Electrical Power for Valdez and the Copper River Basin-1981

Allison Lake limnology is similar to Bradley Lake near Homer and CraterLaKe near Juneau, water Deing drawn through the lake tap would beapproximately 7°C. Due to the lack of data, the worse case basis wasused. Prior to any construction, temperatures would be determined andmeasures to prevent less than optimal temperatures would be employed, ifnecessary.Without mitigative measures, major adverse impacts to the fishery areexpected to occur. If the change in water temperature causes acceleratedegg incubation and early fry emergence, there is a high probability thatthe majority of the salmon run would be destroyed. Environmental studiesto fill the data gaps associated with the impacts on the salmon resourceshave been scheduled for the advanced engineering and design phase. Thestudy would begin prior to construction, monitor the effects duringconstruction, and assess the impacts of the project on the fisheryresource of Allison Creek. The proposed stUdy would collect backgroundinformation on numbers and species of spawning fish, hatching time withregard to water temperature and the effects of saltwater flooding toincubation time. The study would provide specific information on theeffects of a hydroelectric project on Allison Creek and would alsoprovide general information on the effects of hydroelectric projects onshort coastal streams throughout Alaska. The information would beutilized in future hydroelectric planning processes to assureenvironmentally sound projects.Determining a monetary value for the Allison Creek fishery appears to beinfeasible. Population estimates for Allison Creek were not scheduledand counts were made on a time-available basis. Tne counts were not madedaily during the entire run and the estimates must De considered as theleast number of spawning adults.Commercial fishing catches show only a small portion of the value of asalmon run. Based on research statistics for this region of Alaska andusing the highest number of spawning chum salmon (2,660) with half beingfemales (1,130), approximately 3,657,500 eggs are deposited. Mortalityis high and approximately 75 percent of the eggs either do not hatch orthe fry never migrate to the ocean. Successful fry may number in excessof 900,000 individuals. To maintain the species, at least 2,660 fishwill return to spawn, or 0.3 percent of the successful fry. For astatewide average, commercial catches equal escapement or 2,660 fish.This leaves over 909,175 fish which enter the food web. The exact amountof biomass added to the next trophic level is unknown but is considerablymore than that taken in the commercial harvest.Other nonquantifiable values are the contribution to the sports fishery,esthetic values, and the contribution to the human nonconsumptiveknowledge of the natural environment.EIS-16