Water grab a threat to fishing on the Pan | AspenTimes.com

Water grab a threat to fishing on the Pan

Jeremy Heiman

Fishing guides say a scheme to pump Ruedi Reservoir water to the cities of Aurora and Colorado Springs could create serious problems for the Fryingpan River trout fishery.

The Front Range cities are studying the possibility of pumping 20,000 acre-feet of Ruedi water over the continental divide each winter, reducing the wintertime flow in the lower Fryingpan by as much as one-half. The fly-fishing industry, which brings tourist income to the town of Basalt, could be significantly damaged by the seasonal loss of water.

The so-called “pump-back” is the cheapest of several possible schemes that would bring water needed to accommodate growth in the two cities. The river now runs at rates of between 120 and 150 cubic feet per second in winter, and projections indicate that the pump-back system would reduce the flow to 70 to 90 cfs.

“The bottom line is fish need water,” said Roy Palm, owner of Frying Pan Anglers, a Basalt retail shop and guiding service. Palm said trout, already stressed by having less food available in winter, need a certain depth of water for cover, allowing them to hide from predators.

“It’s a lot more stressful for fish, in their most stressful season,” he said.

Tim Heng, manager of Basalt’s Taylor Creek Fly Shop, said lowering the winter level of the Fryingpan is generally a bad idea.

“I think there’s a huge difference in the health of the river [at reduced flows],” he said. Lowering the water level to that extent could leave trout spawning beds, or redds, high and dry, Heng said, killing off much of the year’s reproductive efforts.

Every fall, trout in the Fryingpan lay their eggs in depressions they make in gravelly, shallow, well-oxygenated areas of the river bottom, Heng explained.

November is the most common time, but they may spawn at any time from October until January or February.

Bill Clark, area habitat biologist for the Colorado Division of Wildlife, said he hasn’t studied the Fryingpan but he’s seen fishery damage in other rivers.

“I’m familiar with winter flow reductions on other rivers, like the Taylor River,” Clark said. “As flows dropped, it exposed brown trout redds.”

Clark said DOW scientists will no doubt be brought in to analyze the river before any decision is made on the pump-back proposal.

Reducing the flow might not reduce the water level or what’s known as the “wetted area” as much as anticipated, he said, but it can reduce the number of insect larvae and the amount of plant life supported by the river.

“Something like that could potentially affect biomass,” he said. “It’s going to be a tricky analysis. We’ll have to look at it carefully.”

Palm said a change in flow patterns can cause ecological changes to which the river takes a long time to adapt. For example, he said, before Ruedi dam was constructed, fish in the lower Fryingpan feasted on abundant stoneflies – large insects that spend the early phases of life under water. Because stonefly nymphs can’t survive the cold tailwater, the outflow released from the bottom of the reservoir, they are no longer present in the lower Fryingpan.

Other aquatic insects have slowly taken their place in the river ecosystem, Palm said, but it has taken a long time. A reduction in winter flows could pose another significant challenge for the river ecosystem.

“It’s going to take mother nature another 20 years to catch up,” Palm predicted.

Palm noted that the Basalt area has become increasingly dependent on fly-fishing-driven tourism in recent years.

“If they ruin that fishery, it’ll really put a bite on a lot of people,” Palm said.

Heng also said he anticipates a significant economic impact if the project is built, and Basalt Town Councilman Leroy Duroux agrees. The town’s fly shops and fishing guides do well in summer and fall.

“It’s one of our major sources of sales tax revenue,” Duroux said. Tourists drawn by fishing bring their nonfishing spouses and families, who often spend some time and money in Basalt’s retail establishments, Duroux said.

Duroux, who represents Basalt on the Ruedi Water and Power Authority board, said the proposal to pump Ruedi water will require much more study. “It’s going to be quite an issue, I think,” he said.


Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.