Construction of the pipeline 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 a conduit exemption to build the Castle Creek project once the pipeline is under construction.

By delivering water from the reservoir via the pipeline to the Castle Creek hydroelectric plant, the City can take advantage of water for hydro power generation while providing needed flood protection to properties downhill of the Thomas Reservoir.

A 2007 vote by Aspen citizens overwhelmingly supported the Castle Creek hydroelectric project, with 77% of the public voting for it. The project will produce a net 5.5M kWh of electricity annually.

“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.

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 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.

Pipeline construction is tentatively scheduled for 1 May 2010. For more information on the project, click on the weblink below.

External weblinks

Castle Creek hydroelectric project