Releases to Fluctuate from Reclamation’s Canyon Ferry Dam

Media Contact: Paula A. Holwegner, (406) 247-7300

For Release: September 13, 2011

BILLINGS, MONT. -- Releases from Canyon Ferry Dam will vary on a daily basis for the next several weeks to allow for the continued execution of an ongoing maintenance contract on the spillway. Releases from the dam will be maintained at approximately 3,575 cubic-feet per second (cfs) between the hours of 7 a.m. and 5 p.m., and approximately 4,990 cfs between the hours of 5 p.m. and 7 a.m., starting Tuesday, September 13. This release schedule is expected to continue for several weeks.

Recreationists and residents at Canyon Ferry Reservoir will continue to notice a gradual drop in reservoir elevation, which is normal for this time of year. Although minor, daily fluctuations in water levels between Canyon Ferry Dam and Hauser Dam may be detectable during this period, releases to the Missouri River from Holter Dam are expected to be maintained at the current rate of approximately 4,400 cfs.

Canyon Ferry Dam is a concrete gravity structure approximately 1,000 feet in length along the crest with a structural height of 225 feet. It contains 414,400 cubic yards of concrete. The spillway is an overflow section in the central portion of the dam, controlled by four radial gates. The spillway capacity is 150,000 cfs. The total capacity is 2,051,000 acre-feet at elevation 3,800.00. Four river outlets are in the spillway section of the dam. The maximum discharge capacity of these outlets is 9,500 cfs. One 156-inch-diameter pumping intake pipe is embedded in the concrete of the dam near the left abutment for the Helena Valley Pumping Plant. Three 162-inch-diameter penstock pipes for the power generating units are embedded in the dam near the right abutment. The powerplant is on the right downstream toe of the dam adjacent to the spillway apron. It is of reinforced concrete construction and houses three 16,667-kilowatt vertical-shaft generators driven by 23,500-horsepower turbines.

For additional information, please contact Ms. Paula Holwegner at 406-247-7300.

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Reclamation is the largest wholesale water supplier and the second largest producer of hydroelectric power in the United States, with operations and facilities in the 17 Western States. Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits. Visit our website at and follow us on Twitter @USBR.

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