Electrical Power for Valdez and the Copper River Basin-1981

It is our intent to protect the existing salmon runs of AllisonCreek. Should we be unsuccessful in adequately protecting.thoseresources, other mitigation measures such as providing artificialhatching, spawning, and/or rearing areas may be· determined necessary.A final analysis to determine whether or not any of these mitigationmeasures would be acceptable or are favored cannot be made with datanow available.· However, based upon present flow and temperaturedata, we have tenatively determined that excess flows from thepowerhouse should be discharged directly to Port Valdez to mitigatepotential adverse impacts to fish resources.Additional data needs which have been identified should be satisfiedas soon as possible. Those studies are: a comprehensive analysisof the pre- and post-project temperature regimes, salmon escapementsurveys, bald eagle nest surveys, and an instream flow assessment.These studies should be conducted cooperatively by the FWS and CEoExecution of these studies would satisfy data needs for refinement/development of mitigation recommendations and provide data neededfor preparation of a supplement to this report. A cooperative studythrough project construction and operation would allow furtherrefinement of mitigation recommendations, assessment of the accuracyand effectiveness of these recommendations, and provide baselinedata for use in the planning of similar projects in the future. Anamended scope of work and associated transfer of funds to the FWSwould be required.RECOMMENDATIONS1. That the design of the powerhouse allow the release ofregulated flows to Allison Creek through the tailrace andexcess flows to Port Valdez through the other tailrace.2. That flows from the powerhouse tailrace to Port Valdez bedischarged subtidally to at least -10 feet MLLW from Junethrough September.3. That the proposed start-up of project operation affectingthe natural flows in Allison Creek occur in an even year.4. That the timing of proposed construction activities in oron the banks of Allison Creek be coordinated with the FWS,NMFS,and the ADF&G.5. That streambanks be restored to pre-project integrityduring the construction season in which they are damagedand debris or vegetation be kept out of streams.6. That any structures placed in or across streams be removedduring the same construction season.7. That clearing for the penstock construction be limited tolarge shrubs and any trees which may be encountered.