The giant sucking sound that will soon be the Animas-La Plata water diversion project south of Durango is expected to impair downstream fish habitat and could threaten one of the state’s most excellent trout-fishing sites.
Just downstream of where massive pumping stations are to be positioned along the banks of the Animas River is a 2 1/2-mile stretch of premier fly fishing known as the Purple Cliffs. It is one of 13 Gold Medal Water stretches designated in Colorado and the most recent to be approved by the Division of Wildlife, earning the coveted designation in 1993.
But the question of how well this famous fat-trout section of the Animas River — from the Lightner Creek confluence to the new highway bridge accessing La Posta road — will fare once A-LP begins pumping large volumes of water into nearby Ridges Basin has wildlife officials and anglers concerned.
“Bottom line is that under full operation of that project there will be less water in the Animas River, less habitat, less food and less fish, so there is no question in my mind that it will be a negative to the trout fishery,” said Tom Knopick, owner of Duranglers Fly Shop in Durango. “The negative impact of A-LP is discouraging. That section is unique in that the Animas is one of the only rivers that has improved in water quality over the last 20 years.”
Before 1983, the entire Animas River was not worth fishing because the waters had been heavily poisoned by extensive mine tailings upriver. But successful mine clean-up projects at the headwaters near Silverton brought a healthy fish population back within five years and led the way to the Gold Medal status.
The special regulations require flies and lures only, and a two-fish bag limit of 16 inches minimum length. The top designation is designed to encourage a population of the larger trout favored by catch-and-release fly-fishing enthusiasts.
Dewatering a river is never good for its overall ecology, but the impressive health of the Gold Medal section now could be its saving grace once the pumping begins in 2009, reports Mike Japhet, senior fish biologist with the DOW.
The minimum criteria for Gold Medal Status on the Animas is an average of 144 trout per mile that are at least 14 inches in length, plus at least 60 pounds of trout bio-mass (the food and vegetative habitat) per surface acre.
Recent fish counts on that section show that it continues to improve significantly. In 1998, there were 420 fish of 14 inches or larger per mile and 65 pounds of biomass per surface acre. In 2000, those numbers jumped 828 per mile and 144 pounds per acre respectively.
“So even if there is a 50 percent reduction in fish numbers and biomass, the river would still qualify, and that gives me enough comfort to say with some assurance that while there is no question A-LP will affect the number of fish the river can sustain, it is not enough to cause the Gold Medal designation to be lifted or removed,” Japhet said.
Also, minimum bypass flows must be adhered to during operations of the Ridges Basin Reservoir pumping schedules in order to protect the fishery, according to Harold Jensen, the Bureau of Reclamation environmental specialist for the project.
The water in the river in excess of downstream water rights can be pumped into Ridges Basin, a 120,000-acre-foot off-site storage reservoir. But the bureau, the federal division responsible for the half-billion-dollar project, has committed not to operate the pumping plant if Animas flows at the pump station, located at Santa Rita Park, are below the following levels: 160 cubic feet per second from October through November, 125 cfs from December through March, and 225 cfs between April and September.
“It allows for spawning in October and for more water during the warmer months,” Jensen said. “Very rarely would you get down to 225 cfs in the summertime because of the senior downstream irrigation and project water rights,” which legally must flow downriver and therefore contribute to the amount of water passing through the Gold Medal section. The bypass flows apply during the initial filling of the reservoir as well, he said.
Japhet said there will be mitigation by the Bureau of Reclamation to augment the loss of water due to the project, “but it won’t be water, instead it will likely be removing check dams further downstream or installing fish ladders to accommodate spawning of native sucker fish and their ecology.”
He predicts that the cold-water trout now hanging on in the lower Animas as it approaches the San Juan River at Farmington, N.M., will disappear once the project is in full operation because of shallower water levels and higher temperatures. That impact will also exacerbate the algae-bloom problem already seen around Bondad because there will be less dilution of agricultural runoff and waste discharges from the Durango sewer plant, he said.
“The drought is already doing that to us, but it is natural. (With A-LP) it will kind of be like living in an extended drought period if you are a fish in the lower Animas River because it is going to get a lot drier than they are used to,” Japhet said.
He added that, when filled, Ridges Basin Reservoir will be managed by the DOW as strictly a trout fishery. Bass fisherman have been hoping it would include the popular sport fish, but Japhet said that species will not be included because of the danger that bass could escape into the Animas. If they did, the predacious bass would “undoubtedly wreak havoc” on endangered fish species as they did after escaping into Colorado’s Yampa River from Elkhead Reservoir.
Trout Unlimited’s Five River Chapter and other watchdog groups in Durango have been monitoring the future of the well-loved fishing spot on the Animas. Board member Dennis Lum said he is “cautiously optimistic” the Gold Medal Water will be preserved.
“ The Animas is one of the last, large freestone rivers in the state and we are real concerned that nothing affect the fishery,” Lum said. “If they do what they say they are going to do, it looks like it will not be as bad as we thought it might, although I believe the minimum bypass in the summer months should have been higher.”
But distrust of the Bureau of Reclamation runs deep with fishermen, Knopick said, citing the impaired fishery and shallow flows on the lower Dolores River below McPhee Dam.
“ Time will tell if it survives,” he said. “I’ve been around enough water projects to know that what they say is not always what they do. The bureau always seems to leave itself enough wiggle room to operate in a different manner than what has been talked about and that is my big concern. If they do what they say, it might not be that dramatic, but I don’t believe them.”