ASPEN, COLO. (March 12, 2010) – Monday night Aspen City Council voted to move forward with the construction of a pipeline that will allow for safe drainage of Thomas Reservoir above the Castle Creek Valley.
Construction of the pipeline also establishes the path the City will use to move forward towards completion of the Castle Creek hydroelectric project. The City plans to apply to the Federal Energy Regulatory Commission (FERC) for what is called a “conduit exemption” to build the Castle Creek hydroelectric project once the pipeline is under construction.
By delivering water from the reservoir via the pipeline, or conduit, to the Castle Creek hydroelectric plant, the City can take advantage of water for hydropower generation while providing needed flood protection to properties downhill of the Thomas Reservoir, such as the hospital.
A 2007 vote by Aspen citizens overwhelmingly supported the Castle Creek hydroelectric project, with 77 percent of the public voting for it. The project will produce a net 5.5 million kilowatt-hours of environmentally responsible electricity annually. That power production will prevent more than 5,000 tons of carbon dioxide from entering the atmosphere each year.
“The City has been working with consultants on the hydro project since voter approval,” said Phil Overeynder, director of utilities and environmental initiatives. “During their work, the consultants discovered the need for a pipeline to safely drain Thomas Reservoir, citing changes in engineering practices and safety measures from when the reservoir was built in the 1960s.”
The consultants also recommended that because of the need to create a conduit to safely drain the reservoir, the City could be eligible for a conduit exemption for the hydro project based on federal laws and regulations.
A conduit exemption is a more expeditious, less expensive way to bring a hydro project online than a new hydro license application with FERC. The environmental requirements are stringent for a conduit exemption, although a full-blown environmental impact statement (EIS) or environmental assessment (EA) is not required. If Aspen applies for a new license instead of a conduit exemption, FERC may or may not require an EA or EIS. If an EA or EIS is required in the new licensing process, FERC would oversee it. This would result in considerable expense and delay, but no more environmental protection.
The City of Aspen has been undertaking a vigorous environmental analysis of the hydroelectric project. Aspen has consulted with the Colorado Division of Wildlife on the hydro project since July of 2008 and has received input from the public and interested parties in a series of meetings, as well as in written form.
The City is following the Division of Wildlife’s requests for additional studies and has hired an ecological consulting firm to perform additional measurements and studies on stream flows in Castle Creek. The result of the studies may mean more water will be available for instream flows, rather than for creating electricity.
The environmental analysis Aspen has undertaken to date, in addition to the new studies the Colorado Division of Wildlife requested, will be the same analysis that would be required for an EA or EIS. The only difference is, the City is overseeing the studies, which means more of a commitment to local environmental issues, a quicker project time frame and much less money.
“If FERC oversees these environmental analyses, there is no guarantee that they will seek increased instream flow or increased environmental protections,” Overeynder said.
In fact, the City’s experience with FERC on Maroon Creek was just the opposite. For the Maroon Creek hydroelectric plant, FERC required instream flows that were lower that the state’s requirements, meaning less stringent environmental controls. The City, however, has opted to voluntarily uphold the state’s higher standards.
The City tentatively plans to begin construction on the conduit May 1, 2010. For more information on the project, click here.
Aspen’s Hydropower History
Back in 1885, Aspen became the first city west of the Mississippi River to have its street lights powered by hydroelectricity. The power company also provided surplus electricity to homes and businesses – charging $1 a night per light to run, which was pretty impressive for a little mining town in the middle of the mountains, according to the Aspen Historical Society.
In 1888, a Japanese engineer and his assistant came by stagecoach to Aspen to study what Aspen had done with hydropower. Basing their design on what they learned in Aspen, the Japanese built a Pelton wheeler power plant in Kyoto that began operations in 1891.
The original Castle Creek hydro plant in Aspen opened in 1893 as one of Aspen’s first hydro plants. It was fed by flumes from both Castle and Maroon creeks and produced most of Aspen’s power for 65 years. The Castle Creek hydro plant closed in 1958.
The City of Aspen still gets much of its electricity from hydro. The City’s municipal energy supply is 45 percent hydroelectric, including the Ruedi Dam and Maroon Creek Hydroelectric facility. The Castle Creek Energy Plan will add another renewable energy model, with a hydroelectric facility, education center and museum.
“Locally produced hydro-electricity led to Aspen being called ‘The Best Lit City in America’ back in the 1800s. Maybe now, with the return to our hydropower roots, we'll become known instead as ‘The Greenest City in America,’” said Mike Monroney, history coach with the Aspen Historical Society.