From The Aspen Times (Aaron Hedge):
Now, with a deal pending to build a new hydropower plant on the same property that would take 52 cubic feet per second (cfs) from both streams, environmentalists and property owners along the affected shoreline say there’s no way to be certain the streams will sustain fish populations and thus remain healthy. If the City Council approves the project, the city plans to divert 25 cfs from Castle Creek, and 27 cfs from Maroon Creek…
As part of the city’s Canary Initiative — an ambitious effort to become carbon-neutral by 2020 — the hydro project is expected in the next decade to save the city $41,000 a year in energy that it would no longer have to purchase from other power authorities. After that decade, when the $3.92 million in bonds for the project are paid off, the city would save twice that amount, said project director David Hornbacher…
Currently, Castle Creek stays at about 14 cfs in February and March, before starting to rise in the spring. The plant would shut down during winter to maintain the minimum flow, and other power resources, including the Ruedi Reservoir hydropower plant and electricity Aspen buys from a Nebraska power authority, would pick up the load. During other times of the year, Castle Creek typically runs between 50 and 70 cfs. But if the project is implemented, the diversions could extend Castle Creek’s low-water period by four months, calling into question how long the stream can sustain itself, and sustain all the creatures that depend on it, at that level…
The city has yet to apply for permission from the Federal Energy Regulatory Commission, which requires an environmental impact study, to construct the line. In a statement to the City Council this month, project staff recommended that the city not apply for a FERC license because, “Preparation of a an EIS would … delay the project, add to the cost of the project, and jeopardize the project economics.”
More coverage from The Aspen Times (Aaron Hedge). From the article:
City funding for a drainage line from Thomas Reservoir to Castle Creek could go away for the second phase of the construction next year if the Aspen City Council denies the proposed Castle Creek hydropower project, said Phil Overeynder, the city’s public works director. The approximate $2.3 million for the line comes partially from $5.5 million in bonds the city applied for after voters approved the construction of the hydropower plant in 2007. Approximately $126,700 of that money will come from utilities department coffers. The project’s total cost is nearly $6.2 million. The remaining funds will come from a grant of $400,000 and various other sources, Overeynder said. There is no guarantee that the project will stay within that budget, but about $800,000 has been added to it for unforeseen expenditures, according to the City Council application…
The city would have to buy less coal energy from a Nebraska power authority if the plant is approved, project manager David Hornbacher said last week. If the project is not approved, the line will simply empty into Castle Creek just below the Power Plant Road bridge. Efforts to finish the drain line have to wait on approval of the hydropower project because if it is approved, the end of the drain will undergo a completely different construction process, Overeynder said. Either way, the water returns to the stream, through the Penstock drain line if the project is struck down, or through a square concrete tube from the plant to Castle Creek if it is approved. None of the water taken from Maroon Creek will return to it. The hydropower plant is part of the city’s Canary Initiative, a goal to reduce carbon emissions from the city’s energy consumption to zero by 2020. It would draw 52 cubic feet per second from Castle and Maroon creeks. But the drain line will be completed either way, Overeynder said, because the Thomas Reservoir dam poses a threat to the Twin Ridge residential development just down the hill from it. A safety study of the dam, conducted in 1989, said the reservoir posed no public hazard. The Twin Ridge development was not yet built.