LIBBY DAM AND LAKE KOOCANUSA KOOTENAI RIVER, MONTANA f ] Draft [ X ] Final Environmental Statement Responsible Office: U.S. Army Engineer District, Seattle, Washington 1. Name of Action: [ X ] Administrative [ ] Legislative 2. Description of Action: The Libby Dam and Lake Koocanusa Project, located in Lincoln County, Montana, is a multiple-purpose project included in the International Water Resource Development Plan of the Columbia River Basin in the United States and Canada. The project was authorized for flood control, at-site power generation, and related water uses by the Flood Control Act of 1950, Public Law 516. Under the provision of a 1964 treaty between Canada and the United States, the project is to commence full storage within seven years after starting construction. Construction on the project started in June 1966 and is scheduled so that the dam will be operational for flood control storage by 30 June 1973. The railroad relocation was completed and in use in November 1970. The Forest Development Road is essentially completed. The reservoir bridge and approach roads are essentially completed. 3. a. Environmental Impacts: This project will provide: protection to the downstream Kootenai River flood plain from spring floods, and, together with Canadian storage and existing storage in Columbia Basin, will provide additional flood protection to the Lower Columbia River flood plain; 854,000 kw of firm power initially to the Pacific Northwest power system; about 13,000 acres for public recreation use. About 300 people will have to relocate in the United States portion of the project. Material cleared for construction and from the reservoir area is disposed of by burning and burying. Construction activities have not had a significant impact on water quality. A selective with­ drawal system is being installed to control the water quality of down­ stream releases. A reregulating dam will be constructed when the addi­ tional units are installed at Libby Dam to regulate peaking flows. Population increases due to construction activities have had an effect on the economy and public schools in the project area. b. Adverse Environmental Effects: Completion of the dam will per­ manently impound the free flow of the river and alter fish and wildlife habitat in the area. Stream habitat improvement measures and a barrier dam to block non-game fish intrusion are in progress on one tributary and are being planned or programmed for other tributaries of Lake Koocanusa. The Corps of Engineers will provide funds to the State of Montana for construction of a hatchery to produce game fish with which to stock project associated waters. Important wildlife winter range will be inundated by Lake Koocanusa. Relocation of the Forest Development Road and Montana State Highway 37 will further reduce available wildlife habitat and hamper wildlife movements. Relocation of the Burlington-Northern mainline caused an additional loss of wildlife habitat. As partial mitigation for lost wildlife habitat, the Forest Service is carrying out a habitat improvement program on about 7,000 acres of National Forest land. Acquisition, in fee or by easements, of private land to be developed as replacement wildlife habitat is also being considered; however, Congressional authorization may be required. Channel changes required by the relocation of Burlington-Northern resulted in shortening the stream channel in the Fisher River, Wolf Creek and Fortine Creek by about 2 miles. A total of 140 rock groins were placed in these channel changes to assist and expedite the redevelopment of fish habitat in the new channel and pre­ vent degradation of the remaining natural channel. New meandering channels were created in one section of Wolf Creek. Alternatives: At this time, the only alternatives, other than possible design changes, would be to abandon the project or finish con­ struction to a lesser extent than authorized. Alternative methods of debris disposal are being studied. The alternative of adding power to the reregulating dam is being studied; however Congressional authori­ zation would be required for the addition of power to the reregulating dam. An alternate route for Montana State Highway 37 to lessen its environmental impact was proposed by the Montana Department of Fish and Game but additional consideration by the State's Natural Resources Advisory Council concluded that the proposed route should be developed. The Governor of Montana concurred with this conclusion. 5. Written Comments Received: Bonneville Power Administration Soil Conservation Service Bureau of Sport Fisheries and Wildlife Department of Health, Education and Welfare Bureau of Outdoor Recreation Federal Power Commission National Park Service Montana Department of Fish and Game Bureau of Reclamation Montana Department of Health U.S. Coast Guard Montana Department of Highways Federal Highway Administration Montana Water Resource Board National Marine Fisheries Service Idaho Department of Fish and Game Forest Service Idhao Water Resource Board Town of Rexford 6. Draft Statement to CEQ: 24 June 1971 Final Statement to CEQ: £ § 1972. Environmental Statement Libby Dam and Lake Koocanusa Kootenai River, Montana Prepared by U. S. Army Corps of Engineers District Seattle, Washington Libby Dam and Lake Koocanusa will be located on the Kootenai River m northwest Montana (inclosure 1). The damsite is 219 miles upstream from the confluence of the Kootenai and Columbia Rivers and about 17 miles upstream from the town of Libby, Montana. This is a multiple- purpose project included in the International Water Resource Develop­ ment Plan of the Columbia River Basin in the United States and Canada. The project is authorized for flood control, at-site power generation, and related water uses by the Flood Control Act of 1950, Public Law 516 • Lake Koocanusa ^ill extend into British Columbia, Canada. Under the provisions of a 1964 treaty between Canada and the United States, the project is to commence full storage within 7 years after starting construction. Project construction was initiated in June 1966 and is scheduled so that the dam will be operational for flood control storage by 30 June 1973. Lake Koocanusa, at normal full pool elevation 2,459 feet, will have a surface area of 46,500 acres (28,850 in the United States and 17,650 in Canada) and 4,965,000 acre-feet of usable storage. The lake will have a shoreline of 229 miles (117 in United States and 107 in Canada) and length of 90 miles (48 in United States and 42 in Canada). The treaty also provides that Canada has responsi­ bility for project development and impacts where the lake extends into British Columbia. Libby Dam will rise about 446 feet above bedrock, be 3,055 feet long and will include a powerhouse on the west (right) bank with four 105,000 kw generators initially and provisions for four additional units to be installed later. A visitor center building currently being used as the construction office, and an observation overlook have been constructed on the west bank. Initial pool raising to the spillway crest, elevation 2405, will begin in May 1972. Full storage will occur in June or July 1973 if sufficient water is available. Riverflow is presently diverted through a low diversion opening left in the dam. Overall project construction is about 64 percent complete as of July 1971. The dam construction is 86 percent complete with a total of 3,325,695 cubic yards of concrete having been placed as of 11 August 1971. The schedule for concrete placement is shown on the attached chart (inclosure 2). Powerhouse construction is scheduled to begin in 1972 and the first four generating units will be on line in 1976. A selective withdrawal structure will be constructed to control the release of water through the turbines to improve the capability of adhering to interstate water quality standards. The system will permit control of the downstream water quality by generally selecting the reservoir level from which water is withdrawn. Mainline tracks of the Burlington-Northern Railroad north to Jennings, Montana, and within the future Lake Koocanusa were relocated to a completely new 60-mile route between Stryker, Montana, and Jennings, Montana, starting near the confluence of the Fisher and Kootenai Rivers, about 3 miles downstream from Libby Dam. Railroad relocation work was completed in October 1970 and the new line went into service on 1 November 1970. The new Burlington-Northern route is shown on inclosure 3. The existing Montana State Highway 37, now located on the west bank of the Kootenai River, will be relocated on the east bank. A Forest Development Road is being constructed along the west bank. The two roads will be connected by bridges, one crossing the Kootenai River 3 miles downstream of Libby Dam and one crossing Lake Koocanusa about 32 miles upstream of the dam. Montana State Highway 37 is about 27 percent completed and the Forest Development Road is about 96 percent completed. The Forest Development Road from the mouth of the Fisher River to the Lake Koocanusa Bridge, scheduled for completion in late 1971, will be used as a substitute Montana State Highway until the new highway is completed in 1975. Lake Koocanusa Bridge was completed in November 1970 except for painting and road surfacing. The highway and road relocations are shown on inclosure 4. All of the trees and large shrubs above elevation 2,282 feet will be cleared from the reservoir before filling. In addition, most of the stumps between elevations 2439 and 2462 will be removed to enhance recreational use of the lake. Clearing work was about 90 percent complete as of August 1971 and is scheduled to be completed prior to May 1972. The town of Rexford will be relocated to a new townsite just upstream of the present town. The City Hall-Fire Station was completed in June 1971. Completion of New Rexford School is scheduled for November 1971.