Hydroelectric Dams: Costs and Alternatives for Restoring Fisheries in the Elwha River

FERC's preliminary cost estimate for the removal of both dams under the most likely option is about $61 million. This cost could increase to about 124.6 million if FERC requires that the large amount of sediment that has accumulated in the reservoirs behind the dams be hauled to a disposal site several miles away rather than stabilized in place. FERC's preliminary cost estimates for constructing fish passage facilities with the dams in place range from $20 million to $40.4 million, depending on the facilities selected. FERC estimated the annual cost of operating and maintaining such facilities at $160,000 to $260,000 ($4.1 million to $6.7 million over a 50-year period). Under both dam removal and dam retention with fish passage facilities, FERC staff believe that new fish hatchery facilities will be needed to restore fish upriver from the dams. FERC estimated that these facilities would cost $3.1 million to construct and $240,000 a year ($2 million over 10 years) to operate. According to FERC, dam removal would provide the best prospects for restoring the fisheries. However, dam removal would result in the loss of nearly 40 percent of a local pulp and paper mill's power that is supplied by the dams' hydroelectric generators. Replacement power could be purchased from the local utility that provides most of the mill's electricity. Although dam retention with mitigation measures would allow the mill to continue using power produced by the dams to meet part of its energy requirements, FERC's analysis showed that the mitigation measures would increase the cost of dam-generated electricity to about the rate charged by the local utility.