Dedicated on August 24, 1975, Libby Dam spans the Kootenai River 17 miles upstream from the town of Libby, Montana. The reservoir behind the dam is Lake Koocanusa; it extends 90 miles upriver from the dam and has a maximum depth of about 370 feet. Forty-two miles of the lake are in British Columbia, Canada. The Kootenai River is the third largest tributary to the Columbia river, contributing almost 20% of the total water in the lower Columbia.
The dam is operated by the Seattle District of the United States Army Corps of Engineers. The Libby Dam Project is a multi-purpose water resource development. Its purposes are flood reduction, hydro-power, recreation, and environmental stewardship. At full capacity, the dam can pass over 160,000 cubic feet per second of water. The dam is designed with a selective withdrawal system that allows water passage from various levels of Lake Koocanusa. This allows the dam operators to moderate water temperatures downstream. The river continues past Bonners Ferry, Idaho to Kootenay Lake and joins the Columbia River.
Libby Dam’s powerhouse electrical distribution equipment contains five turbines and is capable of generating 600 megawatts. The electricity is managed by the Bonneville Power Administration and services eight states: Montana, Idaho, Washington, Wyoming, California, Utah, Oregon and Nevada. The money earned from electricity sales goes to the United States Treasury to repay the cost of building and operating Libby Dam.
In July 2014, the U.S. Army Corps of Engineers sought firms capable of replacing the aging dam and powerhouse electrical distribution equipment. Pick Electric Inc. of Spokane, Washington, was awarded the $6,537,098 fixed-price contract, of which they sub-contracted the electrical distribution panels out to ControlFreek Inc.
In both the dam and powerhouse configurations, CFI utilized Allen-Bradley’s Bulletin 1756 ControlLogix® I/O modules to provide a full range of digital, diagnostic digital, analog, motion control, and specialty I/O for specific application needs. The I/O modules in the chassis were linked to controllers across an Ethernet network.