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Downstream Smolt Passage . To allow downstream emolt passage, the dam was 

 built with six outlet pipes at various elevations so that smolts might locate 

 them at any pool elevation. These open into the tailrace at the foot of the 

 dam. Experiment! (Dunn 1978; LaVoy and Fenton 1979) have shown that this 

 arrangement was killing a number of coho and steelhead smolts. This work also 

 demonstrated delayed migration past the dam and the possibility of mortality 

 in the tailrace. As a remedy, the USACE subsequently constructed a baffle in 

 the tailrace but visual observation indicated no improvement, and the baffle 

 was removed (Dunn, FWS, pers. comm. ) . Costello (1984) wrote that induced 

 mortalities and egression delay were due to failure of the original mitigation 

 measures to (1) account for fish migrational behavior, (2) meet biological and 

 engineering criteria set forth in the multilevel outlet design, and (3) 

 account for circulation and velocity patterns in Wynoochee Lake, especially 

 the forebay. 



Mitigation . Agency attention shifted to further evaluating the effect of the 

 dam on total adult returns (Mathews 1980), culminating in the recommendation 

 by Hiss et al. (1983b) to provide additional mitigation for the equivalent of 

 806 adult coho and 254 adult anadromouB trout annually. 



Interest in resolving mitigation was renewed in 1990 with the transfer of 

 operation and maintenance responsibilities from the USACE to Aberdeen. 

 Aberdeen and Tacotna have been successful at obtaining federal funds of SI. 3 

 million for the additional mitigation. Negotiations are ongoing between the 

 USACE, Tacotna, Aberdeen, WDF, and WDW to determine the best mitigation 

 package. The currently proposed hatchery project is being challenged in the 

 environmental review process. 



Skookuachuck Daa 



Skookumchuck Dam was built in 1970 and is managed by Pacific Power and Light 

 Company (PP£L) of Portland, Oregon. The project provides water for two coal- 

 fired power plants south of Bucoda. The dam can store up to 35,000 acre-feet 

 (Mahlum 1976), and maintains summer flows, of which up to 30 cfs have been 

 diverted at Mile 7.8 and pumped to the plants. The diverted water is turned 

 into steam at the power plant, and not returned to the river. 



Dam construction permanently inundated approximately two miles of former 

 spawning habitat, and, since it has no fish ladder, blocked access to 12 

 additional miles of spring Chinook, fall Chinook, coho and steelhead spawning 

 area above the reservoir (Hiss st ai. 1982). This resulted in an estimated 

 loss of 500 spring chinook, 311 fall Chinook, 1,800 coho (Finn 1973) and about 

 700 steelhead spewners (WDG 1970). Half the potential coho rearing area (Finn 

 1973) and 90 percent of the potential steelhead spawning grounds on the 

 Skookumchuck were above the dam (PP6L 1979). 



The power company mitigates this loss under agreements with WDF and WDW by: 



- guaranteeing adequate downstream spawning and rearing flow for Chinook, 



- artificially rearing coho, and 



- providing both artificial rearing and fieh passage for steelhead (PPfiL 

 1979). 



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