Energy policy — hydroelectric: How will the city’s proposed hydroelectric plant impact the riparian and aquatic environment?

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From The Aspen Times (Aaron Hedge):

“This project is an ecological train wreck,” said Tom Starodoj, a resident of the area, during Wednesday’s public meeting.

The study established that Castle Creek needs at least 13.3 cubic feet per second at its lowest point of the year, which is typically between January and April when the cfs hovers around 20. Phil Overeynder, the city’s public works director, said in the meeting that figure is easily sustainable.

Overeynder said the city remains confident in the numbers the study relies on, which were generate in the early 1990s. Bill Miller of Miller Ecological Consultants, Inc., which conducted the study, said the life of the waterway will remain healthy if the project is completed.

Miller assured skeptics that the vibrancy of the stream depends not on a certain cfs during dry times, but on the complex cycle of peaks and furloughs it goes through every year. He said the city would not have the flexibility to drain the stream, though it is legally within its right to do so.

More coverage from Curtis Wackerle writing for the Aspen Daily News. From the article:

a group of homeowners who live along the creek are skeptical of the effect a proposed hydropower facility would have that would draw up to 25 cfs from the creek. What happens when the creek is running at 50 cfs? Will the plant still take its 25 cfs? And how is that not going to adversely affect the stream?

Those questions and others were posed in a meeting on the Castle Creek hydropower facility Wednesday night at the Aspen Center for Environmental Studies. Most of the 17 or so members of the public in attendance were Castle Creek homeowners who question whether the project is the right thing to do…

Miller noted, however, that in a naturally flowing mountain stream like Castle Creek, the peak flows seen during the spring runoff are the most critical to ecology. Spring flows on Castle Creek tend to peak in the 700 cfs to 800 cfs range. This year, the creek peaked above 900 cfs. This inundation of water helps reinvigorate the channel and the plant life on the sides, Miller said. “Protecting that peak is probably as important or more important than preserving minimum flows,” he said.

Mark Uppendahl with the Colorado Division of Wildlife defended the 13.3 number, calling it the “amount of water we feel preserves the natural environment to a reasonable degree.”

More hydroelectric coverage here and here.

One thought on “Energy policy — hydroelectric: How will the city’s proposed hydroelectric plant impact the riparian and aquatic environment?

  1. What most people don’t understand about hydro power is that you design the system around the flow duration curve, which basically tells you where you can operate the system economicaly according to where the flows are on an annual basis. The marginal cost of building a system to take the bigger flows during runoff aren’t worth it because of the short duration, nor do you size the system using the minimum stream flows, because likewise you won’t make enough power to pay for the system and also because all streams in Colorado have a legislated minimum stream flow that has to be maintained. So you size the system above minimum flows.

    All forms of producing energy, renewable or not, have impacts. Run of the river hydro projects (those without dams) like this one, designed well, are very environmentally benign, and will run for 50 years or better, and produce far more energy than that what it takes to build them. Run of the river hydro only takes flows out of the stream between the initial point of diversion and the turbine, and flows downstream of the turbine are as if the power plant were never there. Aspen’s history of using hydro runs deep, the public just needs to be better educated. The Aspen Water Dept. also have really good experience managing these systems (Ruedi, among others), and picking good equipment. I hope that the public can settle down on this so another good hydro project can come online.

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