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Boulder Canyon Hydroelectric Plant Modernization Project

Boulder Canyon Hydroelectric Plant Modernization Project

The Boulder Canyon Hydroelectric Project (BCH), which includes Barker Reservoir, the Barker Gravity Pipeline, Kossler Reservoir, the Boulder Canyon Penstock and the Boulder Canyon Hydroelectric Plant, was built in 1910 by the Eastern Colorado Power Company for the sole purpose of hydroelectric power production. During the 1950s, the facilities also began providing water for Boulder's municipal water supply.

The Modernization Project

Boulder purchased the BCH from the Public Service Company of Colorado in 2001. At the time of purchase, there were two 10-megawatt (MW) turbine/generators in the power plant, only one of which was operational. The operating unit was over 50 years old and nearing the end of its useful life. Boulder determined that a new, five-MW turbine/generator would be needed to keep the facility in operation. The smaller unit would be more appropriately sized for the plant and would extend the life of the hydroelectric project for at least 50 years. In addition, even though smaller, the new turbine/generator would be able to produce 30 percent more energy because it is more efficient.

In 2009, the U.S. Department of Energy (DOE) provided a grant opportunity for projects such as the BCH modernization project. Funding for the grant program had been appropriated under the American Reinvestment and Recovery Act (ARRA), commonly referred to as "stimulus money." Grant applicants were required to demonstrate their readiness to move forward with a project that was in the public's best interest and that would utilize American made goods and services to create or preserve jobs within the U.S. Boulder received $1.18 million toward a total estimated project cost of $5.155 million from DOE to proceed with the modernization project.

The goals of the modernization project included:

  • increasing renewable energy generation and operating efficiency;
  • increasing safety and eliminating environmental hazards at the plant;
  • modernizing and integrating project control equipment into Boulder's municipal water system; and
  • preserving significant historical engineering information.

To accomplish these objectives, the project included:

  • removing one of the two existing 10 MW turbines;
  • installing a new five megawatt turbine/generator. This unit could generate up to 580,000 megawatt-hours of electricity during its 50-year lifespan.
  • leaving the other turbine/generator, which had stopped working in 2000, on site for historical purposes;
  • enhancing lightning protection;
  • removing and replacing an old oil storage tank;
  • upgrading wiring;
  • installing a state-of-the-art turbine isolation valve;
  • installing remote monitoring and operation equipment, and;
  • removing and replacing several aging, oil-cooled transformers adjacent to Boulder Creek.

The new five megawatt turbine/generator is appropriately sized for the water flow that is currently available. This unit could generate up to 580,000 megawatt-hours of electricity during its 50-year lifespan. Despite its smaller size, the new turbine could still generate up to 30 percent more energy than the old turbines because it is more efficient.

Other improvements included:

  • enhanced lightning protection;
  • removal and replacement of an old oil storage tank;
  • upgraded wiring;
  • installation of a state-of-the-art turbine isolation valve; and 
  • remote monitoring and operation equipment.

Historic Preservation

The Boulder Canyon Hydroelectric Project is considered historically significant on a national level and is eligible for nomination to the National Register of Historic Places. The BCH historical significance derives from unique engineering features, construction difficulty and innovative construction techniques, and association with persons significant to the history of both Colorado and the U.S. When completed in 1910, it was the highest head (water pressure) hydroelectric facility in the western U.S. In 1994, the Boulder Canyon penstock was awarded the Historical Welded Structure Award by the American Welding Society as it was the first structure in which acetylene welding in conjunction with the ball-peen welding procedure was used. This method significantly advanced penstock technology.

The city contracted with URS Corporation and Native Cultural Services to complete detailed records of the historical equipment prior to removal in order to preserve the design, construction and operational history of the original facility. This process included extensive photography of the inside of the power plant, researching historical documents and preparing a narrative history of the hydroelectric project. Wherever possible, the city has preserved historical equipment in place for educational and display purposes.

Environmental Impacts

This project had few negative environmental impacts, since the modernization involved the existing plant, and no operational changes. During its lifetime, the project is expected to have several positive environmental impacts. The new turbine/generator is projected to displace the need to burn more than 300,000 tons of coal – the amount that would be needed by a traditional coal-fired plant to generate the same amount of electricity – during its lifetime. It will also help prevent the related greenhouse gas emissions.

The city implemented a comprehensive recycling program during the construction phase of the project. Concrete, cast iron, steel and copper removed from the plant were recycled, and recycling revenues helped offset project cost. Pieces of equipment that required removal will either be retained in storage for their historical value or offered to other hydro plant operators for reuse.

Estimated Increase in Energy Production and Environmental Benefits of the Project

Boulder's eight hydroelectric power plants are owned by the city's Water Utility, and all electricity generated is sold to the local electric utility. Revenue from the sale of hydroelectricity is used to offset a portion of the capital and operating costs of the Water Utility, which would otherwise have to be paid by Boulder's water customers. Revenue from the city's eight hydroelectric facilities is about $2 million/year.


Old 10 Megawatt Unit

New Five

Change from Existing

Expected Lifespan (Years) 5 50 45

Average Annual Megawatt-hours




Total Lifetime Megawatt-hours




Coal Consumption Offset (Tons)




SO2 Emissions Offset (Tons)




NOX Emissions Offset (Tons)




CO2 Emissions Offset (Tons)




American Recovery and Reinvestment Act (ARRA) Funding

The federal government monitors the number of jobs created or preserved through federal project expenditures. City consultants and contractors reported the number of hours they spent working on the project each quarter, and an estimate of jobs created or preserved by the federal project funding was reported each fiscal quarter.

Since beginning the project in January 2010, the Boulder Canyon Hydroelectric Plant Modernization Project has reported the following jobs created or retained as a result of federal funding:

Fiscal Quarter Number of Jobs Created or Preserved

2010, Quarter 1 (January - March 2010)


2010, Quarter 2 (April - June 2010)


2010, Quarter 3 (July – September 2010)


2010, Quarter 4 (October – December 2010)


2011, Quarter 1 (January - March 2011)


2011, Quarter 2 (April - June 2011)


2011, Quarter 3 (July - September 2011)


2011, Quarter 4 (October - December 2011)


2012, Quarter 1 (January - March 2012)


2012, Quarter 2 (April - June 2012)


In addition to the jobs created or preserved through federal funding, the city's share of the total project cost has also contributed to economic recovery. From Jan. 1, 2010 through June 30, 2012, combined consultant and contractor personnel hours paid for by both the city and the federal government have totaled approximately 35,000. This equates roughly to seven people working full time on the project from January 2010 through June 2012. This does not include the hours or jobs created or preserved through subcontractors working on the project.

This project also involved considerable material expenses (steel pipe, a variety of valves, electrical equipment, and the various components of the turbine and generator), which were not accounted for in terms of hours spent on the project. However, the material expenses related to this project did help to create or preserve manufacturing/industrial jobs throughout the United States. As required by ARRA, the various components of the hydroelectric project were substantially manufactured in the U.S.

Major project participants included AECOM (design/engineering), Canyon Hydro (turbine-generator manufacture), Gracon Corporation (general construction contractor), Exponential Engineering Company (electrical engineering) and URS Corporation (historical documentation), as well as numerous other subcontractors, consultants and equipment suppliers.

Plant Modernization Photo Gallery