cfwe.org.