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DAM REMOVAL 253 Enfield hydroelectric facility on the Penobscot River in Maine. This type of mitigation was unique because it involved dam removal as mitigation for environmental impacts in another river basin. The US Fish and Wildlife Service (FWS) was initially opposed to this mitigation for the proposed West Enfield modifications because it was `out-of-kind' and `out-of-basin'. The mitigation plan was ultimately accepted by the FWS in 1988. The dam removal was successfully completed and Atlantic salmon now have access to Pleasant River, one of Maine's seven wild salmon rivers. Three of the best known currently proposed dam removals in this country are the Savage Rapids Dam on the Rogue River in Oregon, the Edwards Dam on the Kennebec River in Maine and the Elwha and Glines Canyon dams on the Elwha River in Washington. Being 12.2 in tall and 141 in long, Savage Rapids Dam impedes salmon migrations up the Rogue River. It is estimated that it would cost $17 million to rebuild the dam's fish ladders, whereas it would cost $11 million to remove the dam. Environmentalists and natural resource agencies are backing the dam removal alternative. The 6.1 in high and 274 in long rock and timber Edwards Dam on the Kennebec River in Maine has destroyed 27-4km of spawning habitat and blocked movements of Atlantic sturgeon, salmon, striped bass, alewives, blueback herring, brook trout, American shad, rainbow smelt and shortnose sturgeon since it was constructed in 1837. The FERC licence for this dam is up for renewal, and Federal and. State natural resource agencies and environmental groups have endorsed dam removal rather than the dam owner's pro- posed enlargement of hydroelectric generation capacity, raising the dam and installation of fish passage facil- ities. Fisheries biologists with the Maine Department of Marine Resources contend that the dam will have to be removed to restore striped bass, rainbow smelt and sturgeon fisheries in the Kennebec River because these species will not utilize fish passages. After seven years of detailed study by the Federal government, the Elwha River Ecosystem and Fisheries Restoration Act was authorized in October 1992. This legislation called for the study of possible Federal acquisition and removal of the Elwha and Glines Canyon dams on the Elwha River in Washington (Sklar, 1992). The Elwha Dam is a 30.5 in high and 137 in long concrete dam constructed in 1911. The Glines Canyon Dam is a 64m high and 82m crest concrete arch dam constructed further upstream on the Elwha River in 1927. The Glines Canyon Dam lies within Olympic National Park. The Elwha Dam was never required to obtain a hydropower licence, but the Glines Canyon Dam's FERC licence expired in 1976. The 80 km long Elwha River once provided spawning habitat for all five species of Pacific salmon (chi- nook, coho, sockeye, pink and chum) and three species of anadromous trout (steelhead, cutthroat and Dolly Varden char) (Sklar, 1992). Construction of the Elwha Dam 8 km upstream from the mouth of the Elwha River eliminated upstream movement of these species into the temperate rainforest of the Olympic peninsula. After years of study following expiration of the Glines Canyon Dam FERC licence, a draft environmental impact statement (EIS) was issued in 1991 by the FERC, which concluded that restoration of the fisheries was generally poor if the dams were kept, but was generally good if the dams were removed. The draft EIS did not recommend an alternative (FERC, 1991). The Elwha River Ecosystem and Fisheries Restoration Act provided funds for Federal acquisition of the Elwha and Glines Canyon dams, with additional money allocated to the Elwha S'Klallam Indian Tribe for land acquisition along the lower river to compensate for the loss of the salmon guaranteed to the tribe in perpetuity in 1955 (Sklar, 1992). The National Park Service is proposing a major study of the removal of the two dams and restoration of the fisheries on the Elwha River. The estimated cost for removing both dams is $60 million to $124 million. The primary concern regarding removal of these two dams is the fate of the estimated 11.5 x 106 m3 of sediment which has accumulated behind the dams (Stoker and Harbor, 1991). The HEC-6 `scour and deposition in rivers and reservoirs' sediment transport model was utilized to predict sediment movement and deposition characteristics under the dam removal alternative (Stoker and Williams, 1991). A complete EIS of dam removal will be required if removal is authorized, which would include measures to minimize sediment transport during drawdown and following dam removal. Although the likelihood for dam removal is often clearer for small dams posing significant safety hazards, the Savage Rapids, Edwards, Elwha and Glines Canyon dams are significantly more controversial. These much larger dams, and many other large dams up for FERC relicensing, do not pose immediate safety