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Home My WebLink AboutAPA1775Anch "r FEDIRAL ENERGV REGULATt'RV COMMISSION PROJECT No.1114 SUSITNA HYDROELECTRIC PROJECT ~cn=(0 ~.- =~ALASKA POWER AUTHORITY ~ '"0~;Eg COMMENTS =LD ==--oLD E~ON THE =-==M~ FEDERAL ENERGY REGULATORY COMMISSION DRAFT ENVIRONMENTAL IMPACT STATEMENT OF MAY 1984 1'7 VOLUME 4 APPENDIX 1I- EV ALUA TION OF NON-SUSITNA HYDROELECTRIC ALTERNA TIVES AuaUST 188.. DOCUMF.NT No.1775 ~_-ALASKA POWER AUTHORITY -.. AppendixII-EvaluationofNon-SusitnaHydroelectricAlternativesARLIS.AlaskaR.LIbrary&.InfoesoUTcesAncho.'1lnatlOnServIces1:age~AlaskaLen(0..-I"-(0('I)ooo1.01.0I"-('I)('I)...FEDERALENERGYREGULATORYCOMMISSIONSUSITNAHYDROELECTRICPROJECTPROJECTNO.7114ALASKAPOWERAUTHORITYCOMMENTSONTHEFEDERALENERGYREGULATORYCOMMISSIONDRAFTENVIRONMENTALIMPACTSTATEMENTOFMAY1984Volume4August1984SusitnaFileNo.6.4.6.:-r~14~5"~$3~~1-by\.D..1115" TableofContentsSectionTitle'1JSummaryS-l1.02.0IntroductionPurposeandScope1-12-13.04.0PreviousStudiesEvaluationMethodology3-14-15-15-15-15-45-65-85-115-135-156-16-16-16-16-36-46-46-66-76-76-9ARLIS1..,AlaskaR.lbrary&1.4':.esoUTces•n-.to1lllatJonSAnchorage,Alaskaet"VJcesi6.1.3.1General6.1.3.2Dam6.1.2.1General6.1.2.2Dam6.1.2BrowneDamandReservoir6.1.3KeetnaDamandReservoir5.0DescriptionofProjects5.1General5.2JohnsonDamandReservoir5.3BrowneDamandReservoir5.4KeetnaDamanaReservoir5.5SnowDamandReservoir5.6ChakachamnaDamandReservoir5.7WatanaDamandReservoir5.8DevilCanyonDamandReservoir6.0EngineeringAssessmentofAlternativeSites6.1SiteAssessment6.1.1JohnsonDamandReservoir6.1.1.1General6.1.1.2Dam453410/TOC840820JJJJJJ ]TableofContents(Conld)SectionTitle6.1.4SnowDarnandReservoir6.1.4.1General6.1.4.2Darn6.1.5ChakachamnaDarnandReservoir6.1.5.1General6.1.5.2Darn6.1.5.3ProjectRisk6.1.6WatanaDarnandReservoir6.1.6.1General6.1.6•2Darn6.1.7DevilCanyonDarnandReservoir6.1.7.1General6.1.7.2Darn6.2ComparisonofNon-SusitnaAlternativeProjectswiththeProposedProject6.2.1SummaryandConclusions6.2.2Comparisons6.2.3TransmissionLines7.0EnvironmentalEvaluationofAlternativeSites7.1Background7.2SiteAnalysis7.2.1Johnsonsite7.2~1.1SocialSciences7.2.1.2TerrestrialResources7.2.1.3AquaticResources7.2.2BrowneSite7.2.2.1SocialSciences7.2.2.2TerrestrialResources7.2.2.3AquaticResources6-106-106-126-136-136-146-166-206-206-226-236-236-246-256-256-266-287-17-17-17-17-17-77-10·7-127-127-167-18j11 1-1I1]SectionTableofContents<Con't)Title7.2.3KeetnaSite7.2.3.1SocialSciences7.2.3.2TerrestrialResources7.2.3.3AquaticResources7.2.4SnowSite7.2.4.1SocialSciences7.2.4.2TerrestrialResources7.2.4.3AquaticResources7.2.5ChakachamnaSite7.2.5.1SocialSciences7.2.5.2TerrestrialResources7.2.5.3AquaticResources7.3ComparisonofHydroAlternativeswiththeProposedProject7.3.1SocialSciences7.3.2TerrestrialResources7.3.3Aquar1cResources7-197-197-227-257-267-267-307-327-337-337-387-417-437-437-477-498.0CostComparison-AlternativeSitesvs.ProposedProject8-18.1Introduction8-·18.2DEIS1982LevelCostDevelopment8-18.3DevelopmentofaCommonEscalationFactor8-38.4AdditionalCostofTransmissionIntertie8-38.5Conclusions8-3J9.0PowerandEnergyProduction9.1Introduction9.2HistoricStreamflowRecord9.3MinimumFlowinSummer9.4EnergyProductionintheSummer9-19-19-29-29-3IJiii TableofContents(Can't)SectionTitle9.5MonthlyDistributionofEnergy9.6DependableCapacity9.7Conclusions10.0References9-39-59-610-1453410/TOC8408201V 1IJ1_JIJTablesTableTitle1.EngineeringAssessment-Alternativesvs.Susitna2.ComparisonofLandAreaImpacted3.1982Summary-EstimatedChakachamnaSalmonEscapementbyWaterbodyandDrainage4.ComparisonofSocioeconomicResourcesandImpactsAmongNon-SusitnaHydroAlternativesandtheSusitnaProject.5.ComparisonofLand-UseResourcesandImpactsAmongNon-SusitnaHydroAlternativesandtheSusitnaProjeGt.6.ComparisonofCulturalResourcesandImpactsAmongNon-SusitnaHydroAlternativesandtheSusitnaProject.7.ComparisonofRecreationalResourcesandImpactsAmongNon-SusitnaHydroAlternativesandtheSusitnaProject.8.ComparisonofAesthetics/VisualResourcesandImpactsAmongNon-SusitnaHydroAlternativesandtheSusitnaProject.9.ComparisonofTerrestrialResourcesandImpactsAmongNon-SusitnaHydroAlternativesandtheSusitnaProject.10.ComparisonofAquaticResourcesandImpactsAmongNon-SusitnaAlternativesandtheSus'itnaEroject.453410/EXB840820v ..~]Tables(Could)TableTitle11.DevelopmentofJanuary1982LevelHydroelectricCosts.12.ComparisonofIndividualHydroelectricAlternatives.13.Alternativesvs.Susitna,January1982LevelFigures.14.BasicDataforFiveAlternativeSitesandtheProposedProject.15.AlternativeHydroProjects,MonthlyAverageFlowsandMinimumReleaseinSummer.IJJ16.17.18.19.20.21.22.AlternativeHydroMinimumSummerCapacity~nDEIS.AlternativeHydroHydrauiicCapacity,ComputedfromInstalledCapacityinDEIS.AlternativeHydroEnergyProduction(GWh)-Year2010LoadConditions.AlternativeHydroEnergyProduction(GWh)-Year2010LoadConditions.AlternativeHydroEnergyProduction(GWh)-Year2010LoadCondition.ComparisonofAlternativeHydroEnergyProduction(GWh)-Year2010LoadConditions.AlternativeHydroDependableCapacitybySimulationwithRESOP.]_J4534l0/EXB840820v~ ]1J]]1jExhibitNo.12345678453410/EXB840820ExhibitsTitleAlternativeHydroelectricProjectsLocationPlanTransmissionLinePlanJohnsonDamandReservoirPlanBrowneDamandReservoirPlanKeetnaDamandReservoirPlanSnowDamand.ReservoirPlanChakachamnaDamandReservoirPlanSusitnaProjectDamsandReservoirsPlanV11 lI]]JSummaryAsapartofthedevelopmentoftheSusitnaHydroelectricProject(ProposedProject),theAlaskaPowerAuthority(PowerAuthority)examinednumerouspotentialhydroelectricsitestodeterminewhichsitesmightbestfulfilltheenergyneedsoftheRailbeltRegion.Followingascreeningprocessbasedonenvironmental,economic,andengineeringconsiderations,thePowerAuthorityconcludedthatdevelopmentoftheSusitnaproject,includingboththeWatanaandDevilCanyonsites,bestservedtheenergyneedsofthestate.ThisconclusionwasreachedbyseveralFederalagenciesinsimilarscreeningstudies(AlaskaPowerAuthorit~1983a;AlaskaPowerAdministration1980).Therefore,thePowerAuthorityproceededwiththerequisitemoredetailedstudiesandsubmittedaLicenseApplicationtotheFederalEnergyRegulatoryCommission(FERC)inFebruary1983.ArevisedLicenseApplicationwassubmittedinJuly1983.TheFERCStaffconcluded1nits·May1984DraftEnvironmentalImpactStatement(DEIS)that"basedonconsiderationsofengineeringfeasibility,economiccharacteristics,andenvironmentalimpacts•••amixedthermal-basedgenerationscenario,withselectednon-Susitnahydropowerprojectsaddedasneeded,appearstobethemosteffectiveapproachtomeetingtheprojectedgenerationrequirementsoftheRailbelt..area."TheDEISstatedthatacombinationoffivespecifichydroelectricsites-Johnsonsite(210MW)ontheTananaRiver,Brownesite(100MW)ontheNenanaRiver,Keetnasite(100MW)ontheTalkeetnaRiver,SnowSite(100MW)nearKenaiLake,andtheChakachamnasite(300MW)onChakachamnaLake-shouldbeusedtopartiallyfulfilltheenergyneedsoftheRailbelt(FERC1984).ThePowerAuthor.itystronglydisagreesthatthecombinednon-Susitnahydroandthermalgenerationscenario1Sthemosteffectiveapproachfromanengineering,econom1C,orenvironmental·perspectivebywhichtomeettheenergyneedsofthestate.453410840820S-l Thisreportspecificallyaddressesandre-eva1uatestheFERCrecommendednon-~usitnahydroalternativesfromengineering,economicandenvironmentalalternatives1SpresentedasAppendixIIIofthisdocument.TofullyconsiderthetotalimpactsfromtheFERCcombinedhydro-thermalscenario,thetotalimpactsfromthethermalprojectsmustbeaddedtothesumtotalofhydroimpacts.~l,Jperspectives.AseparatereportthatspecificallyaddressesthethermalThisreportillustratesthatwhencomparisonsaremadebetweenthe.non-SusitnahydroalternativesandtheProposedProject,certainkeyengineeringandenvironmentalaspectsofthealternativesmakethemmuchlessfavorable]thantheProposedProject.nativesarediscussedbelow.JohnsonSiteEngineering;Thekeyproblemsassociatedwiththea1ter-J]1J1.2.Extensiverelocationsofexistingcommunities,theAlaskaHighway,andacurrentlyinactivepetroleumpipelinewouldberequired.Thiscouldrequirefrom24to36months.Thissitewouldbesusceptibletosedimentationandthedevelop-mentofextensivemudflatsthatwouldresult1nloststoragecapacityandthereforewinterenergygeneration.respecttoJ3.ThissiteFairbanks1SremotelyTransmissionlocatedwithIntertie.ToconnecttheAnchorage-thesitewithJJ453410J840820Fairbankswouldrequireapproximately'135milesoftransmissionlineatacostofapproximately$4,650,000.Approximately1640acresoflandwouldbeaffectedbytheinstallation.ofthetransmissionline.S-2 8-3Environmental:facilitieswouldmateriallyaddtothecostofsitedevelopment.5.ThesitewouldprobablyrequireincorporationoffishpassageThesefacilitieswhicharenotalwayseffective(Bell1980).4.Therewouldbedifficultiesinobtainingsufficientimperviousborrowmaterials,andextensivefoundationexcavationsmightberequired.2.Approximately23milesoftheAlaskaHighway,themajoroverlandroutebetweenAlaskaandthelower48,wouldneedtoberelocated.Therelocatedsectionwouldbeco'nsiderablylonger(approximately33miles).3.Anabove-groundpetroleumpipelinewouldhavetoberelocated.Thiswouldentailmovingthepipelinefromafairlydirectrouteandlevelgradienttoonethattraversessteepterrainandwouldbelessdirect.1.Twocommunities,DotLakeandTheLivingWord,withpopulationsofapproximately70and200personsrespectively,wouldneedtoberelocatedbecausetheyarewithintheimpoundmentzone.Constructionandoperationwould,affecttheinfrastructureofDeltaJunctionandTok.1j~j'1~J~]'J'J]J]J1J1.J~J]__JJJ453410840820 Cj4.5.Thesurfaceareaofthisimpoundmentalone(94,500acres)wouldbefarlargerthanthatfortheProposedProject(45,800acres)andthuswouldinundategreaterexistinghabitat.Theprojectwouldinundatehuntingandfishingsites1nanextensivewildernessarea.6.Fourperegrinefalconnestlocationsoccuralongtheshorelineoftheproposedimpoundmentzone.Threeofthesewereactive1n1983.Thiswouldmakelicensingoftheprojectverydifficult,ifnotimpossible,becausethisspecies1SclassifiedbytheDepartm~ntofInterior,u.s.FishandWildlifeServiceas"endangered".7.Thefloodplaininthisareaisanimportantwinteringandcalvingareaformooseandcontainsimportantblackbea'randfurbearerhabitat.Lossofthis'habitatwouldsignificantlydecreasethecarryingcapacityoftheareafor,mooseandotherwildlifeandresultinlowerpopulations.8.Anadromoussalmonareknowntoexi~tupstreamofthesite.Thesefisharepredominantlychumsalmon,aspeciesthatwouldnotsuccessfullyutilizepassagefacilitiesandthereforewouldprobablybeeliminatedfromupstreamareas.9.Changes1nflowregimesdownstreamoftheprojectwouldalsoimpactsalmonspawningandhabitat.10.Flowreductions1nthesummercouldseverelydisruptcommercialnavigationontheriver,particularlyinthelowerTanana.IfboththeBrowneandJohnsonsiteweredeve'1oped,thecumulativeimpactofbothprojectsonnavigationdownstreamfromNenanacouldbesignificant.S-4 '1I11.Approximately30,000acresofpalustrinewetlandswouldbeinundated.BrowneSiteEngineering:Environmental:~-)]]]]J4534108408201.2.3.1.2.3.ExtensiverelocationsoftheexistingmajorhighwayroutebetweenFairbanksandAnchorage,theAlaskaRailroad,aGoldenValleyElectricAssociation(GVEA)transmissionline,andseveralhomeswouldberequired.Thiscouldrequireupto48months.Thesitecouldrequiresubstantialfoundationexcavations1nexcessof100feetindepth.Thesitewouldprobablyrequireincorporationoffishpassagefacilities,whicharecostl,yandoftentimesnoteffective.Impactsassociatedwithdevelopmentofthissitewouldincluderelocating8.5milesoftheGeorgeParksHighway,16milesoftheAlaskaRailroad,and16milesofexistingGoldenValley~lectricAssociationtransmissionline.CommunitiesthatwouldbesignificantlyimpactedbyconstructionincludeHealyandNenana.Anadromoussalmonareknowntoexistupstreamofthissite.AswiththeJohnsonsite,oneofthespeciesischumsalmonwhichwouldbeexpectedtobeeliminatedfromupstreamareas.Fishpassagefacilitiesforotherspecieswouldbeneededforthis'site.8-5 '-j4.5.6.Changesinflowregimesdownstreamoftheprojectwouldalsoimpactsalmonspawningandrearinghabitat.TheNenanaRiverisusedforrecreationalrafting.Thiswouldbeeliminatedfromthisreachofriver.Downstreamnavigation,particularlyinthelowerTanana,couldbesignificantlydisruptedbyflowregulationfromthissite(andtheJohnsonsite)•.'Approximately50culturalresourcess~tesareknowntoexistatthissite.significantlydecreasethecarrying.capacityoftheareaformooseandresultinlowermoosepopulations.]].7.Ther1verfloodplain1noverwinteringareafortheimpoundmentmoose.Lossofzone1Sanimportantthishabitatwould-1KeetnaSiteEngineering:J453410840820·1.2.3.Theremaybedifficultyinobtainingsufficientimperviousborrowmaterials,whichwouldrequiredevelo~mentofadditionalon-siteroadsalongsteepslopestogainaccesstohigherelevationswherematerialsmaybeavailable.Inherentstabilityproblemsareassociatedwithexcavationsonsteepslopes.Theonlysuitablelocationoftheconstructioncampsitemaybesubjecttoflooding.Thesitewouldrequireincorporationoffishpassagefacilitieswhichlackproveneffectiveness.8-6 1Environmental:4.ThissectionoftheTalkeetnaRiver(includingDisappointmentCreek)hasbeenrecommendedbytheAlaskaDepartmentofNaturalResourcesasastaterecreationriver.White-waterkayakingintheimpoundmentreachandupstreampassageofriverboatsfromTalkeetna(whichcurrentlyaccessupstreamareasasfarasapproximately2milesaboveIronCreek)wouldbeeliminated.]']]J1.2.3.Highlysignificantrunsofanadromoussalmonexistupstreamoftheproject.Salmonareknowntospawninareaswithinandupstreamoftheimpoundmentzone.Importantimpoundmentzonespawningareaswouldbeeliminated.Inaddition,thereisahighriskthatthechumsalmonrunswouldbeeliminatedaswell.Thehighconcentrationsofsalmon(particularlychinooksalmon)1nPrairieCreek(upstreamofthesite),attractlargenumbers(upto100)ofbrownbearsthatfeedonthesalmon.Thisresource1Sconsideredaseasonallyimportantcriticalhabitatandmaybeimportantformaintainingthecurrentlevelsofbrownbearnumbersinthearea.Changes1nflowregimesdownstreamoftheprojectwouldalsoimpactsalmonspawningandrearinghabitat.'1j5.Mooseutilizetheproposedimpoundmentzoneyear-roundandconcentrateinthefloodpiainduringthefallandwinter.Lossofthishabitatwoulddecreasethecarryingcapacityoftheareaformooseandresultinlowermoosepopulations.6.Theprojectcould'significantlyimpactbaldeaglesandothernestingraptorseitherthroughlossofnestingsitesorareductioninpreybase.453410S-7840820 SnowSiteEngineering:']]]1.2.Thissitewouldrequireupgradingapproximately83milesofexistingtransmissionlinebetweentheprojectareaandAnchorageatacostofapproximately$1,400,000.A4-mi1elongtransmission11nestubwouldberequiredfromthepowerhousesubstationtothisexistingtransmissionfacility.Thesiteissubjectedtoglacialoutburstfloodingeverytwotothreeyears.Thiswouldentailveryhigbcostsforspecialdesigntreatment1nthewayofincreasedprojectfreeboard,increasedspillwaycapacityoremergencyspillways,orareducedoperatingpoollevel.Environmental:]Cl]4534108408201.i.3.4.Theprojectwouldinundatehuntingandfishingareasinawildernessvalley;·anexistingrecreationalfishery1nLowerParadiseLakewouldbeeliminated.Changes1nflowregimesdownstreamoftheprojectcouldimpactsalmonspawningandrearinghabitatintheKenaiRiver.Riparianareaswithintheimpoundmentzonewouldbeeliminated.Thisisimportanthabitattomooseandotherwildlife.Lossofthishabitatwoulddecreasethecarryingcapacityoftheareaformooseandresultinlowermoosepopulations.Viewsofthedam,transmissionlinesandotherfacilitieswouldbehighlyvisibletorecreationistsintheSouthForkvalleyandtosightseersonthehighwayandrailroad.S-8 ChakachamnaSiteEngineering:'1]]J]]]-JJ4534108408201.2.3.4.5.6.Thepowertunnel,whichisapproximately10mileslong,willrequireverydetailedgeologicinvestigationandstudybecauseofitsgreatersusceptibilitytoproblemscreatedbychangesingeologyalongitslength.Highin-siturockstressesmayoccurneartheundergroundpowerhouseduetothenearbypresenceoftheLakeClark-CastleMountainfault.Thesestresseswillcausesignificantdesignandconstructionproblemswhichwillbecostlyandtimeconsuming.ThenearbypresenceofBarrier,Blockade,andMcArthurGlacierscouldmakelakelevelprediction,andtheresultingregulatio.nofstorageforpowerregulation,uncertain;couldcauseout~urstfloodingwhichaffectsthedesignandcostofprojectfeatures;andcouldendangerthetailracechannelandportalsofthetailracetunnelandaccesstunneltotheundergroundpowerhouse.AlargeeruptionofMt.SpurrVolcanolocatedabout7milesfromtheoutletofChakachamnaLakecouldinundatetheproposedpowerintakesitewithvolcanicash,ortriggeralargelandslideormudflowwhichwouldburyboththeupstreamanddownstreamendsofthefishpassagefacilities,dam,spillway,andpowerintakestructure.Thesitelieswithinazoneofhighse1sm1Crisk.This·site1SremotelylocatedwithrespecttotheAnchorage-FairbanksIntertieandwouldrequireanextensivetransmissionline(approximately130milesinlengthand1200acresofcorridor.S-9 Environmental:8-108.Improvementstoexistingaccessfacilitiescouldtakeupto48months.7..Inadditiontonewaccessrequirements,extensiveimprovementtoexistingroadsandtransportationfacilities(e.g.,Tyonekdockfacilities)wouldbenecessary.Intotal,thenumberChakachatnaRiverorintheMcArthurRiver.9.Thesitewouldrequireincorporationofpotentiallyineffectivefishpassagefacilitiesforbothupstreamanddownstreammigratingfishinvolvinga930footlongapproachchannel,anda300footlongtunnelconnectingthedownstreamdischargefacilities.ofadultsalmonthatcouldbesignificantlyaffected1Sover100,000.TheseimpactsmaybeduetoeitherfishpassagedifficultiesordiversionofflowfromtheChakachatnaRivertotheMcArthurRiverwhichcouldresultinmiscueingformigration,changesinspawninghabita·tresultingfromflowchange,ordelaysinmigration.2.Changesinflowbydiversioncouldalsosignificantlyaffectfishrearinghabitat,particularlyinareas,suchasNoauktaSloughontheChakachatnaRiver'>thatareknownrearingareas.3.TheprojectwouldadverselyaffectbrownbearuseofsalmonspawningareasontheChilliganandChakachatnar1vers.StabilizationofriverandsloughbanksduetoreducedflowofwaterdowntheChakachatnaRiverwouldhaveeventual,long-termimpactsonmooseandfurbearers.1.Thereisapotentiallossofasignificantsockeyesalmonrun(upto40,000fish)upstreamofthesite,andimpactstoapproximately64,000additionaladultseitherdownstreamofthedamsiteonthe]JCj~~J-1--]~J]]~-J~JCJJJ-1J]J]J453410840820c1 )Thedecreaseinr1verflowwouldalsoresult1ndewateringofareasusedasnestinghabitatbywaterfowl.Non-8usitnaHydroelectricAlternativesvs.ProposedProjectComparedtotheProposedProject,thenon-Susitnahydroelectricalternativeswould:1.impactmanymorecommunitiesduringconstructionandoperation;2.requiremorerelocationofexistingcommunities,highways,railroads,andtransmissionlines(virtuallynonewouldberequiredfortheProposedProject);3.result1ninundationand/ordisturbanceoffarmoreacreageresultinginmoreextensivewildlifeimpacts;JJ4.5.6.7.placeasignificantnumberofanadromoussalmonrunsathighriskandresultinpossibleeliminationofmanyfishpermanently;eliminateexistingfree-flowingriversthatarenowextensivelyused,someofwhicharerecommendedasstaterecreationrivers;Disruptimportantnavigation,particularlyonthelowerTananaRiverandperhapsontheYukonRiver;anddirectlyimpactfournestinglocationsofanendangeredspecies,theperegrinefalcon,attheJohnsonsite(theProposedProjectwillnotimpactanyendangeredspecies)._1Information1nthisAppendixshowsthateachsitewouldhave.potentialenvironmentalimpacts,engineeringproblems,orunfavorableprojectcoststhatoftenexceedthoseoftheProposedProject.4534108408208-11 II--jWhenthesumtotalofimpacts1.Sconsidered,itisclearthatthecombinednon-Susitnahydroalternativesscenarioisnotaviableoption,particularlywhenit1.SnotedthatthepowerproducedwillonlypartiallyfulfillthetheRailbelt'stotalenergyneeds.Addingthermalunitstomeetthoseneedswouldonlycompoundtheenvironmentalimpacts.Thefeasibilityofthiscombinedhydro-thermalscenariobecomesevenmoretenuouswiththedifficulties,bothtechnicalandsociopolitical,ofsitingcoal-firedthermalunitsnearthevisuallysensitive,ClassIairqualityareaofDenaliNationalParkandPreserve.TheProposedProjectwouldmeetmoreoftheenergyneedsoftheRailbeltwithfarfeweradverse~mpacts.TheinformationandconclusionsreachedinthisreportshouldbeusefultotheFERCStaffinreconsideringitsrecommendationconcerningthecombinednon-Susitnahydro-thermalgenerationscenario.Inadditiontoengineeringandenvironmentalconsiderations,thisAppendixdiscussescostcomparisons(Section8.0),primarilybecauseitisnecessarytoclarifytheuseageofcostestimatesinpreviousstudiesandbytheFERCintheDEIS.Whencostsarebasedonaconsistentanalysis,theProposedProject'scostperunitofinstalledcapacityissignificantlylowerthanforthehydroalternatives.Powerandenergycomparisonsofthealternatives,asdescribedbyFERCStaffintheDEIS,havebeenreexaminedbytnePowerAuthority(Section9.0).Thisreexaminationshowsthat,undertheflowregimespresentedintheDEIS,theseasonalregulationofflowsbythealternativereservoirswouldbeverylimitedbythehighminimumflowrequirementsinthesummer.Alargeamountofenergywouldbespilledintheinitialyearsofthealternativeprojects'operationsbecauseoflowenergydemandandhighflowrequirementsinthesummer.ItisonlywhenRailbeltenergyrequirementsincreasewithtimethatmoresummerenergycanbeused.1J453410840820S-12 I]ClCj]J1.0IntroductionTheAlaskaPowerAuthority(PowerAuthority)concluded1nitsFERCLicense.ApplicationthattheSusitnaHydroelectricProject(ProposedProject),includingboththeWatanaandDevilCanyondamswasthebestalternativecapableofmeetingtheenergydemandsoftheRailbeltregion.ThisconclusionwasreachedbasedonstudiesofupperSusitnaBasinpotentialhydroelectricalternativesites,non-Susitnahydroelectricalternatives,andothernon-hydrodevelopments.ThisAppendixaddressesconclusionspresentedintheFERCISDraftEnvironmentalImpactStatement(DEIS)whichstatedapreferenceforalternativepowergenerationscenarios(FERC1984).ThepreferredalternativeidentifiedintheDEISconsistsofcombinedhydro-thermalfacilitiesincludinghydropowerfacilitiesatsitesoutsidetheSustinaBasinplusvariouscoalandgas-firedthermalunits.ThehydroelectricsitesrecommendedwereJohnson,Browne,Keetna,SnowandChakachamna.J453410/18408201-1 1I']]]J2.0PurposeandScopeThepurposeofthisAppendixJ.StoevaluatetheengineeringandenvironmentalfeasibilityofthealternativehydroelectricdamsitesidentifiedbytheFERCStaffinitsDEIS.ThisAppendixdescribesandevaluatesthegeneralarrangementdevelopedforeachofthepotentialalternativesites.ThesestudieshaveessentiallyfollowedtheplanformulationandmethodologyoutlinedJ.ntheFERCLicenseApplication,ExhibitB(AlaskaPowerAuthority1983a,1983b,1983c).InformationfortheJohnson,Browne,Keetna,andSnowsiteswasmainlyderivedfromsitereconnaissance(aircraftoverflights),reviewofexistinginformation,andpersonalcommunicationswithindividualsfamiliarwiththesites.Inadditiontotheabovesources,theinformationfortheChakachamnasitewassupplementedbyinformationcontainedinfef'lsibilitystudiesofthesitethatwerefundedbythePowerAuthority(Bechtel,1983).Therefore,theinformationbaseismuchmoreextensiveforthissitethantheotheralternativehydrosites.InformationontheProposedProjectwasderivedfromtheLicenseApplicationsubmissiontotheFERCandtheassociatedextensivestudies.453410/28408202-1 ]]:J'13.0PreviousStudiesNumerousstudiesofhydroelectricpotentialinAlaskahavepreviouslybeenundertaken(AlaskaPowerAuthority1983a;AlaskaPowerAdministration1980).Thesedateasfarbackas1947,andwereperformedbyvar,iousagenciesincludingtheFederalPowerCommission(1976),theu.s.ArmyCorpsof_Engineers(COE),theUnitedStatesBur,eauofReclamation(USBR),theUnitedStatesGeologicalSurvey(USGS1961),andtheStateofAlaska.TomeettheenergyneedsfortheRai1be1tRegion,technical,economlCandenvironmentalaspectsofhydroelectricpotentialinAlaskawereincludedinthePowerAuthority'sLicenseApplicationfortheProposedProject.Thescreeningofnon-SusitnahydroelectricalternativeswaspresentedinExhibitE,Chapter10oftheLicenseApplication.Theabovestudiesand,inparticular,theinventoriesofpotentialsitesbytheU.S.Arm)t(1981)andtheAlaskaPowerAdministration(1980)havebeenutilizedinpreparingthisAppendix.453410/38408203-1 14.0EvaluationMethodologyTheevaluationprocessforcomparingthealternativeswiththeSusitnaprojectinvolvedthefollowingsixbasicsteps:'1,jStep1:-Sitevisitbyfixedw~ngaircraft.-~eviewofavailabledata.-Determinationofkeyitemsforevaluation.'J]Step2 :-Developmentofpreliminarylayouts,basedonthesitevisit,availabledataanddesigncriteriaforthealternativedamtypesconsidered,includingallrelatedfacilitiesandstructures.-Developmentofplansforeachlayout.-Planimeteringofprojectfeaturesandtheimpoundmentzonestoobtainsurfaceareas.werenotused).(ValuespresentedlntheDEIS1J1JStep3:Step4:Step5:Step6:453410/4840820-DevelopmentofcostestimatesforeachlayoutbasedonthedrawingspreparedunderStep2.-Reviewofalllayoutsonthebasisoftechnicalfeasibility,cost,constructionmethodsandmaterials,uncertaintyof'basicdataandassumptions,safety,andenvironmentalimpacts.-Evaluationofeachalternativeproject.-ComparisonofthealternativeswiththeProposedProject.4-1 :11J:JThekeycriteriausedforevaluationofthealternativedamsiteswereasfollows:(a)Economic/EngineeringoConstructioncostestimate(basedonLicenseApplication)oAvailabilityofconstructionmaterials;oTechnicaladequacyoOperationandsafety.(b)EnvironmentalTothedegreepossible,environmentalcategoriesconsideredincompar1sonsofhydroelectricalternativeswerebasedontheFERCrequirementsforthepreparationoftheExhibitE"EnvironmentalReport"submittedaspartoftheLicenseApplicationfortheProposedProject.Thesecategoriesincludeprojectimpactsonthefollowing:oHumanResources:SocioeconomicsCulturalResourcesLandUseAestheticsInadditiontotheabovecriteriausedforcompar1ngalternatives,thecostsof~hefollowingitemswereconsidered,whereapplicable:].JJ1.Iooo453410/4840820RecreationVisualResourcesTerrestrialResourcesAquaticResourcesMeasurestominimizeorprecludethepossibilityofundesirableandirreversiblechangestothenaturalenvironment(e.g.fishpassagefacilities).4-2 -jj0J1J1J}'J'J]-,.1,_JJJ453410/4840820Measureswhichenhancethequalityaspectsofwaterandland.Carewastakenwhenincorporatingtheseaspectstoensureconsistencybetweenalternatives,i.e.thatallalternativesincorporatedthesamedegreeofmitigation.Forexample,thesemeasuresincludedreservoiroperationconstraintstominimizeenvironmentalimpactsandadoptionofaccessroadandtransmissionlinedesignstandardsandconstructiontechniqueswhichminimizeimpactonterrestrialandaquatichabitat.4-3 ]l1JlJ5.0DescriptionofProjects5.1GeneralThefollowingsections(5.2through5.6)outlinealternativehydroelectricprojectsconsideredforcomparisonwiththeDevilCanyonandWatanasites.Theextremelypreliminarylevelofstudywassufficienttoidentifythemajordesignfeaturesofeachalternative,commensuratewiththeavailabledata.Thedamlayoutsareconceptualratherthandefinitive,andare]intendedonly-togivearepresentativedesignforeachalternativethatprovidesanadequatebasisforcomparison.Majorfactorsconsideredincludetheassociateddiversionworks,spil1wa~s,andpowerfacilities;constructionmethodsandmaterials;capitalcostestimates;safetyofoperation;andimpactontheenvironment.Sensitivit.ytochangesintheavailabledataregardinggeology,topography,constructionmaterials,andthelevelofseismicactivityhavealsobeenconsidered.For'comparisonpurposes,projectdescriptionsarealsoincludedforDevilCanyon(Section5.7)andWatana(Section5.8).Itshouldbenotedthat1.JJprojectfeasibilityhasbeenestablishedfortheProposedProjectdamsthroughpreliminaryundergroundexplorations,investigations,anddesignstudies.5.2JohnsonDamandReservoirLocation.TheJohnsonsite~slocatedontheTananaRiver,120miles,}southeastofFairbanks.ThedamsiteisjustdownstreamfromtheconfluenceoftheJohnsonandTananariversatlatitude63°45'N,longitude144°38'W(Exhibits1and3).Climate.Theclimateoftheprojectareaisdescribedascontinental.Meanannualairtemperatureis23°F.Temperaturesrangefromameanminimumof-12°FinJanuarytoameanmaximumof68°FinJuly.Precipitationaverages453410/58408205-1 20inchesannually.drainagebasin.Permafrostconditionsexistatthedamsiteand1nthe1SeismicPotential.TheprojectislocatedinProbabilityZone2,accordingtoseismicriskmapsoftheUniformBuildingCode(ICBO1980).Thisisnotedasmoderatedamagecategory(correspondstointensityVIIontheModifiedMercalliIntensityScale).DrainageArea.Thedrainageareaabovethedamsite1S10,500squaremiles.Streamflow.TheTananaRiverstreamflowhasbeenrecordednearTanacross]](USGSGage.No.15476000)andatBigDelta.BigDeltarecordsareavailablefrom1948to1952andfrom1953to1957andhavesincebeendiscontinued.Tanacrossrecordsarecontinuousfrom1953to.thepresent.Since-therecordatTanacross1Slongerandcontinuous,theflowsatthedamsitewereestimatedfromTanacrossflowsbylinearproportiontothecatchmentarea.Theaverageannualstreamflowatthedamsiteisestimatedat9,800cubicfeetpersecond(cfs)orabout7,100,000acre-feetperyear.JohnsonReservoir-hasanestimated50-yearsedimentdepositionof400,000acre-feetintheactivestorageportionofthereservoir(U.S.BureauofReclamation1965).]Sediment.Basedonsedimentsamplestaken1ntheTananaRiverbasin,1..JProjectDescription.TheJohnsonReservoirwouldbeformedbytheconstructionofanearthdamacrosstheTananaRiver.Thedamwouldhaveamaximumheightof210feetfromthebaseatelevation1~280tothecrestatelevation1,490.Thecrestlengthwouldbeabout6,400feet.A2,000footlongsaddledamofundeterminedheight·wouldberequiredabout3.5milesnortheastofthemaindam.TheTananaRiverValley1Sknowntocontaindeep,permeableunconsolidatedsediments,andsuchdepositswouldmostlikelybepresentatthesite.Theunconsolidateddepositscouldcontainpermafrostexceptforashallow453410/58408205-2 'Jl'l~J1_Jsurfacezonethatthawsinsummer.Forseismicstabilityreasons,thesematerialswouldprobablyhavetobeexcavatedsothedamembankmentcouldrestonbedrock.Thepowerplantwouldhaveaninstalledcapacityof210megawatts(MW)witha50percentplantfactorifthepowerplant1.Snotlimitedbysystemenergyrequirements.ThegeneratorswouldbedrivenbyfourFrancisturbines.ReservoirCharacteristics.ThenormalmaX1.mumoperatinglevelofJohnsonReservoirwouldbeatelevation1,470feet.ThecorrespondingreserV01.rsurfaceareaandstoragevolumeare94,500acresand7,000,000acre-feetrespectively.Activestoragewouldbe5,300,000acre-feetafterthe50-yearsedimentallocationismade.Estimatedreservoirdrawdowncapabilitywouldbe80feet.Thisdrawdowncouldexposesome48,000acresofunsightlymudflatsand/orerodedslopesdevoidofanyvegetation.Themaximumdepthofthereservoirwouldbe190feetandretentiontimewouldbe11months.Reservoirlengthwouldbe36miles.ProjectOperation..Thedrawdownofthereservoirwouldstartwiththerecessionofflowinthefall.Thereservoirwouldbegraduallydrawndownthroughthewinter,reachingtheminimumreservoirlevelin._Mayofeachyear.AnnualfillingwouldcommenceinMayandcontinuefortheremainderofthesummer.Them1.n1.mumflowsfortheprojectarebasedonthosepresented1..0Table2-7oftheDEIS(seeSection9.0forafurtherdiscussionontheselectionoftheseminimumflows).Minimumflowswouldbe24,000cfsduringthemonthsofJune,JulyandAugustand3200cfsduringtheothermonths.TheJune,July,Augustflowof24,000cfsrepresentsthemaximumofthehistoricalQ90valueand1.Ssimilartotheaverageflowoccurring1..0thesummer.Consequently,duringdryhydrologicalyears,itmaynotbepossibletomaintainthisminimumflow.Maximumgrossheadwouldbe180feetandaveragegrossheadwouldbeapproximately149feet.Tailwaterelevationwouldbeatapproximatelyelevation1,290feet.Meanannualenergycould453410/58408205-3 ]]JJreachapproximately950Gigawatthours(GWh)ifenergyproductionisnotlimitedbythesystemrequirement.5.3BrowneDamandReservoirLocation.TheBrownesite1SlocatedontheNenanaRiver,approximately65airmilessouthwestofFairbanks(Exhibits1and4).SeeEBASCO1982.Climate.Theclimateoftheprojectarea1Sdescribedascontinental.Meanannuala1rtemperature1S23of.Temperaturesrangefromameanminimumof-12ofinJanuarytoameanmaX1mum0f69of1nJuly.Precipitationaverages20inchesannually.SeismicPotential.Theproject1Slocated.1nProbabilityZone3,perse1Sm1CriskmapsoftheUniformBuildingCode(leBO1980).Thisisnotedasmajordamagecategory(correspondstointensityVIIIandhigherontheModifiedMercalliIntensityScale).DrainageArea.Thedamsitehasatributarydrainageareaof2,450squaremiles.ThebasindrainsthefoothillsonthenorthsideoftheAlaskaRange•.Terrainthroughoutmuchofthebasinisrelativelyflat.]Streamflow.NenanaRiverstreamflowrecordsexistforthreelocations:JJJJNenanaRivernearWindy;NenanaRivernearHealy,andNenanaRivernearRex.TheNenanaRivernearWindy(USGSGageNo.15516000)hasadrainageareaof710squaremilesand22yearsofrecord(1951-1973).TheNenanaRivernearHealy(USGSGageNo.15518000)hasadrainageareaof1,910squaremilesand29yearsofrecord.TheNenanaRivernearRex(USGSGageNo.15518300)isneartheBrownedamsite.Thegagingstationhasadrainageareaof2,450squaremilesbutonly4yearsofflowdata.BasedontheNenanaRivernearHealyrecord,theaverageannualflowatthedamsiteisestimatedtobe4,500cfs(3,250,000acre-feet).Meanmonthlyflowsrangefromanaverageofabout500cfsinlatewinterto14,000cfsinJune..1453410/58408205-4 ]]J]'J1JSediment.TheBureauofReclamation(1965)estimatedthesedimentloadat1.2acre-feet/squaremile/yearor150,000acre-feetin50years.ProjectDescription.TheNenanaRiverflows~nagentlyslopingU-shapedvalley.Thesteepabutmentsexistingatthedamsiteindicatebedrockisnearlyexposedoneithersideofther~ver.Foundationconditionsarecommensur~tewithconstructionofanearthandrockfilldamatthissite.Thedamwouldbebuiltwiththecrestatelevation995+feetandthebaseatelevation730+feet.Thecrestlengthwouldbeabout6,300feet.Anogeetypegatedspillwaywouldbelocatedontherightabutment.Apowertunnelwouldbeconnectedthroughtheleftabutmenttoasurfacepowerhouse.FourFrancisturbines,eachratedat34,600horsepower(hp)atanetdesignheadof170feet,wouldbeinstalled.Thetotalcapacitywouldbe100MWataplantfactorof50percent.Constructionmaterialsmightbeobtainedfromtheadjacentrockoutcropsalongwithalluvialdepositsintherivervalley.ReservoirCharacteristics.TheBrowneReservoirwouldbeoperatedatanormalmaximumreservoirelevationof975feet.At'thiselevation,thereservoirwouldhaveasurfaceareaof12,500acresandatotalstorageof1,100,000acrefeet.Maximumdrawdowncapabilityofthereservoir~s85feet,correspondingtoaminimumreservoirelevationof890feet.Thisdrawdowncouldexpose7000+acresofunsightlymudflatsand/orerodedslopesdevoidofanyvegetation.Theactivereservoirstoragewouldbe.760,000acre-feet.Maximumdepthofthereservoirwouldbeabout205feet.Retentiontimewouldbe4months.Thereservoirlengthwouldbe11miles.ProjectOperation.thereservo~rwouldbegraduallyfilledeachyearduringthehighflowsummerperiodofMaythroughSeptember.Duringthewinterlowflowperiod,thereservoirwouldbegraduallydrawndown,reachingthem~n~mumreservo~relevationaboutMay.Minimumflowreleasesfromtheprojectwouldbe9,300cfsduringJune,JulyandAugustand1,400cfsduring453410/58408205-5 1'-11j'}]']jtheothermonths.ThesedischargesarebasedonreleasespresentedinTable2-7oftheDEIS.Withthemaximumreservoirelevationof975andatailwaterelevationof780feet,theresultingmaximumheadwouldbe195feet.Averagegrossheadwouldbeapproximately180feet.Meanannualenergyisapproximately440GWhifenergyproductionisnotlimitedbythesystemrequirement.5.4KeetnaDamandReservoirLocation.TheKeetnasite(Exhibits1and5)1SlocatedontheTalkeetnaRiver,approximately85milesnorthqfAnchorageand14milesnortheastofTalkeetna,approximately1.5milesdownstreamfromDisappointmentCreek.Climate.Theclimateoftheprojectarea1Sdescribedascontinental.Themeanannualairtemperatureis30°F.Temperaturesrangefromameanminimumof-2°FinJanuarytoameanmaximumof68°Fin'July.Precipitationaverages30inchesannually.Permafrostconditionsexistatthesiteandinthedrainagebasin.SeismicPotential.Theproject1Slocated1nProbabilityZone3,perse1sm1CriskmapsoftheUniformBuildingCode(ICBO1980).Thisisnotedasthemajordamagecategory(correspondstointensityVIIIandhigherontheModifiedMercalliIntensityScale).DrainageArea.Thedamsitehasatributarydrainageareaof1,260squaremiles.ThebasinlieseastoftheSusitnaRiveranddrainsthewesternslopesoftheTalkeetnaMountains.Thelowerelevationssupportgrowthoftimberandothervegetation,whiletheupperelevationshavelittleornovegetalcover.Streamflow.StreamflowrecordsoftheTalkeetnaRiverareavailablefromJune1964tothepresenttimeforagage5-milesupstreamfromtherivermouth(USGSGageNo.15292700).Fortheenergysimulationstudiesconducted453410/58408205-6 ):]]]\JforthisAppendix,14yearsofstreamflowdatawereused(1964-1978).MeanannualdischargeattheKeetnadamsiteforthisperiodwasestimatedtobe2,500cfs(1,800,000acre-feet)basedonaproportioningofflowbydrainagearea.Sediment.ApproximatelyS1.Xpercentofthedrainagearea1.Sglaciated.USGSsedimentdischargemeasurementsfrom1981through1983attheTalkeetnaRivergagingstationindicatethatthesedimentloadisapproximatelyhalfofthesedimentloadoftheSusitnaRiverabovetheChulitnaRiver.BasedonaproportioningofthesedimentloadbydrainageareaandtrapefficiencesadaptedfromBrune(USBR1977),itwasdeterminedthat65,000acre-feetofsedimentwouldaccumulateinthereserV01.r1.na50yearperiod.ProjectDescription.Attheprojectsite,theTalkeetnaRiverflows1.nasteep-walled,U-shapedvalley.Thenearverticalabutmentsindicatebedrock1.Snearlyexposedoneithersideoftheriver.Inspfarascouldbedeterminedfromtheaerialreconnaissance,foundationconditionswouldallowconstructionofeitheranearthandrockfilldamoraconcretearchdamatthissite.Thedamwouldbebuiltwiththecrestatapproximatelyelevation965andthebaseatelevation550+feet.Thecrestlengthwouldbeabout1,200feet.Thediversionandpowertunnelswouldbelocatedontheleftabutmentalongwithanogeetypegatedspillway.ThesurfacepowerhousewouldbeconnectedtothereserV01.rbya1,300!feetlongtunnel.Thepowerplantwouldhaveaninstalledcapacityof100MWandaplantfactorof49percent.Twenty-fivemilesofa"ccessroadwouldberequiredfromTalkeetnatotheproject.Constructionofthisaccessroadwouldinvolveapproximately300acresofright-of-way._1453410/58408205-7 'J:1°1.J1JJConstructionmaterialsmightbeobtainedfromtheadjacentrockoutcropsandthealluvialdepositsintherivervalley.ReservoirCharacteristics.TheKeetnaReservoirwouldhaveanormalmaX1mumwatersurfaceatelevation945feet.Atthiselevation,thereservoirareawouldbe5,500acres.Totalreservoircapacitywouldbe850,000acre-feet,including350,000acre-feetofdeadstorageand500,000acre-feetoflive,istorage.Drawdowncapabilitywouldbe125feet.Thisdrawdowncouldexposeabout2000+acresofunsightlymudflatsand/orerodedslopesdevoid0+anyvegetation.Maximumreservoirdepthwouldbeabout240feet.Retentiontimewouldbe5.5months.Thereservoirlengthwouldbe10miles.ProjectOperation.TheKeetnaReservoirwouldbedrawndowntoitsminimumlevelinMayofeachyear.Duringthehighflowsummerperiod(MaythroughSeptember)thereservoirwouldbegraduallyfilled.Duringthefallandwinter,thestoredwaterwouldbegraduallyreleaseduntilthem1n1mum·reservoirelevationisreachedinMay.Minimumflowwouldbe5,000cfsduringthesummermonthsofJune,JulyandAugustand720cfsduringthewintermonths.TheseflowsarebasedonthosepresentedintheDEIS(seeTable2-7).Maximumgrossheadwouldbe330feetiandtheaveragenetoperatingheadabout286feet.Tailwatere1ev~tionwouldbeatapproximatelyelevation615feet.Meanannualenergy1Sapproximately430GWhifenergyproductionisnotlimitedbythesystemrequirement.5.5SnowDamandReservoirLocation.Thedamsite1SontheSnowRiverintheKenaiPeninsulaatr1vermile8.(latitude60°l8'N,longitude149°l6'W)(Exhibits1and6).Climate.Theclimateoftheprojectarea1Sdescribedascontinental.Themeanannualairtemperatureisabout36°Fwithtemperaturesra~g1ngfromaJ453410/58408205-8 l]]]]JJ]]1"j]meanJanuarym~n~mumof12°FtoameanJulymax~mumof63°F.Precipitationaveragesapproximately100inchesannually.SeismicPotential.TheprojectislocatedinProbabilityZone4,accordingtoseismicriskmapsoftheUniformBuildingCode(lCBO1980).Thisisnotedasthehighestriskcategory.DrainageArea.Thedamsitehasatributarydrainageareaof105squaremiles.Themountainousbasinliesapproximately12milesnorthofSewardintheKenaiMountains.Thelowerelevationssupportthegrowthoftimberandothervegetationwhiletheupperelevationscontainnumerousglacierswithlittleornovegetalcover.Streamflow.SnowRiverstreamflowhas.beenmeasuredatapointapproxiately1.5milesupstreamfromtheproposeddamsite.Therecordsfromthisgage("SnowRivernearDivide")areavailablefromDecember1960toJuly1965.Theserecordswereextendedbycorrelatingwiththerecordsfromthe"TrailRiver"gagenearLawingwhichareavailablefromMay1947.However,thefloodscausedbyglacialoutbursts,astheywereconsideredintheflowdata~ntheresponsestoExhibitsBandDoftheLicenseApplicationsubmittedtoFERConAugust18,1983,werenotconsidered~nthisstreamflowanalysisorthepowerandenergystudy~nSection9.Basedonthiscorrelation,theaverageannualstreamflowatthedamsite~sestimatedat660cfs(478,000acre-feet).Mean~onthlyflowsvaryfromaslittleas10cfs~nMarchto,approximately2,000cfsintheJulythroughSeptemberperiod.FloodPotentialFromGlacierDammedLake.Releaseofwaterfroman~cedammedlakehighabovetheSnowRiverValleyhasproducedfloodflowsofaboutthesamemagnitudeasstorms(PostandMayo1971).The'outburstfloodof1967wasestimatedat20,000cfs.Historicalrecordsindicatethattheglacialoutburstfloods~ntheSnowRiverValleyfromtheglacier-filledlakehaveoccurredevery2to3years.Should"outburst"flowsoccur453410/58408205-9 'Jsimultaneouslywithanon-outburst£lo'd,thecombinedflowcouldexceed40,000cfs.ProjectDescription.Atthedamsite(Exhibit6),theSnowRiverflowsinadeep,narrowgorgeincisedinbedrockonthefloorofasteep-walled,U-shaped,glacialvalley.Bedrock1.Swellexposed1.nthenear-verticalabutmentsalthoughthinoverburdenmantlesportionsoftheupperleftabutment.Thebedsstrikenearlyduenorth,normaltothecanyon,anddipsteeplyupstream.Insofarascouldbedeterminedfromaerial]J]reconnaissance,geologicconditionsarefavorablefqrconstructionofeitherarockfilloraconcretearchdamatthissite.Apowertunnelalongtherightvalleywallwouldpenetraterocksimilartothatexposedatthedamsite.Constructionmaterialsmightbeobtainedfromtheadjacentrockoutcropsalongwithalluvialandglacialdepositsfromthelowerreachesofther1.vernearitsconfluencewiththeSouthForkSnowRiver,approximately4milesdownstreamfromthesite.Forestimatingpurposes,it1.Sassumedthat·adamwouldbebuiltwiththecrestatapproximatelyelevation1,210feetandthebaseatelevation900feetforamaX1.mumstructuralheightof310+feet.Thecrestlengthwouldbeabout820feet.Thediversionandpowertunnelswouldbelocatedontherightabutmentandaspillwaywouldbeconstructedatthesouthernendofthereservoir,approximately1milefromthedam.Thepowerplantwouldbeconnectedtothereservoirby10,000feetof+ll-foot-diametertunneland2,000feetof+8-foot-diametersurfacepenstock.Thepowerplantwouldhaveaninstalledcapacityof63MWwitha50percentplantfactor.453410/58408205-10 ReservoirCharacteristics.TheSnowReservoirwouldhaveanormalmaximum]']]Joperatinglevelof1,200feetabovesealevel.Atthiselevation,thereservoirsurfaceareawouldbe3,200acresandthetotalstoragewouldbe179,000acre-feet.Withatotaldrawdowncapabilityof150feet,theactivereservoirstoragewouldbe173,000acre-feet.Thisdrawdowncouldexpose2200+acresofunsightlymudflatsand/orerodedslopesdevoidofvegetation.Maximumdepthofthereservoirwouldbeabout300feet.Retentiontimewouldbe4months.Reservoirlengthwouldbe7miles.LowerParadiseLakewouldbeinundatedatfullpoolelevation.ProjectOperation.DuringthehighrunoffperiodofJune,July,AugustandSeptemberthereservoirwouldbegraduallyfilledfromitsminimumelevationof1,050feet.DuringtheperiodOctoberthroughMay,thereservoirwouldbedrawndowntoitsminimumlevel.Minimum.flowfortheprojectwouldbe740cfsduringJune,JulyandAugustand210cfsatothertimes.TheseflowsarebasedonthosedescribedinTable2-7oftheDEIS.Tailwater.levelwouldbe500feet,resulting~namax~mumgrossheadof700feetatfullpoolelevation.Theaverageheadwouldbe620feet,allowingfor30feetofheadlossinthepenstock.Theenergyoutputcapabilitie~oftheSnowProjectwerereevaluatedusingrevisedstreamflowdata.The100MWinstalledcapacity,presentedinboththeLicenseApplicationandfheDEIS,waspreviouslybasedoncombinednormalstreamflowandflowresultingfromglacialoutburstflooding.ThishighflowgavethefalseimpressionthattheSnowRivercouldproducemorecontinuousenergythanitrealisticallycould.Hence,a100MWpowerplantisnotappropriateforthisproject.Subsequent'studyconsideringonlyactualstreamflowdata(excludingflowfromglacieroutbursts)indicatesthata63MWpowerplantismorerealistic,basedonaplantfactorofabout50percent.Thisreducedcapacityisusedinthisanalysisaspartofamorerealisticpreliminarydesign.Meanannualenergy~sapproximately270GWhiftheenergyproductionisnotlimitedbythesystemenergydemand.453410/58408205-11 .J]5.6ChakachamnaDamandReservoirLocation.TheChakachamnasitewouldbelocatedontheChakachatnaRiver,approximately80mileswestofAnchorage(Exhibits1and7).Climate.Theclimateoftheprojectarea~sdescribedastransitional.Meanannualairtemperatureis28°F.Temperaturesrangefromameanminimumof8°FinJanuarytoameanmaximumof69°FinJuly.Precipitationaverages80inchesperyear•SeismicPotential.Theprojectwouldbelocated1nProbabilityZone3,accordingtoseismicriskmapsoftheUniformBuildingCode(ICBO'1980).ProximitytoavolcanoplustheseismicpotentialputChakachamna~nthemajordamagecategory(correspondstointensityVIIIandhigherontheModifiedMercalliIntensityScale).DrainageArea.miles.Thedamsitehasatribut~rydrainageareaof1,120squareI.JStreamflow.ContinuousstreamflowrecordsfortheChakachatnaRivernearTyonek(USGSGageNo.15294500)areavailablefortheperiodJune1959toAugust1971.ThisstationislocatedattheoutlettoChakachamnaLake.Meanannualflowis3,750cfs(2.7millionacre-feet).ProjectDescription.Theproject(Exhibit7)~stheBechtelrecommendedalternative(AlternativeE,Bechtel1983).ItwouldconsistofarockfilldikeconstructedattheoutletofLakeChakachamna.Thedikewouldhaveacrestlengthof600feetandacrestelevationof1,177feet.WaterwouldbedivertedtoapowerhouselocatedneartheMcArthurRiverv~aatunnel10mileslong.Thediameterofthispowertunnelwouldbe24feet.FourverticalFrancisturbineswouldbeinstalledwithatotalinstalledcapacityof330MW.Theplantfactorwouldbe45percent.Fishpassagefacilitieswouldbeincorporatedinthedesign.453410/58408205-12 ClJ..•~]JJReservoirCharacteristics.ChakachamnaLakewouldhaveanormalmaximumwaterlevelof1,155feet.Reservoirareaatthise1evation.wou1dbe17,500acreswhilethetotalvolumewouldbe4,483,000acre-feet.Activestoragewouldbe1,105,000acre~feet,correspondingtoadrawdowncapabilityof72feet.Thisdrawdowncouldexpose2200~acresofunsightlymudflatsand/orerodedslopesdevoidofvegetation.Retentiontimewouldbe1.65years•ProjectOperation.Theprojectwouldbeoperatedtoprovideforfisheryreleases.FromMaythroughSeptembertheinstreamflowreleasewouldbe1,094cfs.Duringtheremainderoftheyeartheinstreamflowreleasewouldbeabout365cfs.(ThesearetheflowsrecommendedinAlternativeE,Bechtel1983).TheminimumflowsrecommendedinTable2-7oftheDEIScouldnotbesatisfiedforChakachamnaAlternativeE.SincetherequirementscouldbesatisfiedforAlternativeD,thisAlternativewasusedinthepowerandenergyanalysispresentedinSection9.Maximumgrossheadwouldbe945···feetandtheaveragenetoperatingheadabout905feet.Tailwaterelevationwouldbeat210feet.Meanannualenergyproductionisestimatedtobe1,301GWh.5.7WatanaDamandReservoirLocation.ThepotentialdamsiteislocatedintheupperSusitnaRiverBasinofSouthcentra1Alaska,atapproximatelyRiverMile184.TheWatanadamsite1Sapproximately140milesnorth-northeastofAnchorage.Climate.Theclimateoftheprojectarea1Sdescribed'ascontinental.Meanannualairtemperatureis28°F.Theaveragetemperaturerangeisfrom-3ofto64of.Precipitationaverages24inchesperyear.Averageannualsnowfallisapproximately100inches.SeismicPotential.Therearenoactivefaultscrossingthesite.ThemajorsourceofearthquakeshakingatthesitemaybeattributedtotheBenioffZone(aninterp1ateboundary)underlyingthesiteatdepth,theDenalifault(atadistanceofapproximately43miles),theCastleMountainfault453410/58408205-13 ]JJI_)1_..J(atadistanceofapproximately65miles),andsmallerlocalearthquakesoccurr~ngwithnoapparentsurfaceexpression~nthecrustoftheTalkeetnaterrain.Themaximumlocalearthquakewhichneedstobeconsideredwouldhaveamagnitudeof6(Richterscale)andcouldpossiblyoccurveryclosetothedamsite(Woodward-Clyde1983).DrainageArea.Thedamsitehasatributarydrainageareaof5,180squaremiles.ThedrainagebasinisboundedbytheAlaskaRangetothenorthandwest,andtheChugachMountainsandtheGulfofAlaska.tothesouth.Topographyisvariedandincludesrugged,mountainousterrain,plateaus,anderoadrivervalleys.Streamflow.SusitnaRiverstreamflowhasbeenestimatedusingalineardrainagearea-flowrelationshipbetweenthe.GoldCreekandCantwell(VeeCanyon)gagesites.TheaveragestreamflowattheWatanadamsite~sestimatedtobeintherangeof7,990cfs(5,788,500acre-ft/yr.).Sediment.Reservoirsedimentation~sestimatedtobeabout210,000acre-feetinWatanareservoirovera50yearperiod,basedonatrapefficiencyof100percent.Thiswouldresult~nalossofdeadstorageofabout3.7percent.ProjectDescription.TheSusitnaRiverflows~naU-shapedvalley.Thesteepabutmentsexistingatthedamsitereflectthebedrockwhichisexposedoneithersideofther~ver.Basedonfeasibilitylevelundergroundexplorations,theWatanafoundationconditionsarecommensuratewithconstructionofasatisfactoryearthandrockfilldamatthissite.Thedamwouldbebuiltwiththecrestatelevation2,210andthebaseatelevation1,375.Thecrestlengthwouldbeabout4,100feet.Anogeetypegatedspillwaywouldbelocatedontherightabutment.Apowertunnelwouldbeconnectedthroughtherightabutmenttoanundergroundpowerhouse.sixgeneratorswouldbeinstalledforatotalcapacityof1,020MW.TheJ453410/58408205-14 ,1I])jI\~_._J1,JturbineswouldbeoftheFrancistype,andhaveatotalratedoutputof250,000hpataratedheadof680feet.Constructionmaterialscouldbeobtainedfromtheadjacentrockoutcropsalongwithalluvialdepo~itsintherivervalley.ReservoirCharacteristics.TheWatanaReservoirwillbeoperatedatanormalmaximumoperatinglevelofE12185ftabovemeansealevel.AverageannualdrawdownwillbetoE12093ftwithWatanaoperatingalong.ThemaximumdrawdownwillbetoE12065ft.AtE12185ft,thereservoirwillhaveasurfaceareaof38,000acresandatotalvolumeof9.47millionacre-feet.Livestoragewillbe3.74millionacre-feet.Maximumdepthwillbe735feetapdthemeandepthwillbe250feet.Thereservoirwillhavearetentiontimeof1.65years.ProjectOperation.AswithmanyAlaskanhydroprojects,Watanawillbeoperatedsothatsummerflowswillbestoredforrelease1nwinter.Generally,theWatanareserV01rwillbeatornearitsnormalma'X1mumoperatinglevelof2185feeteachyearattheendofSeptember.Gradually,thereservoirwillbedrawndowntomeetwinterenergydemand.Theflowduringthisperiodwillbegovernedbythewinterenergydemand,thewaterlevelinthereservoir,andthepowerhousecharacteristics.InearlyMay,thereserV01rwillreachitsm1n1mumannuallevelofapproximatelyE12093ftandthenbegintorefillwiththespringrunoff.Flowinexcessofboththedownstreamflowrequirementsandpowerneedswillbestoredduringthesummeruntilthereservoirreachesthenormalmaximumoperatinglevelof2185ft.Theproposedminimumflowsfortheprojectare5000cfsfromOctoberthroughApril,6000cfsinMay,JuneandJuly,12,000cfsinAugustandthefirsthalfofSeptemberand6000cfsinthelatterhalfofSeptember.Tai1waterlevelwouldbe1455feet,resulting1namaximumgrossheadof730.Meanannualenergygenerationisestimatedtobe3500GWh.453410/58408205-15 J1)Furtherinformationonprojectoperationcanbefound~nExhibitBChapter3oftheLicenseApplication.5.8DevilCanyonDamandReservoirLocation.Thepotentialdamsite(Exhibits1and8)islocatedintheupperSusitnaRiverBasinofSouthcentralAlaska,approximatelymidwaybetween.AnchorageandFairbanks.Climate.Theclimateoftheprojectareacomprisescold,drywintersandwarm,moderatelymoistsummers.Theaveragetemperaturerangeisfrom-3°Fto64°F.Precipitationaverages24inchesperyear.Averageannualsnowfallisapproximately100inches.SeismicPotential.Therearenoactivefaultscrossingthesite.Themajorsourceofe'arthquakeshakingatthesitemaybeattributedtothe'Benioffzone(aninterplateboundary)underlyingthesiteatdepth,theDenali"fault(atadistanceofapproximately40miles),theCastleMountainfault(atadis,tanceofapproximately70miles);andsmallerlocalearthquakesoccurr~ngwithnoapparentsurfaceexpression~nthecrustoftheTalkeetnaterrain.Themaximumlocalearthquakewhichneedstobeconsideredwouldhaveamagnitudeof6andcouldpossiblyoccurclosetothedamsite(Woodward-Clyde1983).DrainageArea.Thedamsitehasatributarydrainageareaof5,810squaremiles.ThedrainagebasinisboundedbytheAlaskaRangetothenorthandwestandtheChugachMountainsandGulfofAlaskatothesouth.Topographyisvariedandincludesrugged,mountainousterrain;plateaus;andbroadrivervalleys.Streamflow.Riverflowhasbeenestimatedusinglineardrainagearea-flowrelationshipsbetweentheUSGSGoldCreekandCantwell(VeeCanyon)gagingstations.Theaverageannualstreamflowatthedamsiteisestimatedtobe9,080cfs(6,578,000acre-ft/yr.).1)453410/58408205-16 I1'J]Sediment.WithWatanainoperation,about16,100acre-feetofsedimentwouldaccumulate~nDevilCanyonreservoirina50yearperiod.Thisis2.2percentofthedeadstorageinthereservoir.ProjectDescription.TheSusitnaRiverflows10aU-shapedvalley.Thesteepabutmentsexistingatthedamsitereflectthebedrockwhichisexposedoneithersideoftheriver.Basedonfeasibilitylevelundergroundexplorations,theDevilCanyonfoundationconditionsarecommensuratewithconstructionofasatisfactoryconcretearchdamatthissite.Thedamwouldbebuiltwiththecrestatelevation1,463feetandthebaseatelevation820+.Thecrestlength,includingthrustblocks,wouldbeabout1,650feet.Anogeetypegatedspillwaywouldbelocatedontherightabutment.Apowertunnelwouldbeconnected,throughtherightabutmenttoanundergroundpowerhouse.Fourgeneratorswouldbeinstalledforatotalcapacityof600MW.TheturbineswouldbeoftheFrancistype,operatingataratedfullgateoutputof205,000hpataratedheadof590feet.Averagetailwaterwouldbeataboutelevation850feet.Constructionmaterialswillbeobtainedfromtheadjacenthighterracesalongwithalluvialdepositsintherivervalley.ReservoirCharacteristics.DevilCanyonreservo~rwillbeoperatedatanormal-maximumoperatinglevelofEl1455ftabovemeansealevel.Averageannualdrawdownwillbe28feetwiththemaximumdrawdownequalling50feet.AtEl1455ftthereservoirwillhaveasurfaceareaof7800acres(3120ha)andavolumeof1.09millionacre-feet.Activestoragewillbe350,000acre-feet.Themaximumdepthwillbe565feetandthemeandepthwillbe140feet.Thereservoirwillhavearetentiontimeof2months.ProjectOperation.".AfterDevilCanyonoperatedasapeakingplantandDevilbaseloadedplant•comesonline,CanyonwillbeWatanawillbeoperatedasa. J453410/58408205-17 1JJEachSeptember,theWatanareservoirwillbefilleduptoitsmaXl.mumwaterlevel.FromOctobertoMaythereservoirwillnormallybedrawndowntoapproximatelyEl2080ft,althoughduringdryyearsthereservol.rwillbedrawndowntoaml.nl.mumreserVOl.rlevelof2065ft.InMay,thespringrunoffwillbegintofillthereservoir.However,thereservoirwillnotbeallowedtofillaboveEl2185ft.FromNovemberthroughtheendofJuly,DevilCanyonwillbeoperatedatthenormalmaximumheadpondelevationof1455fttooptimizepowerproduction.DuringAugustandearlySeptember,theDevilCanyonreservoirlevelwillbedrawndowntoaml.nl.mumlevelof1405ft.Whenthedownstreamflowrequirementsdecreaseinmid-September,theDevilCanyonreservoirwillbefilledtoEl1455ft.TheproposedminimumflowrequirementswillbeunchangedwhenDevilCanyoncomesonline.AtDevilCanyon,tailwaterlevelwouldbe850feet,resultingl.namaXl.mumgrossheadof605feet.MeanannualenergygenerationforbothWatanaandDevilCanyoncombinedwillbe6900GWh.FurtherinformationonprojectoperationcanbefoundinExhibitBChapter3oftheLicenseApplication(AlaskaPowerAuthority1983a).453410/~8408205-18 ]IJ6.0Engineering-AssessmentofAlternativeProjects6.1SiteAssessment6.1.1JohnsonDamandReservoir6.1.1.1General.TheJohnsonprojectlocationandlayoutarepresentedonExhibits1and3.Access.Nospecialornewaccesswouldberequired.AccesstothesitewouldbeprovidedbytheexistingAlaskaHighway.Approximately4,500feetofabandonedAlaskaHighwaywouldprovideon-siteaccesstothedamsite.ItmaybenecessarytoupgradeportionsoftheAlaskaHighwayandhighwaybridgestoallowfortheheavierconstructiontraffic.RiverDiversion.Basedontheassumptionthatrockconditionsareadequatefortunnelling,adiversiontunnel(~2,500feetlong)wouldbeprovidedthroughtherightabutment.Anominallengthofdiversiontailracechannel(100to200feet)wouldalsoberequired.Upstreamanddownstreamdiversioncofferdamshavingacombinedlengthof"approximately3,500feetwouldberequired.Camp.Theconstructioncampwouldbelocated1naflatareaapproximately4.5milesdownstreamoftheimmediateprojectworkarea.Itwouldcoveratotalofabout100acresofland.OnsiteRoads.Onsiteroadswouldconnecttheconstructionareas,borrowareasandquarry,camp,etc.totheAlaskaHighwayasthemainaccess.Minimalfoundationexcavationorstabilizationmayberequired.Theroadswouldhaveaminimumwidthof20to30feet.ImperviousBorrow.Animperviousborrowofapproximately11.8x106cubicyardsmaybeprovidedfromanarealocatedinalow,flatfloodplainbetween453410/68408206-1 111JJjIJLakeGeorgeandtheTananaRiver,andbetweenthecampanddamaxis.However,thefloodplainalongtherivermayprovetocontaininsufficientimperviousborrow,inwhichcaseitmaybenecessarytoobtainnecessaryborrowathigherelevations.Thiswouldinvolvetheconstructionofon-siteroadsalongsteepslopes,withlargeexcavations,creatingpossiblestabilityproblems.PerviousBorrow.Theentireperv10!-1sborrowcapacityof0.6x106cubicyardsmaybeobtainedfromexistingupstreamgravelpits,theriverchannelwithinthereservoirarea,orboth.ThestretchofAlaskaHighwaypass1ngthroughthereservoirareamaybeusedforhaulingperviousmaterials.Asufficientquantityofperviousmaterialappearstobeavailableon-site.RockBorrow.Approximately45,000cubicyardsofquarryrockareneededtosatisfyprojectneeds,notconsideringconcreteaggregate.Aminimalquarrywouldprovideforallrockneeds.Relocations.TheJohnsonprojectwouldrequ1reextensiveandexpensiverelocations.About23milesofexistinghighwaywouldhavetoberelocatedtothesouthofthereserV01r,requ1r1nga200-footwide,clearedright-of-way(560~acres)atacostinexcessof23milliondollars.Therelocatedrbadwouldbebenchedintosteeperslopesandrequirelargerexcavationsthanatthepresentlocation,resultinginmanyhigh,exposedexcavationslopeswhichdonotpresentlyexist.Aswiththehighway,approximately23milesofabove-groundpipeline!/wouldhavetoberelocated.Ifthepipelinerelocationdoesnotcoincidewiththehighwayrelocation,accessforthepipelineconstructionwouldalsohavetobeprovided.1/Thestatusofthepip.eline1Scurrentlyundeterminedbut,usingaworst-caseassumption,istreatedhereinasanactivepipeline.IJ453410/68408206-2 :J~l]]]1J1_JJAnewhighwaymaintenancestationwouldbeprovidedadjacenttotherelocatedhighway,completewithaccessfromthehighway.Itwouldencompassanareaofabout8acres.Also,thecommunityofDotLakeandtheDotLakelandingstripwouldberelocatedtothesouthrimofthereservoir.ThecommunityknownastheLivingWordwouldalsoneedtoberelocatedtoanareaoutsidetheprojectlimits.Exi:stinggravelpits,whichwillbeinundateduponreservoirfilling,mayhavetobereplacedwithnewsitesoutsidethereservoirareaJTransmission.TransmissionlineswouldextendfromtheJohnsonpowerhousesubstationalongtheAlaskaand_RichardsonhighwaystoFairbanks,whereitmayormaynotbejoinedwiththeAnchorage-FairbanksIntertie(Exhibit2).Thelengthofthelinewouldbeabout135miles,andwouldrequirea100-footwideright-of-way(1640~acres).6.1.1.2DamEmbankment.NospecialproblemsconcerningdamdesignandconstructioRareapparentatthistime.Theembankmentwouldbeazonedsectionwithfinergrained,moreimperviousmaterialsplacedupstreamofthedamaxis,andthemo~eperviousmaterialsplaceddownstreamoftheaxis.Aninclinedchimneydrain,convertedtoadownstreamblanketdrain,wouldseparatethetwozones.Thedamwouldhavea30-footwidecrest,acrestlengthof6,400feet,amaximumheightof210feet,andabasewidthofabout1,200feetatitsmaximumsection.A2,OOO-footlongsaddledamofundeterminedheigh~andzon1ngwouldberequiredapproximately3.5milesnortheastofthemaindam.FoundationTheTananaRiverValleycontainsdeep,permeable,unconsolidatedsediments,whicharereportedtobepermanentlyfrozenexceptfornearsurfacedepositswhicharesubjecttosummerthaw.Itismostlikelythatthesedeposits453410/68408206-3 ]"]]]J]J]1J(whichcouldextendfrom100to200feetindepth)wouldhavetobecompletelyremovedfrombeneaththedam,andthedamfoundedonthebedrocksurface.Disposal.Wastedispbsalwouldbeupstreamofthedamwithinthereservoirareaandbelowtheminimumnormalreservoirlevel.Powerhouse.The210MWsurfacepowerhousewouldbesituatedinoradjacenttotheTananaRiverchannel.Minimalapproachandtailracechannelexcavationwouldberequired.Spillway.Thespillwaywouldbeconstructed~ntheTananaRiverchanneladjacenttothepowerhouse.Theembankmentwouldflankthepowerhouseandspillwaystructures.Minimalapproachandtailracechannelexcavationmayberequired.Reservoir.Thereservoirsurfaceareawouldbe94,500acres.Beingsoclosetopublictransportationfacilities,thereservoirwoulddisrupttransportationfacilities,andwoulddisplacecommunities.BasedonsedimentsamplestakenintheTananaRiverbasin,theactivestorageportionofthereservoirhasaSO-yearsedimentdepositionof400,000acre-feet,whichwouldresult~nmudflatgenerationattheupstreamendofthereservoir.ExistingandfuturetransportationontheTananaRiverwouldbedisruptedbytheproject.Lftheriveristobekeptnavigable,lockswouldhavetobeincludedinthedesignandthiswouldhaveasubstantialimpactonthecostoftheproject.6.1.2BrowneDamandReservoir6.1.2.1General.ThelocationandlayoutoftheBrowneprojectarepresentedonExhibits1and4.453410/68408206-4 :1]]]]]"Access.Nospecialornewaccesstothesitewouldberequired.AccesswouldbeprovidedbytheGeorgeParksHighwayandaccesstoapoint3milesdownstreamofthedamsitewouldbeprovidedbytheAlaskaRailroad.ItmaybenecessarytoimproveportionsoftheGeorgeParksHighwayandbridges,andtherai1bedtoprovidefortheheavierconstructiontraffic.RiverDiversion.Aconventionaltunneldiversionwouldbeutilized,ifrockconditionsallow.Adiversiontunnel2,000feetlongwouldbeprovidedthroughtherightabutment.Adiversiontailracechannel(1,000to1,500feetinlength)wouldprobablyalsoberequired.Upstreamanddownstreamdiversioncofferdamshavingatotallengthofapproximately3,500feetwouldberequired.Camp.Camp(s)wouldbelocatedl.nrelativelyflatareasoutsideoftheimmediateprojectworkareaandreserVOl.r,coveringatotalofabout100acresofland.OnsiteRoads.Onsiteroadswouldconnecttheconstructionareas,borrowareasandquarry,camp,etc.withthemainaccess.Foundationexcavationorstabilizationmayberequired.Theroadswouldhaveaminimumwidthof20to30feet.]ImperviousBorrow.requiredexcavation.AllnecessaryimperviousborrowmaybeobtainablefromAminimumborrowareawouldbeprovided.JPerviousBorrow.Approximately22.3x106cubicyardsofpervl.ousborrowmaterialwouldberequired.Allperviousborrowwouldbetakenfromtheriverandriverbanks.RockBorrow.Allrockneedscouldlikelybesatisfiedthroughrequiredexcavations.However,aminimumquarrywouldbeprovidedtosatisryfilterandconcreteaggregateneeds.453410/68408206-5 1J1]JJRelocations.BrownerequiresextensiveandexpenS1.verelocations.Approximately16milesofrailroadwouldberoutedaroundthereservoirtotheeastatacostestimatedtobeinexcessof15milliondollars.Becauseofthemoreruggedterrainandsteeperslopes'thatexistalongthepresentalignment,largelocalizedexcavationswouldberequired.Aright-of-way50feettoeachsideofthealignmentwouldbeprovidedandclearedforconstruction.Approximately8.5milesofhighwaywouldberelocatedwestofthereservo1.r,anda200footwide,clearedright-of-waywouldberequired(200~acres).Therelocatedroadwouldbebenchedintosteeperslopesthanatitspresentlocation,resulting1.nhigherexposedexcavationslopesthanpres~ntlyexist.ExistingGoldenValleyElectricAssociationtransmissionfacilitieswouldhavetoberelocatedeitheralongtherelocatedhighwayalignment,therelocatedrailroadalignment,orcombinedwiththetransmissionconnectiontoFairbanksaspresentedinthe'LicenseApplication.TherouteofthistransmissionlineconnectiontoFairbankswouldhavetobemodifiedfromtherouteshownintheSusitnaProjectLicenseApplication,toanalignmentjusteastofthereserV01.r.Transmission.TransmissionlineswouldextendfromtheBrownepowerhousesubstation,acrosstheNenanaRiver,andjointheproposedHealytoFairbankstransmissionconnection,whichwouldbeconstructedaspartoftheproject,atapointabout2mileseastofthedamrightabutment.Thelinewouldbeapproximately4.5milesinlength,andwouldreqU1.rea100-footwideright-of-way(60+acres).ProposedtransmissionalignmentsareshownonExhibit2•.6•1.2.2DamEmbankment.Theembankmentwouldbeazonedrolledfillconsistingofacentral,imperviouscore,andpervious/rockfillshells.Itwouldhavea30-J453410/68408206-6 ~lJ]]']]]]]footwidecrest,acrestlengthof6,300feet,amax~mumheightof265feet,andabasewidthofabout1,500feetatitsmaximumsection.Foundation.Amoderatelydeepexcavationwouldberequired.Approximately50feetofmaterialwouldhavetobeexcavatedthroughoutthevalleyfloodplain(4,000to4,800feetinlength)beneaththecoreandshellsofthedam.Near-surfacerockexistsatbothabutments.Disposal.Wastedisposalwouldbeupstreamofthedamwithinthereservoirarea.Itwouldbetoanelevationbelbwtheminimumnormalreservo~rlevel.Powerhouse.Typicalpowerhousedesignan~constructionwouldbe'applicabletotheBrownepowerhouse.Reservoirwaterwouldbetransportedtothe100MWsurfacepowerhousebyapowertunnelthroughtheleftabutment.A1,500footlongdischargechannelwouldtransportdownstreamdischargestotheriver.Spillway.Thespillwaywouldbeconstructedinanexcavationthroughthesteep,rightabutmentrock.Nominalapproachandtailracechannelexcavationmayberequired.Reservoir.Thereservoirsurfaceareawouldbe12,500acres.Becauseofproximitytopublictransportationfacilities,itcoulddisrupttransportation,anddisplacecommunites.Schedule.RelocationswouldhavetobeexecutedpriortoprojectconstructiontominimizetheimpactoftheBrowneprojectconstructionontheenvironment.6.1.3KeetnaDamandReservoir6.1.3.1General.ThelocationandproposedlayoutoftheKeetnaprojectarepresentedinExhibits1and5.453410/68408206-7 1]J]]JAccess.Approximately25milesofaccessroadwouldberequiredfromTalkeetnaeastalongthesouthbankoftheTalkeetnaRiveratacostinexcessofonemilliondollarspermile.Justsouthoftheprojectareatheaccessroadwouldturnnorthandcrosstheriverapproximatelyonemilesouthwestoftheconstructioncamp.Theaccessroadwouldbe20to30feetwideandrequirea100-footwidestripofright-of-way.SomeimprovementstotheAlaskaRailroadrailbed,andhighwaysandbridgestoTalkeetnamaybenecessarytoprovideforconstructiontraffic.Riverniversion.Adiversiontunnell,500feetlongwouldbeprovidedthroughtherightabutment.Upstreamanddownstreamdiversioncofferdamswouldberequired,havingatotallengthofapproximately1,500feet.Camp.Thecampwouldbelocatedinarelativelyflatareaabout4.5milesdownstreamoftheimmediateprojectworkareaandreservoir,coverl.ngatotalofabout100acresofland.Thecampwouldhavetobeeitherprotectedfromfloodingbydikes,orrelocated,iffuturestudiesindicatefrequentfloodingattheconfluenceoftheTalkeetnaandSheeprivers.OnsiteRoads.Onsiteroadswouldconnecttheconstructionareas,borrowareasandquarry,camp,etc.withthemainaccess.Minimalfoundationexcavationorstabilizationmayberequired.Theroadswouldhaveaminimumwidthof20to30feet.ImperviousBorrow.Animperviousborrowcapacityofapproximately2.4x106cubicyardswouldberequired,andmaybeobtainablefromborrowexcavationsalongtheriver.However,shouldtheareaproveunsatisfactoryforuseinimperviouszonesofthedam,borrowmayberequiredfromhigherelevationsabovethefloodplain.Exploitationoftheseareaswouldinvolvemoredifficultandcostlyonsiteroadconstruction,steepercutslopes,andpossiblestabilityproblems.PerviousBorrow.Borrowcapacityofapproximately16.9x106cubicyardswouldbeneeded.Allperviousborrowwouldbetakenfromtheriverand.J)J453410/68408206-8 :-1riverbankswithinthereservoirarea,andto3+milesdownstreamofthedamalignment.Sufficientperviousborrowappearstobeavailable.'JRockQuarry.excavations.Relocations.AllrockneedscouldpossiblybesatisfiedthroughrequiredHowever,aminimumquarrywouldbeprovided.NorelocationswouldresultbecauseoftheKeetnaproject.],1]Transmission.Transmissionlines(Exhibit2)wouldextendfromtheKeetnapowerhousesubstation,alongtheeastandsouthsideoftheTalkeetnaRivertotheAnchorage-FairbanksIntertieeastofthetownofTalkeetna.Thelengthofthelinewouldbeabout11miles,andrequirea100footwide'right-of-wayalongitsalignment.6.1.3.2DamEmbankment.Theassumeddesignwouldincorporateazon~drolledfillconsistingofacentral,imperviouscore,andpervious/rockfillshells.Itwouldhavea30-footwidecrest,acrestlengthof1,200feet,amaXl.mumheightof415feet,anq,abasewidthofabout2,300feetatitsmaximumsection.Foundation.Deepexcavationsofapproximately70to100feetwouldhavetobemadethroughoutthedeepestpartofthevalley.Thedepthofexcavationwouldbereducedtoabout25feetattheabutments.Excavationwouldbebeneathboththecoreandtheshellsofthedam.]1jDisposal.area,andWastedisposalwouldbeupstreamofthedamwithinthereserVOl.rtoanelevationbelowtheminimumanticipatedreservoirlevel.Powerhouse.Typicalpowerhousedesignandconstructionproceduresareanticipated.Reservoirwaterwouldbetransportedtothe100MWsurfacepowerhousebya1,300footlongpowertunnelthroughtheleftabutment.A453410/68408206-9 1J,~]1J:Jnominallengthofdischargechannelmayberequiredtotransportdownstreamflowtotheriver.Spillway.Thespillwaywouldbeconstructedinanexcavationthroughtheleftabutmentrock.Nominalapproachandtailracechannelexcavationmayberequired.Reservoir.Thereservoirsurfaceareawouldbe5,500acres.Asmuchas65,000acre-feetofsedimentcouldaccumulateinthereservoirina50-yearperiod,possiblyresultinginthedevelopmentofmudflatsintheupstreamreachesofthereservoir.Schedule.Noschedulingproblemsareforeseenatthistime.6.1.4SnowDamandReservoir6.1.4.1General.TheprojectlocationandlayoutarepresentedonExhibits1and6.Access.AccesstothesitewouldbefromtheSewardHighwayataP?intapproximately4milesnorthoftheprojectarea.Theaccessroadwillbe20to30feetwide,andrequirea"100footwideright-of-way.However,improvementstotheSewardHighwayandrailbedmaybenecessarytoprovideforconstructiontraffic.RiverDiversion.Adiversiontunnel(2,000feetlong)wouldbeprovidedthroughtheleftabutmentifrockconditionspermit.Adiversiontailracechannel(200to300feetinlength)andupstreamanddownstreamdiversioncofferdamshavingatotallengthofapproximately750feetwouldberequired.453410/68408206-10 Camp.Thecampwouldbelocatedinarelativelyflatareaabout1.5mileswestoftheimmediateprojectworkareaandreservoir,coveringatotalofabout100acresofland.OnsiteRoads.Onsiteroadswouldconnecttheconstructionareas,borrowareasandquarry,camp,etc.withthemainaccess.Minimalfoundationexcavationorstabilizationmayberequired.Theroadswouldhaveaminimumwidthof20to30feet.ImperviousBorrow.forconstruction.Approximately0.6x106cubicyardswo~ldberequiredJPerviousBorrow.Aborrowcapacityofapproximately5.8x106cubicyardswouldbeneeded.Allperviousborrowwouldbetakenfromtheriverandr1verbankswithinthereservoirareaanddownstreamtotheconfluenceoftheSnowandSouthForkSnowRivers.RockBorrow.Allrockneedscouldpossiblybesatisfiedthroughrequiredexcavations.However,aminimumquarrywouldbeprovided.Relocations.NorelocationsareinvolvedwiththeSnowproject.Transmission.Transmission(Exhibit2)wouldbeapproximately87milesnorthfromtheSnowpowerhousesubstation,generallyfollowingthealignmentoftheAlaskaRailroad,toAnchorage,whereitmayormaynotbejoinedwiththeAnchorage-FairbanksIntertie.Thelengthofthenewline(costestimatedtobe$700,000),requiringa100-foot-wideright-of-way,wouldbeapproximately4miles(50+acres),fromthesubstationtotheexisting-.transmissionfacilitiesconnectingAnchoragetoSeward.Theapproximately83milesofexistinglineswouldhavetobeupgradedtoaccommodateSnowenergygeneration.453410/6840820.6-11 '16.1.4.2DamEmbankment.Theembankmentwouldbeazonedsectionconsistingofacentral,imperviouscore,andpervious/rockfillshells.Itwouldhavea30footwidecrest,acrestlengthof820feet,anestimatedmaximumheightof310feet,andabasewidthofabout1,750feetatitsmaximumsection.Additionalfreeboardmayberequiredtoallowforreservoirstorageofglacieroutburstfloodswithoutovertoppingthedam.Foundation.Between20feetand80feetofmaterialwouldhavetobe"1:J.Jexcavatedthroughoutthefoundation,withthedeepe~excavationsoccurringnearandintheriverchannel.Foundationexcavationwouldbebeneathboththecoreandshellsofthedam.Disposal.Wastedisposalwouldbeupstreamofthedamwithinthereservoirarea,andtoalevelbelowtheminimumnormalreservoirlevelanticipated.Powerhouse.Reservoirwaterwouldbetransported'tothe63MWsurfacepowerhousebya10,000foot,longpowertunneland2,000footlongpenstock.Thepowertunnelwouldbelocatedthroughtherightabutment.A2,000footlongdischargechannelwouldtransportflowbacktotheSnowRiver.Penstockconstructionwouldrequirea50footwideright-of-way.Noproblemswouldoccurduringdesignandconstructionofthetunnelprovidedtherockalongthepowertunnelalignmentisofacceptablequality.Thiscouldbeverifiedonlybyextensiveandexpensiveexploration•Spillway.Thespillwaywouldbeconstructedl.nashallowvalleyal:'-thesouthernendofthereservoirapproximately1milesoutheastofthedam.Nominalapproachchannelexcavationmayberequired;3,200feetoftailracechannelexcavationwouldbenecessary.Unusualproblemsassociatedwiththespillwaywouldincludetheneedtoprovidesufficientcapacit;ytoallowstorageofglacieroutburstfloodswithoutovertoppingthedam,anddissipationofthesurchargedreservoirwithoutcausingfloodingdownstream.1453410/68408206-12 oftheproject.projectcost.Theincreasedspillwaysuewouldmateriallyaddtothe1J-]Reservoir.Thereservoirsurfaceareawouldbe3,200acres.PortionsofCltheParadiseValleytrailandLowerParadiseLakewouldbeinundated.ThepotentialforglacialoutburstfloodsontheSnowRiverwouldnecessitatespecialoperatingprocedures,alarger(orpossiblyemergency)spillway,additionalprojectfreeboard,andpossiblyotherprotectivemeasures.Schedule.Therearenoschedulingproblemsforeseen.6.1.5ChakachamnaDamandReservoir6.1.5.1General.and7.TheprojectlocationandlayoutareshownonExhibits1,]Access.Accesswouldbetowithinapproximately15milesoftheprojectsitealongexistingroadsfromTyonek.Theseroadswouldrequ1reimprovementandpossiblewideningpr10rtothestartofcQnstruction.AccessfromAnchoragetoTyonekwouldbeeitherbywaterduringthenavigablemonths,byaroadconstructedbetweenTyonekandAnchorage,orboth.PortimprovementsatTyonekwouldbenecessary.Accessfromthe,JexistingroadsfromTyonekwouldbeextendedtoboththedamareaandtothepowerhouseareabytwo20to30footwideroadshavingatotallengthofapproximately24miles.A100footwideclearedright-of-waywouldberequiredalongtheentirelengthofnewaccessroad(290acres).RiverDiversion.Noparticulardiver&ionproblemsareforeseenastheriverwouldflowunimpededduringspillwayconstruction;thespillwayareawouldbecofferdammedtopreventfloodingduringconstruction.Followingspillwayconstruction,constructioncofferdamswouldberemovedfromaroundthespillway,andtheChakachatnaRiver'divertedthroughthecompletedstructure453410/68408206-13 -]whilethedamisconstructed.Thetotallengthofcofferdamrequiredfrombothstagesofconstructionwouldbeabout800feet.Camp.Campswouldbelocatedinrelativelyflatareasoutsideoftheinunediateprojectworkareas,coveringacombinedtotalofabout100acresofland.OnsiteRoads.Onsiteroadswouldconnecttheconstructionareas,quarry,camp,etc.withthemainaccess.Minimalfoundationexcavationorstabilizationmayberequired.to30feet.Theroadswouldhaveaminimumwidthof20ImperviousBorrow.requiredexcavations.ImperviousborrowwouldprobablybeobtainedfromPerviousBorrow.CoarsegrainedmaterialswouldbeobtainedfromtheChakachatnaRiverchannel,orprocessedfromcrushedquarrystone.RockQuarry.Allrockwouldbeobtainedbydevelopingonsitequarries~nreasonableproximitytothedam.Relocations.Norelocationswouldberequired.theAnchorage-130miles,andestimatedtobeXransmissionlines(Exhibit2)wouldextendfromtheandacrosstheChakachamnapowerhousesubstation,approximatelydueeastKnikArmtoAnchorage,wheretheymayormaynotjoinFairbanksIntertie.Thelengtho·fthelinewouldbeaboutrequirea200-foot-wideright-of-way(3150acres)atacostTransmission.II1J$60,000,000.6.1.5.2DamEmbankment.Theembankmentwouldbeazonedsectionconsistingofacentral,imperviouscore,andpervious/rockfillshells.Itwouldhavea20453410/68408206-14 1J1J]1J1JIjJfootwidecrest,acrestlengthof600feet,amax1mumheightofabout30feet,andabasewidth'ofabout200feetatitsmaximumsection.Foundation.Someexcavationoffinegrainedunconsolidatedand/orfrozenoverburdendepositswouldberequiredbeneaththecoreandshellsofthedam.Disposal.WastedisposalwouldbeupstreamofthedamalongthenorthbankoftheChakachatnaRiverandLakeChakachamna.Wastewouldbegradedtopresentaneat,welldrainedsurfacesinceitwouldbeexposedmostofthetime.Powerhouse.ChakachamnaLakewaterwouldbetransportedtothe330MWundergroundpowerhousebya10-mi1elongpowertunnelwhichtapsthesoutheastrimofthelake.A100-footlongdischargetunnelwouldtransportflowfromthepowerhousetotheMcAr~hurRiver.Potentialengineeringproblemscouldexistiftherockqualityalongthetunnelalignmentispoor,\.orifhighin-situstressesexistintherockattheundergroundpowerhouselocationduetothenearbypresenceoftheLakeClark-CastleMountainfault.Thesepotentialproblemswouldnecessitateextensiveandexpensivesubsurfaceexploration.Spillway.Thespillwaywouldformtherightabutmentofthedam..A210footapproachchannelwoulddischargedirectlyintotheChakachatnaRiverwithoutneedfortailracechannelexcavation.FishPassageFacility.The'fishpassageinletfacilitywouldbelocatedapproximately350feetsouthwestofthespillway.A930-foot-Ion~approachchannelwoulddirectlakewatertotheinletfacility,whereitwouldbeconnectedbya3,000foottunneltooutletfacilitiesdownstreamonthesouthbankoftheChakachatnaRiver.Theengineeringfeasibilityandcostofsuchafishpassagefacilitywoulddependupontheadequacy'oftherockqualityalongthetunnelalignment.453410/.68408206-15 ~--I'J]I.J,jReservoirCharacteristics.ChakachamnaLakewouldprovidethenecessaryreservoirstorageandwouldhaveamaximumoperatinglevelofelevationof1,155feetandaminimumoperatinglevelofelevation1,083feet.Schedule.Roadwayconstructionandimprovements,andTyonekdockfacilitiesimprovementswouldhavetobecompletedpriortoprojectconstruction.Winterboattransportrestrictionswouldnecessitateschedulingthemajorityofsupplyandequipmentdeliveriestothesiteduringthemonthsoftheyearthatarenavigable.AccesstoTyonekbyairwouldbeavailableyear-round.6.1.5.3.ProjectRisk.Projectriskwasdiscussed1ndetailbyBechtel(1983).Itwasfoundthattheprojectwouldbeattendedbyanumberofrisksassociatedwiththephysicallayoutoftheprojectstructuresandnaturalphenomenaoccurringwithinandadjacenttotheprojectarea.LakeTapping.Ithasbeenpresumedthatalocationcanbedefinedbyexplorationwheresuitablerockconditionsforlaketappingexist,baseduponobservedrockconditionsabovethelakewaterlevel.However,theexactphysicallocation,designrequirementsanddetailswouldrequireasignificantamountofdesignphasesubsurfaceexploration.TunnelAlignmentRockConditions.Asmentionedpreviously,bedrockcharacteristicsastheymayaffecttunnellingconditionshavenotbeenstudied.H~ghpressuregroundwaterandadverserockconditionsarefactorswhichcouldaddtothecostofconstructingthepowertunnel.Thegreatdepthofrockcoverpreventsexplorationattunnelgradeexceptnearthetwoends,and1cecover1ng25%of.thealignmentdoesnotpermitobservationofthesurfacerock.Intheabsenceofexplorationoversomuchofthetunnellength,morewaterathighpressure,andmorehighlystressedrockthananticipated,mightbeencounteredduringconstructionoftheJ453410/68408206-16 ]]]]'IJtunnel.Inthatcase,theconstructedcostwouldbegreaterthancurrentestimatesindicate.UndergroundPowerhouseSite.Thelocationofthepowerhouseshouldfollowdesignlevelexploration,constructionofanexploratoryadit,andlaboratoryandin-situmeasurementoftheengineeringpropertiesoftherock.Thepossibilityexiststhathighin-siturockstressesmayoccurneart?eundergroundpowerhouseexcavationduetothenearbypresenceoftheLakeClark-CastleMountainfault.BarrierGlacier.BarrierGlaciercontainsChakachamnaLakeandcontrolsitswaterlevel.NoevidenceofsurginghasbeenreportedinBarrierGlacier.However,ithasgonethroughvariouscyclesofadvanceandretreatinrecenttime,andmayreasonablybeexpectedtocontinuetodosointhefuture.Theextenttowhichsuchcyclesmightaffectthelakelevel,andthustheamountofactivestorage,whichwould,inturn,affectpowergeneration,cannotbepredictedwithcertainty.BlockadeGlacier.BlockadeGlacierisfedbylargesnowfieldshighonthesoutherlyslopesoftheChigmitMountainstothesouthofMcArthurcanyon.TheglacierimpoundsBlockadeLake,which1SthesourceofoutburstfloodsthatdischargeintotheMcArthurRiver.ThepresentterminalmoraineofthenortheasterlyflowinglobeofBlockadeGlacierlieswithinabout1.5milesofthemouthoftheMcArthurCanyon."IftheBlockadeGlacierweretoadvanceduringthelifeoftheproject,it1SconceivablethatthemorainalmaterialcouldalsoadvancetowardtheMcArthurRiverandcausetheriverbedtoaggradedownstreamofthemouthofthecanyon.Thiscouldcauseariseintailwaterleveltooccuratthepowerplantsitewiththeextremeconsequencebeingafloodingofthepowerhouse.TheremotepossiblitythatclimatologicalchangesandconsequentchangesinmassicebalancemaytriggersurgingoftheBlockadeGlacierduringthelife453410/68408206-17 ]JJ]J]1.J1Joftheprojectcannotbeforecastedorevaluatedwithanydegreeofcertainty.SurgingoftheBlockadeGlacierisconsideredtobethemostlikelymechanismthatcouldbeexpectedtoproduceanadvanceoftheglacierthatmightimpactontheproposedMcArthurpowerhousesite.McArthurGlacier.Theterminusof'thisglacierliesintheMcArthurcanyonabout5milesupstreamfromtheproposedpowerhousesite.Anadvanceoftheglacieroverthatdistance,althoughremotelypossible,wouldendangerthetailracechannelandportalsofthetailracetunnelandaccesstunneltotheundergroundpowerhouse.Mt.SpurrVolcano.ThesummitofMr.Spurrliesabout7milesnortheasterlyfromtheoutletofChakachamnaLakeand7.5milesfromtheproposedpowerintakesite.Theintakecouldbelocatedfurthertothewestandawayfromthevolcano,butthiswould1ncreasethelengthandcostofthepowertunnel,andalsothedifficultyandcostofaccesstotheintakesitealongtheprecipitousmountainslopesonthesouthsideofthelake.Mt.Spurrisregardedbysomevolcanologiststobesimilar,1nseveralrespects,toMt.St.HelensintheStateofWashingtonwhoseMay18,1980eruptiondevastaEeda200-square-milearea.Presenttechnologyforpredictingvolcanicactivityislimitedtotheshortterm,andthere1SnowaytoforecastwhenMt.Spurrwillnexterupt,orwhetheritmighteruptduringthelifeoftheproject.Mt.Spurr'slastmajoreruptionoccurredonJuly9,1953.Acatastrophicblast,suchasoccurredatMt.St.Helens,1Sarareevent,butofcoursecannotberuledout.ThegeneraldirectionofafutureeruptionisexpectedtobedirectlyacrossanddowntheChakachatnaValley.TheproposedpowerintakesiteonLakeChakachamnacouldbeanareaofashdeposition.Itcouldalsobeaffectedbyalargelandslideormudflow,orbyhotblastsfrompyroclasticflows,ifsuchweretooccur.Theevidenceisthatthesehaveoccurredinthepast,particularlyintheChakachatnaValley.J453410/68408206-18 :J]]1J1JWhilefutureeventssimilartothe1953eruptionwouldprobablyhavelittleeffectontheabilityofthepowerfacilitiestocontinueinoperation,they.couldreadilyputthefishpassagefacilitiesoutofservice.Anothermud-flowcoulddamtheriverbelowCraterPeakthuscausingittobackupandfloodtheproposedstructureatthedownstreamendofthefishpassagefacilities.ThereducedflowintheChakachatnaRiverwouldnothavethesameeros~vepowertocutitswaydownthroughthedebrisdamanditcouldwellbecomepecessarytomechanicallyexcavateachannelthroughthedebristolowerthewaterlevelandreturnthefishpassagefacilitiesintooperation.AcatastrophiceventoftheMt.St.Helenstype,ifdirectedtowardsthelakeoutletandintakestructure,couldhaveveryser~ouscon~equencesandpossiblyburyboththeupstreamanddownstreamendsofthefishpassagefaciIities,andthepowerintake,beneathamassivemudflow•Thetremendousamountsofheatreleasedbypyroclasticashflowscouldmeltice~nthelowerpartsoftheBarrierGlacierandinterferewiththeglacier'sabilitytocontinuetocontainLakeChakachamna.ThepowerhouseandassociatedstructuresinitsvicinitywouldprobablynotbesignificantlyaffectedbyvolcanicactivityatMt.SpurrbecausetheyareshieldedfromthedirecteffectsofavolcanicblastbythehighmountainsbetweentheChakachatnaandMcArthurvalleys.SeismicRisk.Thesitelieswithinazoneofhighse~sm~crisk.PotentialIseismicsourceswhichmayaffecttheprojectsitearethesubductionzonefaultsinthecrustalseismiczoneandseverevolcanicactivity.TheLakeClark-CastleMountainfault(crustalsource)andthemegathrustsegmentofthesubductionzoneareconsideredthemostcriticalwithrespecttopeakgroundaccelerationanddurationofstrongshakingatthesite.TheLakeClark-CastleMountainFaultisamajorregionalfaultthathasbeentracedforover300miles.Atleastonecrossingofthefaultbythepowe~transmissionlinecannotbeavoided;thiswillbeinthevicinityofthemouthoftheMcArthurCanyon.Thepowerhouseswitchyardalsowouldbeinthisvicinity.Thus,someofthetransmissiontowersandswitchyard453410/68408206-19 ]]]JI.J1JI_Jstructureswouldbesubjectedtoverystrongshaking1ntheeventofamajorearthquakeonthefaultneartheMcArthurCanyon.Undergroundstructureswouldprobably.belessvulnerabletodamagethansurfacestructures.Thestructurescanbedesignedtowithstandthestrongestlateralfqrcesexpectedtooccur,butitisnotpossibletodesignagainstsignificantdisplacementinthefoundationatanygivenstructuresite.Consequentlystructuresshouldnotbelocatedinthefaultzone.TheBruinBayFault1Soneofthemajorregionalfaults1nSouthcentral.Alaska.Inthevicinityoftheprojectsite,it1SinferredtooccurmoreorlessparalleltotheCookInletcoastlineabout20milessoutheastofthemouthpftheMcArthurCanyon.FourfeatureswhichmaybesignificanttotheprojecthavebeenidentifiedintheChakachatnaValley.ThesefeaturesincludefaultswhichmayoffsetHolocenedeposits(lessthanabout2millionyearsold);also,oneofthefeaturestrendstowardthesiteoftheproposedpowerintakestructure.Furtherstudyoftheprojectshouldincludeevaluationoftheageandextentoffaultingwhichisrelatedtothesefeatuhes,inordertobetterassessthepotentialforfaultdisplacementatornearprojectstructures.6.1.6WatanaDamandReservoir6.1.6.1General.TheprojectlocationandlayoutarepresentedonExhibits1and8.Access.AccesstotheWatanadamsitewillconnectwiththeexistingAlaskaRailroadatCantwellwherearailheadandstoragefacilityoccupying40acreswillbeconstructed.Thisfacilitywillactasthetransferpointfromrailtoroadtransport....FromtherailheadfacilitytheroadwillfollowanexistingroutetothejunctionoftheGeorgeParksandDenaliHighways(adistanceoftwomiles),thenproceedinaneasterlydirectionforadistanceof21.3milesalongtheDenaliHighway.Anewroad,41.61J453410/68408206-20 )1)jJmilesinlength,willbeconstructedfromthispointduesouthtotheWatanacampsite.Thisroadwillrequirea200footright-of-way.RiverDiversion.Diversiondoesnotpresentanyforeseeableproblems,baseduponexistingsubsurfaceexplorationinformation.Twodiversiontunnels(4,050and4,140feet~nlength)willbeprovidedthroughtherightabutment.Atotalcombineddischargechannellengthof500feetwillbeinvolved.Upstreamanddownstreamdiversioncofferdamshavingatotallengthofapproximately1,200feetwillberequired.Camp.Theconstructioncampwillbelocatedinrelativelyflatareasnorthandnortheastoftheimmediateprojectworkareaandreservoir,coveringatotalofabout200acresofland.Noparticularlocationproblemsareexpected.OnsiteRoads.Onsiteroadswillconnecttheconstructionareas,borrowareasandquarry,camp,etc.withthemainaccess.Minimalfoundationexcavationorstabilizationmayberequired.Theroadswillhaveaminimumwidthof20,to30feet.ImperviousBorrow.Imperviousborrowwillbeobtainedfromrequiredexcavationsandborrow.Borrowareascoveringapproximately900acresoflandwillbeprovided.PerviousBorrow;PerviousborrowwillbeprovidedbyborrowpitsalongtheDevilCanyon-Watanaaccesslink,andfromtheriverandriverbanks.RockBorrow.Aleftabutmentquarrysupplementedbytherequiredexcavations'willprovideforrockandaggregateneeds.Ir,JRelocations.project.NorelocationswillberequiredbecauseoftheWatanaTransmission.Transmissionlines(Exhibit2)wi11extendfromtheWatanapowerhousesubstationtotheGoldCreekswitchingstationwhereitwilljoin]J453410/68408206-21 _JtheAnchorage-FairbanksIntertie.Thelengthofthelinewillbeabout45miles,andrequirea300footwideright-of-way.Nospecialproblemsassociatedwiththetransmissionlineareforeseen.6.1.6.2DamEmbankment.Theembankmentwillbeazonedsectionconsistingofacentral,imperviouscore,andpervious/rockfillshells.Itwillhavea35footwidecrest,acrestlengthofabout4,100feet,amaximumheightof885feet,andabasewidthofabout4,000feetatitsmaximumsection.Nounusualproblemsassociatedwithdamdesignorconstructionareanticipated.Foundation.beneaththebedrock.Approximately110feetofmaterialwillhavetobeexcavatedcoreandshellsofthedamtoallowittobefoundedon]\---')IJ1__-l,.Disposal.Wastedisposalwillbeupstreamofthedamwithinthereservoirarea,andtoalevelbelowtheminimumnormalreservoir.Powerhouse.Reservoirwaterwillbetransportedtothe1,020MWundergroundpowerhousebythreeSOO-foot-longconcreteandsteeT-linedtunnelsthroughtherightabutment.A1,000-foot-longapproachchannelwilldirectwatertotheupstreamendofthetunnel,andl800-foot-longtailracetunnelswilldirectflowfromthesurgechamberdownsreamofthepowerhousetotheriver.Nounusualproblemsareforeseenbasedonexistingsubsurfaceexplorationdata.Spillway.Theservicespillwayandspillwayexcavationwillbeconstructed~nthesteep,rightabutment.Approachandtailracechannelexcavation(4,000linealfeet)willberequired.Nounusualproblemsareanticipated.453410/68408206-22 ]]JJ.1Reservoir.Thereservoirsurfaceareawillbe38,000acres.Schedule.Constructionaccessroadsandrailroadwillhavetobescheduledforcompletionpriortomobilizationsoasnottodelayconstruction.6.1.7DevilCanyonDamandReservoir6.1.7.1General.TheprojectlocationandlayoutarepresentedonExhibits1and8.Access.AccesstotheDevilCanyondevelopmentwillconsistprimarilyofarailroadextensionfromtheexistingAlaskaRailroadatGoldCreektoarailheadandstoragefacilityadjacenttotheDevilCanyoncamparea.Toprovideflexibilityofaccess,therailroadextensionwillbeaugnentedbyaroadbetweentheDevilCanyonandWatanadamsites.FromtherailheadfacilityatDevilCanyonaconnectingroadwillbebuilttoahigh-levelsuspensionbridgeapproximatelyonemiledownstreamofthedamsite.Theroutethenproceedsinanortheasterlydirection.AftercrossingTsusenaCreek,theroadcontinue$southtotheWatanadamsite.Theoveralllengthoftheroadis37.0miles.Theroadandrailroadroutemainlytraverseterrainwithgentletomoderatesideslopes,wherearight-of-waywidthof200feetwillbesufficient.Onlyinareasofmajorsidehillcuttinganddeepexcavationwillitbenecessarytogobeyond200feet.RiverDiversion.Adiversiontunnel(1,500feetlong)willbeprovidedthroughtheleftabutment.Adiversiontailracechannelwillberequired.Upstreamanddownstreamdiversioncofferdamshavingatotalcrestlengthofapproximately500feetwillberequired..Baseduponexistingsubsurfaceexplorationdatanodiversionproblemsareanticipated•.}453410/68408206-23 )]Camp.Thecampwillbelocatedinarelativelyflatareaabout2-milesdownstreamoftheimmediateprojectworkareaontheleftsideoftheriver.Atotalofabout100acresoflandwillbeutilized.OnsiteRoads.Onsiteroadswillconnecttheconstructionareas,borrowareasandquarry,camp,etc.withthemainaccess.Minimalfoundationexcavationorstabilizationmayberequired.Theroadswillhaveaminimumwidthof20to30feet.PerviousBorrow.Allperviousborrowwillbetakenfromther1verandr1verbanks,orfromtheborrowpitslocatedalongthema1naccessbetweenthedamsiteandGoldCreek.RockBorrow.Allrockneedscouldpossiblybesatisfiedthroughrequiredexcavations;aminimumquarrywouldbeprovided.]]]Relocations.project.NorelocationswillberequiredbecauseoftheDevilCanyon]]1~JTransmission.Transmissionlines(Exhibit2)willextendfromtheDevilCanyonpowerhousesubstation,parallelingthetransmissionlinesfromWatana,and.:jointheAnchorage-FairbanksIntertieattheGoldCreekswitchingstation.Thelengthofthelinewillbeabout10.5miles,andwillnotrequireaspecialright-of-waybecauseoftheWatanatransmissionwhichwillthenexist.6.1.7.2DamStructure.TheDevilCanyonDamwillbeathin,doublecurvatureconcretearchdam.Noproblemswithdamdesignandconstructionareanticipatedatthistime.Foundation.Thedamwillbefoundedonsoundbedrock.Anexcavationdepthofapproximately20to40feetwillberequiredtoattainfoundationlevel.453410/68408206-24 ]J]]J.JDisposal.Wastedisposalwillbeupstreamofthedamwithinthereservo~rarea.Itwillbeplacedbelowtheminimumnormalreservoirlevel.Powerhouse.Reservoirwaterwillbetransportedtothe600MWundergroundpowerhousethroughtherightabutmentbya250-foot-longapproachchanneland900-foot-longconcreteandsteellinedpowertunnels.A6,800-foot-longtailracetunnelwilldirectwaterfromthesurgechamberdownstreamofthepowerhousetotheriver.A200-foot-longexcavatedchannelwillbeatthedownstreamendofthetailracetunnel.Noparticularproblemswithdesignorconstructionareforeseenatthistimebasedonavailablesubsurfaceinformation.Spillway.Thespillwaywillbeincorporatedintothedam.Reservoir.Thereservoirsurfaceareawillbe7,800acres.Schedule.Nounusualschedulingproblemsareanticipated.6.2ComparisonofNon-SusitnaAlternativeProjectswiththeProposedProject6.2.1SummaryandConclusions.DevelopmentoftheWatanaandDevilCanyonsiteswouldresult~nlesspotentialengineeringdesignandconstructionproblemsthanthefivealternatives-Browne,·Johnson,Keetna,Snow,andChakachamna.ThemajorproblemswiththealternativesincludethemaSS1ve•amountsofrelocationinvolved,andthepossibledifficulty~nfindingimperviousborrowmaterial.Sedimentationandfloodingarealsopotentialproblemswiththealternatives.Table1summarizestheengineeringassessmentsforeachalternativeandadditionaldescriptionsareprovidedbelow.453410/68408206-25 6.2.2ComparisonsAccess.Theredonotappeartobeanyunusualaccessdifficultiesforanyofthehydroalternatives,exceptforChakachamnaandWatana.Watanaaccesswouldbelongandexpensive,involvingbothrailandroadways,Chakachamnaaccesswouldnotonlybelongandexpensive,butwouldalsoinvolvemuchimprovementtoexistingfacilities.RiverDiversion.ofthesites,tunnelling.TherearenotanyapparentdiversiondifficultiesforanyprovidedthatbedrockisofacceptablequalityforCamp.Withtheinformationavailable,allcamplocationsappearacceptable.TheKeetnacampsitemaybesubjecttoflooding,dependinguponthehydraulicconditionsattheconfluenceoftheTalkeetnaandSheeprivers.Dikeprotectionmaybenecessary.]On-SiteRoads.evident.Nounusualdifficultiesatanyoftheprojectsitesare~lI.JJImperviousBorrow.ObtainingsufficientquantititesofimperviousmaterialscouldbeaproblemattheJohnsonandKeetnasites.Additionalon-siteroads,involvingconstructiononsteepslopestoga~naccesstohigherelevationswhereimperviousmaterialmaybemorereadilyavailable,~sapossibility.PerviousandRockBorrow.Sufficientperviousandrockmaterialshould~eavailableatallprojectsites.Relocations.TheBrowneandJohnsonsiteswouldrequireasubstantialamountofrelocationofpublictransportation.facilities,transmissionlines,roadmaintenancefacilities,townsandcommunities,andothermiscellaneousfeatureswhichwillbeinundateduponreservoirfilling.Noneoftheothersitesevaluatedrequireanyrelocations.453410/68408206-26 ):JJTransmission.Johnson,Snow,andChakachamnasitesareremotelylocatedwithrespecttotheAnchorage-FairbanksIntertie,andwouldrequirelongtransmissiontrunklinestoconnecttotheIntertie.Dam.Onapreliminarybasis,noneofthedams,whetherembankmentorconcrete,appeartopresentanyunusualdesignorconstructionproblems.Foundation.Allofthesit~swouldrequ~resubstantialfoundationexcavationtoremovepervious,loose,andpossiblyfrozenunconsolidatedmaterialsfromtheriverchannelsandimmediatefloodplainoneithersideofther~ver.Chakachamna,beingalowdam,mayormaynotrequiresuchextensivefoundationpreparation.Disposal.Disposalcanbehandledacceptablyatallsites.Powerhouse.Thosesiteswhichwillincludeeitherapowertunneloranundergroundpowerhousemayrequ~.respecialdesignandconstructionconsiderationsdependinguponthequalityoftherockalongthestructurealignment.TheChakachamnapowertunnel,whichisapproximately10mileslong,wouldrequireverydetailedgeologicinvestigationandstudybecauseofitsgreatersusceptibilitytoproblemscreatedbychangesingeologyalongitslength.JSpillway.Nounusualdesignorconstructionproblemsareforeseenatany.oftheprojectsites.Reservoir.SpecialengineeringconsiderationswouldberequiredattheBrowne,Johnson,Keetna,andSnowsites.BrowneandJohnsonreservoirswillnecessitateextensiverelocations.JohnsonandKeetnareservoirswillbeparticularlysusceptibletosedimentationandthedevelopmentofmudflats,whichwillresult~nloststoragecapacityandthereforewinterenergygeneration.TheSnowsiteisperiodicallysubjectedtoglacialoutburstflooding,whichwillrequirespecialdesigntreatmentinvolvingincreasedJ,J453410/68408206-27 \III]IJlJprojectfreeboard,increasedspillwaycapacityoremergencyspillways,orareducedoperatingpoollevel.Schedule.TheBrowneandJohnsonprojectswouldrequ~reproperschedulingtoenablerelocationoftransportationfacilitiesfarenoughinadvanceofprojectimplementationsothatnointerruption~nthetransportationfacilitiesoccurs.ImprovementstoexistingaccessfacilitiesforChakachamna(Tyonekdockfacilities,existingroads,etc.)wouldhavetotakeplacesufficientlyinadvanceofmobilizationsoasnottocausedelaysinthework.6.3TransmissionLinesBoththeSusitnaprojectandthenon-SusitnaalternativeswouldutilizethetransmissionintertieconnectingAnchorageandFairbanks.Inaddition,therewouldbetheindividuallinksbetweenprojectsandtheIntertie.Thetransmissionfacilitieswouldinclude370milesofoverheadtransmissionline,4milesofsubmarinetransmissionline,switchyards,andsubstations.Theright-of-way(ROW)acreageforthenon-Susitnahydroelectricsites~sapproximately3000acresmorethantheProposedProject(13,790acrescomparedto10,600acresforSusitna).ThesetotalROWacreagefiguresarebasedonapproximateROWwidthsforvar~ouslinevoltagesandonlinelengths,includingtheintertieupgradebetweenFairbanksandAnchorage.453410/68408206-28 'J'I7.0EnvironmentalEvaluationofAlternativeSites7.1BackgroundInthissection(7.0),thePowerAuthoritysupplementsandevaluatestheenvironmentalinformationthatFERCpresentedintheDEISwithinformationthathasbeenobtainedorbecameavailablesincetheinitialscreeningstudy.Thissectionispresentedinthefollowingmannertoassistintherev~ewofpotentialenvironmentalimpacts.InSection7.2,adescriptionofenvironmentalcomponentsofeachnon-Susitnasite(Johnson,Browne,KeetnaSnow,andChakachamna)ispresented.Includedinthisdescriptionisadiscussionconcerningpotentialimpacts(primarilytohumanresources,terrestrialresourcesandaquaticresources)ateachsite.InSection7.3,comparisonsaremadeamongthesites.Finally,in,Section7.4,asummaryandconclusionsarepresentedconcerningthepotentialenvironmentalconsequencesofthenon-Susitnahydrogenerationscenario.-7.2SiteAnalysis7.2.1JohnsonSite7.2.1.1SocialSciencesSocioeconomicsThecommunitiesthatwouldmostlikelyexperiencesocioeconomicimpactsfromdevelopmentoftheJohnsonsiteincludeTok,DeltaJunction,Tanacross,DotLake,andTheLivingWord(acommunitylocatedonDryCreek)(seeExh~bit1).ThemostseriousimpactwouldbetheinundationofDotLakeandTheLivingWord,causingthedisplacementofallresidentsfromtheirhomes,socialsettings,andsourcesoflivelihood.Itisassumedthatthecostsof453410/78408207-1 J.~]:JJrelocatingboththesecommunitiestoothersuitablesiteswouldbebornbytheApplicant.DotLakewithapopulationofapproximately50people,isaNativecommunitysettledinthelate1940'swhoseresidentsareprimarilyAthabaskans(Martin1983).Somenon-Athabaskanshavemoved.intothecommunityinthelasttenyears.Hunting,trapping,fishing,andplantgatheringareveryimportanttoresidents,primarilyduetothelimited,unreliable,andtemporarynatureofwageemployment(Martin1983).TheseriousnessofDotLake'spossiblerelocationisunknownsinceinformationregardingtherelocationandadjustmentofAlaskanNativecommunitiestonewplacesduetodamconstruction~snonexistant.Whatisavailable,however,~sextensiveresearchontheeffectsofdisplacementdueto'hydroprojectsinAfrica(Scudder1971and1977),relatedAlaskanstudieswhichfocusonrelocationofNativecommunitiestointernmentcampsduringWorldWarII,andstudiesontherelocationorconsolidationofanumberofcommunitiesaroundregionalschoolsorotherserv~ces.Eventhoughthesestudiesdonotaddressthesituationwhichcouldar~seatDotLake,manyeffectsforthoseplacesstudiedhavebeennegative.TheLivingWordisasmallnon-Native.religiouscommunityofapproximate.ly200peoplelocatedonDryCreekwhichwasfoundedintheearly1970's.Thiscommunityisanincorporated,non-profitcorporationdependentonfarming,timbersales,andservicesprovidedtonearbytowns.Itsinundationwouldcreateseriousconsequencesforresidents(Guinn1984)sincethecommunitywouldnolongerexistandresidentswouldhavetorelocateandreestablishtheirsourcesoflivelihood,theirhomesandoverallpatternsofinteractionwitheachotherandthesurroundingenvironment.Tok,anunincorporatedtownprovidingservicesfortouristsandothertrafficalongthe.AlaskaHighway,hadapopulationof750residentsin1980(FERC1984).DeltaJunction,alarger,incorporatedcommunity'witha1982populationof1,044(FERC1984),providesfullcommunityservicesthatincludeafirestationandhealthcenterandisalsotourist-oriented.453410/78408207-2 :J'1'1j:])J1~J],J]JAprojectedpopulationinfluxof1,300personsduringthepeakconstructionperiodwouldnearlydoublethepopulationoftheTok-DeltaJunctionareacausingbothcommunitiestoexper~enceseveresocioeconomicimpacts.Thisnumberreflectsonlytheconstructionworkforceforthedamandnottheconstructionorrelocationofroads,railroads,andtransmissionlines.Therefore,theinfluxwouldprobablybegreaterthan1,300.Sincethemajorityofinmigrantswouldreside~nTokandD~ltaJunction,about400newhouseswouldberequired.Inaddition,commt;tnityservices;wouldhavetobeexpandedconsiderably.Commercialoperationswouldalsorequireexpansionandnewoneswouldprobablybeopened.Thebenefitsoftheseexpansions~ightbetemperedbyadecreaseintherural,undevelopednatureoftheareaandachangeinthequalityofthesettingforcurrentresidents.Tanacross(1982populationof117)isaNativecommunitylocatedbetweenTokandtheJohnsonsite'(FERC1984).Thecommunitywasincorpora'tedinMay1980andtheland~sintheprocessofbeingconveyedfromtheregionalcorporationtothevillagecorporationandthentoindividuals.Projectdevelopmentcouldresultinser~ousimpactstothiscommunityduetoculturalconflictsandinterferencewithsubsistenceactivities.TheJohnsonprojectwouldalsoinundatealodge,threegravelpits,ahighwaymaintenancestation,atelephoneline,twostream-gagingstations,portionsoftheAlaskaHighwayandapipeline,andairstripsatDotLakeandTheLivingWord.Again,itisassumedthatthecostsofrelocationwouldbebornbytheApplicant.LandUseTheareainandaroundtheJohnsonsite~sprimarilyforest,wildlifehabitat;andrecreationlandwithisolatedsettlements,mineralandgravelextractionareas,andtransportationandutilitycorridors.Seasonalusesoftheareaincludesporthuntingandfishingandsubsistenceactivities.453410/78408207-3 J-1_JjJjTheseuseswouldbegreatlyimpactedbythe94,500acrereservo~rcreatedbythedamandbyaccesstonewareasopenedupbyroads,transmissioncorridorsandthere-routingofportionsoftheexistinghighway>andpipeline.That~s,muchlandwouldbelosttohuntingwhileatthesametime,someareaswouldexperiencenewhuntingpressure.Additionally,theinundationofportionsoftheexistinghighwayandpipeline,ahighwaymaintenancestation,threegravelpits,twogagingstations,atelephoneline,andthecommunitiesofDotLakeandTheLivingWord,wouldalsoresultinseverelandusechangesandimpactsresultingfromtherequiredrelocationoftheseroutesandfacilities.Moreover,s~ncelandownershipwithintheprojectareaiscomplexandincludesStateforestlands,Nativelands,andprivatetractsacquiredthroughtheStateofAlaska'slanddisposalprogram,theacquisitionofaccessandinundationrightsthroughpurchasesoreasementscouldposeproblems.CulturalResourcesNohistoricorarcheologicalsitesarecurrentlyknownattheJohnsondam-siteorwithintheresultingimpoundmentarea.However,thisreflectsthelackofsurveysconductedinthearearatherthanalackofculturalresources.ThegeneralgeographicsimilaritiesbetweentheJohnsonandProposedProjectareassuggeststhattheJohnsonsite,ifsubjecttothesamelevelofsurveyastheProposedProjectarea,wouldbefoundtocontainalargenumberofculturalresourcessites.Constructionandoperationalimpactscanbe-expectedtobeofthes~metypeasthoseassociatedwiththeSus·itnadevelopment.Mitigationmeasureswouldalsobequalitativelysimilar,withananticipatedemphasisondatarecovery(salvageexcavation)fromsignificantsiteswithindirectimpactareas.RecreationTheTananaRiverisproposedbytheStateasamultiple-user~ver.Thisproposalrecommendsthatapproximately300feetbeyondeachriverbankberetainedinpublicownership(AlaskaDepartmentofNaturalResources(ADNR)453410/78408207-4 11983).GuidelinesunderthisclassificationallowforlimiteddevelopmentsuChascabins,agriculture,andtimberharvest,right-of-wayandutilitycorridors.TheTananaRiver~sheavilyusedforprivateandcommercialriverboating.,primarilyinthelowerriver.AcharterboatserviceislocatedatDotLake.TheTananaRiveralsosupportsamoderatelevelofsportfishingwithintensivefishingoccurringinanumberofsmalllakesinthearea(Martin1983).LakeGeorge,locatednortheastofthedamsite(Exhibit3),isused]]li)forrecreationalboatingandfishing.Lowlandsalongtherivercorridorsupportintensivesmallgamehuntingwhileintensive1./biggamehuntingoccursthroughoutthegeneralprojectarea(ADNR1984a).Therearemanymultiple-usetrailsthroughoutthearea.ThetrailstoKnobHillandRobertsonRiverarerecommendedbytheADNRforprotectionfromincompatibleusesandvisualimpacts(ADNR1983).Developedrecreationisfocused'primarilyonpubliccampgrounds,waysides,lodges,andservicefacilitiesorientedtowardsrecreationistsandsight-seerstravelingdowntheTananaValleyontheAlaskaHighway.Sightseeingintheprojectareaisorientedacrossthe.projectsitetowardsviewsoftheWrangellMountainsandwildlifeviewinginthevalley._.JIJ1./DesignationsofintensiveandmoderatearedefinedbyADNR(1982)asfollows:Intensive-areasidentifiedbyboththeAlaskaDepartmentofFishandGame(ADF&G)andpersonalinterviews.ModerateareasidentifiedonlythroughpersonalinterviewsorbyADF&G.453410/78408207-5 1I-1~I'.•1RecreationimpactsresultingfromtheJohnsonprojectwouldinclude:lossof94,500acresusedforhuntingandfishing;lossofrecreationalboatingandrivertransportation;andinundationofatleast23milesoftheAlaskaHighwaywithassociatedwildlifeviewingareas,viewpoints,aswellaslossofrecreationsupportfacilitiesatDotLake.Relocationofthehighwayandintroductionof135milesofnewtransmissionline,a210foothighand6,400footlongdamandexistenceofotherfacilitieswouldreducetheattractivenessoftheareaforrecreationandsightseeing,especiallyfromtrailsrecommendedbytheStateforprotectionmentionedpreviuosly.Thenewreservoirwouldhaveonlyverylimitedrecreationvalueasaresultofextensivemudflatsandshoreerosio~duringdrawdown.SightseeingandperceptualimpactstorecreationistscouldoccurinthevicinityofLakeGeorgeduetothepresenceofasaddl~damlessthanamilefromitsshores.Competitionforresourcesandfacilitiesthroughincreaseduseofthearearesultingfromnewaccessandmorepeoplemayalsooccur.Recreationdemandwouldlikelyincreasesubstan~iallyduetothepredicteddoublingoftheresidentpopulation.This,~nturn,wouldresult~nincr.easeduseofexistingregionalandcommunityrecreationfacilities.AestheticsThedominantlandformintheJohnsonprojectarea~stheAlaskaMountainRange.TheJohnsonRiverislocatedinaglaciatedU-shapedvalley.It~sabraidedriverthatflowstowardthebroadvalleyoftheTananaRiver,whichisborderedbytheAlaskaRangetothesouthandrounded,gentleridgesandslopesoftheYukon-Tananauplandareatothenorth.Thevegetationnearthedamsite~spredominantlybottomlandspruce-poplarforest.Vegetationathigherelevationsisml":>stlyuplandspruce-hardwoodforest.ThissectionofthevalleyisconsideredbyADNRtohavemoderatescen~cvalueandthehighwayhasbeenrecommendedforscenicprotectionbyADNR453410/78408207-6 '1~I(1983)intheTananaBasinPlan.Guidelinesforthisclassificationallowlimiteddevelopmentaslongasitdoesnotdegradeordetractfromthescenicqualityandviewsofthearea.MajorviewstothenorthareorientedtotheWrangellMountainsandtheKnobRidgeareatothesouth.Foreground'viewsconcentrateontheriverlowlandsandassociatedwildlife.NotablenaturalfeaturesaretheTowerBluffRapidsandthebluffsthemselvesatthesoutheastendoftheinundationzone.Extendedviewsofvar~oustributaryvalleyssuchastheRobertson,Johnson,Billy,andSandvalleysarealsopossible.Impactswillprimarilyresultfromthefloodingof94,500acresofvalleylandandwildlifehabitat.Furtherimpactswi.llresultfromtherelocationofasectionoftheAlaskaHighwayandanexistingabovegradepipelineontosteeperlandduetothesignificantamountofconstructionactivityandcutsintothemountainousterrain.SincetheAlaskaHighwayisamajortravelrouteinAlaska,thevisualimpactsofthereservo~randotherprojectfacilitieswouldbe.visibletoalargenumberofpeopleandthereforearequitesignificant.Foregroundviewswillbedominatedbythereservoirwithitsassociatedmudflats,whichwillbeextensive.Valleyvistaswillbeflooded,.aswillTowerBluffRapids.Viewsupanddownthevalleywillbefurtherdegradedbytheintroductionof135milesofnew,project-relatedtransmissionlines.Newright-of-waywillberequiredfor45ofthe135milesoftransmissionline.Viewsofthe.210foothighby6,400footlongdamandassociatedfacilitieswouldbepossibleforsomedistancedownthevalley.7.2.1.2TerrestrialResourcesTheJohnsonprojectwouldcreateareservo~rinundatingapproximately94,500acresofwildlifehabitat.Inaddition,vegetationandanimalswouldbedisturbedduetotheconstructionofthetransmissionlinesandrelocationoftheexistinghighway.Theimpactedareaismainlybottomlandspruce-poplarforestwiththeTananaRiverfloodplainsupportingriparianvegetation.Thebroadfloodplainisdissectedbysidechannelsandsloughs,j453410/78408207-7 ,J]]1,]1~Jcreatingamosaicofembankmentsandislandsvegetatedwithshrubsandpoplar.InthefoothillstothenorthandsouthoftheTananaRiver,andalongtheJohnsonRiver,thevegetationismostlyspruce-hardwoodforest.IntheSandCreekandBillyCreekdrainagesandinportionsoftheTananabottomlands,themainstemchannelandsidesloughshavecreatedwideareasofwetlands(wetmeadows,bogs,andponds)andlowlandscoveredwithsedge-grassandlowshrubcommunities.Basedonestimatesmadefromu.S.GeologicalSurveytopographicmaps,approximately30,000acresoflowlandwetlandsarepresentinthearea.Athigherelevations,thespruce-coveredmountainslopesgivewaytolowshrubandalpinetundracommunities.TheimpoundmentzonefromJohnsonSloughtoBillyCreek,andtheBillyCreekdrainageareimportantmoosewinterrangebecauseit1Salowelevationareaandcontainsearlysuccessionalvegetationimportantasmooseforage,withinactivefloodplains.TheBillyCreekdrainageisanimportantcalvingareaandsummerrange.Inthefall,moosemoveintothenearbysubalpinedrawstomate.SubalpinewillowstandsprovidefooduntilheavysnowsforcetheanimalsdowntocriticalwindblownareasalongtheTananaRiverfloodplain(ADNR1984b;Martin1983).TheTananaRiverlowlandsandtheSandandBillyCreekdrainagesprobablyrepresentcriticalwinterrangeforlocalmoosepopulationsduringseverewinters.Averageyear-roundmoosedensitiesintheareahavebeenestimatedtobe1moose/mi2(Johnson1984).TheMacombcaribouherdfrequentstheMacombPlateau,twotothreemilessouthoftheproposedimpoundmentinthevicinityofDryCreek.Th~animalsgenerallydonotoccurintheimpoundmentzone.However,duringseverewintersofdeepsnow,someanimalswillutilizetheTananaRiverdrainage,•especiallytheJohnsonSlough-SandCreekflatsarea(Martin1983;ADNR1984b;Johnson1984).Dallsheepdonotfrequenttheimpoundmentzone,butarefoundinthemountainousareasattheheadoftheJohnsonRiver,DryCreek,SheepCreek,andCathedralCreekdrainages(Martin1983).453410/78408207-8 ]Cl]'1J]]]J.JBrownbearsoccasionallyvisittheBillyCreekdrainageduringmoosecalvingperiods,butmainlyfrequentalpineridgesandareasabovetheimpoundmentzone.Blackbearsfrequenttheentireimpoundmentzone.Special-useareasincludelowlandsandvalleybottomsalongthesouthbankoftheTananaRiver,BillyCreek,andsmallerdrainages,inadditiontosubalpineandalpineberrystands(ADNR1984b;Johnson1984).LowlandsassociatedwiththeTananaRiver,JohnsonSlough,andBillyCreek,arespecial-useareasformink,'muskrat,otter,andbeaver.Redfoxutilizetheriparianvegetationandsedgehummockareas.RiparianareasalongGeorge,Sand,andBillycreeksareimportanthuntingandtravellingcorridorsformanyfurbearersincludinglynx,coyote,wolf,andwolverine(ADNR1984b).TheDotLake,SamCreek,andBillyCreekwetlandscompriseimportantwaterfowlhabitat.Basedonestimatesmadefromu.S.Geologic.alSurveytopographicmaps,approximately30,000acresoflowlandwetlandsarepresentinthearea.Theseregionsprovidenestingandmoltinghabitat,andstopoverareasduringmigrationforhighconcentrationsofseveralspeciesofwaterfowlandsandhillcranes.Goldeneagles,baldeagles,andred-tailedhawksnestintheimpoundmentzone(ADNR1984b,Robus1984).Inaddition,fourperegrinefalcon·nestlocations(threeofwhichwereactivein1983)occuralongtheshorelineof.theimpoundmentzone(Robus1984;Money1984).Thisspecies~sclassifiedas"endangered"bytheU.S.Dept.ofInterior,FishandWildlifeService.Sprucegrouse,ruffedgrouse,andwillowptarmiganarepresentandhuntedintheimpoundmentarea(Martin1983)•TheamountofhabitatlostordisturbedduetotheJohnsonprojectwouldbeapproximately98,160acres(Table2).Theprojectwouldeliminateyear-roundhabitatimportanttolocalmoosepopulationsespeciallyaswinteringandcalvingareas.Becausemuchofthisareaprobablyrepresentscriticalwinterrangeduringseverewinters,loss·ofthiswinterrangeislikelytoresultinasignificantreductioninareamoosepopulations.Tnelossof1J453410/78408207-9 ClJl]]]"lj1J1I. JJlowlands,andtheriparianvegetationassociatedwiththoseareas,wouldeliminateimportantspecialuseareasandyear-roundhabitatforblackbearsandremovevaluablehabitatformostfurbearers.Theimpoundmentwouldeliminateprimewaterfowlnesting,molting,andstopoverhabitat,andwouldinundatemanyraptornestinglocations.Fourperegrinefalconnestlocationswouldbesignificantlyimpactedresultingintheprobableabandonmentofoneormoreoftheselocations.7.2.1.3AquaticResourcesTheAlaskaDepartmentofFishandGame(ADF&G1983)hasdocumentedthatchum,coho,andchinooksalmonmigrate.upstreamoftheJohnsondamsite.Chumsalmonhavebeenrecordedasfarupr~verasthemiddleChisanaRiver,orapproximately1,297rivermilesfromthemouthoftheYukonRiver.Chumsalmonspawninghasbeenrecordedwithintheproposedimpoundmentzone,primarilyinsloughareasoftheTananaRivernearitsconfluencewithBillyCreek(Exhibit3).Majorchumspawningareashavebeendesignateddownstream,particularlyneartheconfluencewiththeDeltaRiverwhich~sapproximately55to65milesdownstreamofthedamsite(Buklis1981).Althoughquantitativeestimatesofescapementtoareasupstreamofthedamsitearenotavailable,itisexpectedthatthesefishcontributetotheextensivecommercialandsubsistencefisheriesthatoccurinthelowerTananaRiverandinthe.lowerYukonRiver.Forexample,frominformationdevelopedbyADF&G(1983),.approximately144,000chinook,13,000coho,andover1,000,000chumsalmonwerecaughtinthecommercialfisheriesdownstreamoftheproject.inthelowerTananaandYukonr~vers(includesDistricts1,2,3,4a-c,and6;portionsofDistrict5areabovetheconfluenceandthereforetheentireDistrictwasexcludedfromthisestimate).AlaskaDepartmentofFishandGamefigureson1984subsistencefishingshowthatduring1983,475chinook,2,276summ~rchumsand3,830fallchumandcoho(combined)weretakenintheTananaRiverupstreamofWoodRiver(Exhibit1).(Thesesubsistencenumberswerederivedfrom147permiteesreportingcatches,outofatotalof259permitsissued).453410/78408207-10 1Cl:]]]\JJ1JInordertomaintainthosefishwhichspawnupstreamoftheproposedJohnsondamsite,itwouldbenecessarytoincorporatestructuresthatfacilitatebothupstreamanddownstreampassageofanadromousfish.Withthelargesizeofthereservoir,itisuncertainifsuchpassagefacilitieswouldbeofvaluebecausethefishmaynotbecapableofpassingthroughthereservoirduetoitslargesizeanditschangefromaflowingwatersystemtoalake-likereservoir.Itisalsouncertainwnetherornotthepassagefacilitieswouldbesuccessfulinmovingfishupstreamanddownstreamofthedam.Chumsalmonresourcesupstreamofthesitewouldbeparticularlysensitiveandprobablywouldbeeliminated(Bell1984).Similarly,successwithadaptingcohoandchinooksalmonthatarenormallyaccustomedtoriverinehabitattonewlycreatedlargeimpoundmentshasnotbeendemonstrated.Therefore,onaworstcasebasis,thesespeciesmightalsobeeliminated.Mitiga'tionmightberequiredforspawningareaslostwithinthe.impoundmentzoneandforareaspotentiallyimpacteddownstreamoftheproject.Suc~measurescouldincludeflowregulation,habitatmodification,orartificialpropagation.Additionalimpactsdownstreamthatwouldpotentiallyrequiremitigationarechanges1.nturbidity,temperture,fishspawningandrearinghabitat,fishgrowth,andwaterquality.ResidentfishwithintheproposedimpoundmentzoneincludeDollyVarden,burbot,grayling,whitefish,sheefishandnorthernpike.Noestimatesareavailableonthenumbersoffishpresent.However,accordingtoADF&G(1983),"fisharereportedtobesecondtomooseincomprisingalargeamountofwildfoodinDotLakeresidentsIdiets."Manyof.thesefisharecaughtfromareaswithintheproposedimpoundmentzone,primarilybysetgillnet.Themaintypesoffishofinterestarefoursep~ratespeciesofwhitefish.Additionalfisnaretakenfromsmalllakesandstreamsintheimpoundmentzonebyrodandreel(Martin1983).Extensivestudieswouldberequiredtoquantifypotentialimpactsandformulatedetailedmitigation·plans.\,J453410/78408207-11 -1-)]]1J7.2.2BrowneSite7.2.2.1SocialSciencesSocioeconomicsTheplacesthatwouldlikelyexperiencesocioeconomicimpactsfromdevelopmentoftheBrownesiteandassociatedfacilitiesareHealyandNenana.HealyandNenanacurrently.havepopulationsofabout350and475persons,respectively(U.S.BureauofCensus1980).PopulationinfluxestoNenana(whichisapproximatelyone-halfNativeAlaskan)duringthepeakconstructionphaseoftheBrowneprojectcouldcreatethemostsevereimpacts.CulturaldifferencesbetweenNativeresidentsandnon-Nativeinmigrants,interferencewithsubsistanceactivities,anddramaticchangesinlifestyles(suchas,notknowingone'sneighbors,moreformalpersonalandbusinessrelationshipsandshifts~nlocalpowerstructure)forcurrentresidentsaccustomedtoasmall-townsettingwouldoccur.Economicopportunitiesmightexpand,butthesewouldbeofmorebenefittodevelopersandin-migratingsupportworkersandtheirhouseholdsthantocurrentresidentswhowouldbelesslikelytohavetheexperiencenecessarytoadequatelyprovideneededservicesandskills.InNenanaaswellasHealy,shortfallsinhousingandcommunityandcommercialserviceswouldlikelyoccur,andtheplanningandfinancingproblemsforrapidgrowthwoulddevelop.Fairbankswouldnotbeexpectedtoexperiencesuchgreat.difficulties.Fromaerialreconnaisance,itappearsthat5to15housesmaybeinundatedbytheBrowneimpoundmentinanareajustwestoftheriverneartheupperriverlimitsoftheimpoundmentzone.Inaddition,onerecentlybuilthouse,barn,andgaragenearJuneCreekwouldbeinundated.Peopleinallofthesehousesmayhavetoberelocated.Eveniftheyareabovetheinundationzone,theprojectwouldstillextensivelychangetheseresidentssurroundingsbyreducingthelandandterrestrialwildliferesoursebase;453410/78408207-12 )"]-1"]]\jcreatinglakeshoreproperty;andpresentingnewpotentialforcommercial,residential,recreational,and'naturalresourcedevelopment.LandUseThepredominantexistinglandusesattheBrowneprojectsitearerecreation,settlementandagricultureswhichislimitedbypoortomoderatesoilconditions.Theseusesareoflowintensity.Themajorityoftheselandshavebeen,orarebeingdisposedtoprivateindividualsbytheStateasremoteparcelsorsubdivisionlands.Consequently,ownershipisforthemostpartprivateorState,withtheclosestNativeparcelslocatedtothesouthwestapproximatelyonemilefromtheinundationarea.Project-relate~impactswouldbesevereasthereservo~rwouldinundate12,500acresofagriculturalsubdivisionandremoteparcellandsdesignatedfordisposaltoprivateindividualsbytheState.AtleastoneminingclaimandportionsoftheGeorgeParksHighwayandtheAlaskaRailroadwouldbeinundated.Thesubdivision,knownastheHealyAgriculturalSubdivision,hasmixedareasofpermafrostandagriculturalsoils.Additionallandsrequiredforaccessandtransmissionrouteswouldcrossapproximately20to30milesofprivatedisposedorStatelands,therebypotentiallyincreasingdevelopmentpressure,increasingcompetitionforrecreationopportunitiesanddisruptionofthenatural,remotesetting.Sincetheinundationareais·intendedforprivateownership,projectusescouldconflictwiththoseofavarietyofprivatelandowners.CulturalResourcesTheBrownesite~spresentlyknowntocontainmorethan50archeological~ndhistoricsites,manyofwhicharebelievedtobe.significant(FERC1984;Appx.0).Atleasttwositesarelocatedatthedamsiteandwouldbedirectlyimpacted.Theexactnatureandextentofculturalresourcesurveysintheareaisunknown,andanadditionalsurveywouldberequiredtofully453410/78408207-13 ]]-1.~J]]]:J]Jidentifyunrecordedsites.ImpactsandnecessarymitigativemeasuresmaybequalitativelysimilartothoserequiredfortheSusitnaproject.RecreationTheBrownesiteislocatednorthofHealyonthemiddlesectionoftheNenanaRiver(Exhibit2).Theproposeddamsiteisapproximately12milesfromtheDenaliNationalParkandPreserve.ThereservoirwouldbeapproximatelytwomilesfromtheParkBoundary.TheGeorgeParksHighwayandtheAlaskaRailroadparallelther~ver.Bothtransportationcorridorsareheavilyusedforsightseeing.InadditiontheNenanariverisusedintensivelybylocalresidentsforr~vertravelandmoderatelyforrecreationalboatingandfishing.Otherareaactivitiesincludeamoderatelevelofhunting,fishing,andhiking(ADNR1982).Guidelinesforthisclassificationallowonlylimiteddevelopmentcompatiblewithrecreationopportunities.DevelopedrecreationfacilitiesintheareaincludetheDenaliNationalParkandPreserve,privatelodges,highwayrestareas,andscenicoverlooks.Withintheprojectarea,thereareanumberofsmallareaswhichtheADNRconsiderstohavehighrecreationpotentialandwhichtheyhaverecommendedforstateprotection(ADNR1983).TheseincludeJuneandBearcreeksandKobeHillareas.PotentialrecreationimpactsoftheBrowneprojectinclude:severeimpactstoasightseeingcorridorofhighscen~cvalue(byintroducingprojectfacilitiesincludingareservoirwithdrawdownandshoreerosion);impactstorecreationistsinDenaliNationalParkwhowillviewthedevelopment;andlossofr~verboating,hunting,fishing,andhikingopportunities.Impactswillalsoresultfromtherelocationofthehighway,railroad,andexistingGoldenValleyElectricAssociation(GVEA)transmissionline.Inaddition,theADNRrecreationsitesatJuneandBearcreeksaswellastheJuneCreekrestareawillbeinundated.Moreover,KobeHillwillbe1J453410/78408207-14 r]]-JJseverelydegradedbyconstructionoftheleftdamabutmentandotherprojectfacilitiesonitsflanks.Thereservo~ritselfwouldhavelimitedvalueasarecreationresourceasaresultofdrawdownsandassociatedmudflats~nthesummer.Windyconditionsonthereservoir,lackofcurrent,andturbidwaterswillalsodetractfromthevalueofthereservoirasarecreationalattraction.IceslumRinginthewintermaycreatehazardoussituationstopotentialusersaccessingareasviathereservo~r.AestheticsThissiteishighlyvisibleduetoitslocationwithinv~ewofDenaliNationalPark,theGeorgeParksHighway,andAlaskaRailroad,whichareallheavilyusedforsightseeing.TheParksHighwayhasbeenrecommendedforscenichighwaydesignation(ADNR1981).Furthermore,thissegmentLSconsideredtohaveveryhighscenicvalueastherearegoodopportunitiesforviewstotheAlaskaMountainRange.Inparticular,Kobe!lilloffersvistasupanddownthevalleyandintoDenaliNationalParkandPreserve.AestheticimpactsoftheBrownealternativewouldbequitesignificant.Impactstotheareawouldincludeeliminationoflongvalleyviewsduetoconstructionofthe265foothighdam,constructionof25milesofnewtransmissionlinesandotherprojectfacilitiesintothehighlyscenicandvisibleNenanaRiverValleywhichhaslittlecapabilitytoabsorbvisualimpacts.ViewsfromKobeHillwillbeseverelydegradedbytheconstructionofthedamandpowerhouseonitssideslopes.Themajorimpact,however,willresultfromtheinundat{onofthevalleyfloor,whichwillnecessitaterelocatingthehighway,railroad,andanexistingpowerline.Locatingnewalignmentswillbedifficultasallflatlandwillbefloodedandconstructionwillcauseextensivescarring.Inaddition,viewsintothemountainsmaybelostandforegroundviewswillbedegradedby·constructionscarring,beacherosion,muddyreservo~rwaters,andextensivemudflats.TheseimpactswouldbevisibletomanyviewerssinceJ453410/78408207-15. ]C]]]1JtheGeorgeParksHighwayandtheAlaskaRailroadaremajortravelandtouristroutes.ViewsofprojectfacilitiesfromthenorthernbordersofDenaliNationalParkwouldalsobepossible.7.2.2.2TerrestrialResourcesVegetationalongtheNenanaRiverwithintheBrowneimpoundmentarea~svaried.Theriverislandsandstreambankssupportashrub-poplarplantcommunitywithoccasionalaspenstandsonthesloughbanks.Thebroadfloodplainareaextendingfromtheriverchanneltothebaseofsurroundingfoothillsiscoveredwithripariancommunities,occasiona1lyintermingledwithlowspruceandpoplar.Noticeableinthisregionareopenareasofwetmeadowsandthinlytimberedblacksprucewoodlands.Athigherelevationthevegetationgradesintolowshrubandalpinetundracommunities.Approximately12,500acresofhabitatwouldbeinundatedbythisproject,andanadditional4.5milesofdisturbanceduetotransmissionlineconstructionwouldoccur.Rebuildingandreroutingabout8.Smilesofhighwayand16milesofrailroadtrackinundatedbythisprojectwouldcauseadditionallongandshort-termimpactsonvegetationandwildlifebothinsideandoutsidetheimpoundmentzone.ThemoosepopulationinthevicinityoftheBrowneprojectareahasbeendescribedasgoodandexpanding(Jennings1984).Averageyear-roundmoosedensitiesintheareahavebeenestimatedtobe1-1.5moose/mi2<Jennings1984).ManyanimalsutilizethewillowanddwarfbirchsubalpineandalpinecommunitieseastoftheNenanaRiverafterthematingperiod.Wheretheses\1rubcommunitiesarewindblownandfreeofdeepsnow,highdensitiesofmoosewillrema~nthrougnoutthewinter.Whensnowbecomestoodeep,moosewillmoveintothelowlandvalleysandriverfloodplainstoutilizetheripariancommunitiesthatoccurintheseareas.Intheimpoundmentzone,thebroadriverfloodplainsbetweenBrowneandFerryfunctionmainlyaswinterrangeinadditiontoprovidingcoverduringthecalvingperiod(ADNR1984b).453410/78408207-16 J11J]]']])JJ1~JCaribouinthereg~onbelongtotheDeltaherdandmainlyoccur~nthefoothillseastoftheNenanaRiver.MatinggenerallytakesplacebetweentheNenanaandWoodriversinthemountainsandtundracoveredorbrushyplateaus.Theearlypartofthewinterisusuallyspentinthesamearea,butsomecariboucrosstheNenanaRiverandwinterintheOttoLake-Healyregionapproximately25milessouthoftheproposeddamsite.Smallnumbersofthiswinteringgroupofcaribouoccasionallywandernorthandusetheimpoundm~ntareaasawinterrange(ADNR1984b).Bothblackbearandbrownbearoccur~ntheareabutbrownbeartendtobemorenumerous(Jennings1984).BrownbearforagethroughouttheBrowne.impoundmentarea,concentratinginthevalleybottomsinearlyspringwheregreenshootsfirstappear.Therestoftheyearisspentinthesubalpineandloweralpineshrubcommunitieseastandwestoftheproposeddamsite.ComparedtootherareasintheTananaBasin,presentblackbearpopulationsintheimpoundmentareaarelow(populationsareconsideredtobemoderatenorthofClear).Theblackbearsthatdooccurintheimpoundmentareamainlyutilizethelowlandandfloodplainriparianareas.BothbearspecieshavebeenpostulatedtomoveoutoftheimpoundmentzoneinspringinordertotraveltosalmonspawningstreamsinthetributariesoftheNenanaRiver,travelingasmuchas50milestoreachthem(ADNR1984b).TheBrowneimpoundmentareaprovideshabitatforthefullrangeofInteriorAlaskafurbearers.Residentinthefloodplainandlesstimberedshorelinesarecoyote,redfox,weasels,muskrat,wolves,andbeaver.Intheforestedareas,marten,wolverine,andlynxoccur.Becauseofeasyaccessviathehighway,railroad,andtrails,thisportionoftheNenanaRiverdrainageisintensivelyusedbylocalfurtrappers(Robus1984).TheNenanaRiverisamigratorycorridorforwaterfowlnesting~nnorthernAlaska(AEIDC1974).Thepaucityoflakescapableofproducingwaterfowlfoodintheimpoundmentarearesults~nlittlewaterfowlnesting.453410/78408207-17 ]]1J1~JThemainuseofthesloughsandpondsintheareaappearstobeasrestinghabitatformigratingducksandcranes.Raptoruseoftheimpoundmentareaisunknown,butinsimilarhabitatfurthersouth(nearHealy)nestsitesforred-tailedhawks,sharp-shinnedhawks,kestrels,andgoshawks.havebeenfound(Elliott1984).Baldeaglenestingalongtherivermayalsooccur.TheamountofhabitatlostordisturbedduetotheproposedBrownehydroproject,includingtheinundationzoneandmajorprojectfacilities,wouldbeapproximately13,090acre-s(Table2).Theprojectwouldremove.year-roundhabitatformooseespeciallyimportantduringwinterandcalvingseasons,inanareawheremoosenumbersareincreasing.Inundationoftheareawouldeliminateearlyspringgreen-upvegetationusedbylocalbrownbears,year-roundblackbearhabitat,furbearerhabitat,andraptornestinglocations.7.2.2.3AquaticResourcesTheADF&G(1983)hasdocumentedtheoccurenceofchinook,chumandcohosalmonupstreamoftheBrownesite-asfarasthetownofLignite(approximately18milesupstreamofthedamsite).Althoughnoquantitativeestimatesareavailable,thesefishcontributetoimportantdownrl.versubsistenceandcommercialfisheriesinthelowerTananaandthelowerYukon,muchthesameasthosefishpotentiallyimpactedbytheJohnsonsite(seeSection7.2.1.3).Itisanticipatedthat,duetotheexistenceofanadromousrunsupstreamofthedam,fishpassagefacilitiesliouldbeneededfor,theBrownesitetofacilitatebothupstreamanddownstreampassage.Thesuccessofsuchfacilitiesisuncertainexceptthatchumsalmonpassageprobablywouldnotbesuccessful(Bell1984).Onaworst-casebasis,allotherrunsofanadromousspecieswouldalsobeeliminatedfromupstreamareas.Downstreamofthesite,spawningareasoccuroverawidearea,particularlyinthecomplexofsloughs,riversandcreeksinthelower10milesofthe453410/78408207-18 '1,.1J]1JNenanaRiver(ADF&G1983).Impactscouldincludeeffectsofchangesintemperatures,turbidity,fishspawningandrearinghabitat,fishgrowth,andwaterquality.Mitigationfortheseimpactscouldincludeinstreamflowregulation,habitatmodificationorartificialpropagation.Developmentofsuchplanswouldrequireextensiveconsultationwithresourceagenciestodeterminewhichmitigationmeasureswouldbeneeded.Residentspeciessuchasgr?yling,burbot,sheefishandwhitefish,thatarecommontotheTananaRiverdrainagewouldmostlikelybefoundatthissite./Creeksandlakesinthevicinityoftheproposedprojectareknowntosupportsportfisheries,particularlyforgrayling.However,noinformationisavailableonthelevelofharvest(ADF&G1983).7.2.3KeetnaSite7.2.3.1SocialSciencesSocioeconomicsThecommunitieswhichwouldexperiencethemostsignificantsocioeconomicimpactsfromdevelopmentoftheKeetnasiteincludeTalkeetna,andTrapperCreek(Exhibit4).The1981populationofTalkeetnawasestimatedat640;TrapperCreekwasestimatedat225(FERC1984).TheimpactsinTalkeetnaandTrapperCreekwouldbeofatypesimilarto,butoflessermagnitudeandforashorterperiod,thanthoseprojectedfortheSusitnaproject.Projectionsofpeakconstructionperiodpopulationsshowthat,fortheKeetnaproject,Ti:ilkeetnawouldexperienceabouta45percentincreaseinpopulationandTrapperCreekabouta20percentincrease.Iftheaccessroadandtransmissionlineconstructionworkforcearealsoconsidered,thesepercentageswouldbegreater.Rapidgrowthwouldoccurandthesmall-townrurallifestylesofresidents(intheseandotherRailbeltcommunities)wouldbeaffected.Additionally,bothTalkeetnaandTrapperCreekwouldbelikelytoexperiencesubstantialincreasesinhousing453410/7840820.7-19 c1needs.Thesecommunitieswouldalsobeexpectedtoinstallcentralizedwaterandsewerandexpandschools,policeandfire,andhealthfacilities.LandUseCurrentlandusesattheKeetnadamandinundationsitesare~haracterizedbydispersedlow-intensityrecreation,huntingandfishingactivitiesonStateland.ImmediatelytothewestaresettlementlandsdisposedofbytheStatetoprivateindividualsashomesteads,subdivisionsandremoteparcels.Thus,theStateandprivateindividualsownthelandinandaroundtheprojectarea.Fewimmediateorlocalizedeffectswouldresultfromthecreationofadamand5,500-acreimpoundmentinthisareasincethelandisState-ownedanduseislimited.However,thedevelopmentofaccessandtransportationroutescouldposeconsiderableproblemssincetheywouldcrosstheprivatelandstothewest.Thenegotiationofpurchasesoreasementswouldbenecessaryandpossiblydifficulttoobtain.Resultantimpactstothearea,whichmightcreateconflictswithprivateusesoftheland,wouldincludeincreasedtraffic,increasedrecreationpressuresonStatelandsaroundthesite,andeffectsonremoteandnatural·settings.CulturalResourcesNoculturalresourcesitesarepresentlyknowntoexistwithintheKeetnaprojectarea(FERC1984;Appx.0)becausenosystematicsurveyshavebeenconducted.Archeologicalsurveysarenecessaryto~nsurethefullidentificationofeachsitepresentinthearea.Therelativelysmalls~zeoftheKeetnaimpoundmentsuggeststhatfewersitesmightbeaffectedbyinundationthanmaybeaffectedbythelargerSusitna,Browne,andJohnsonalterna.tives.J453410/713408207-20 'j,J'J)JRecreationTheprojectwillflood12milesofthemiddlesectionoftheTalkeetnaRiver.Theupperwhite-waterportionsoftheriverareconsideredsomeofthefinestraftingandwhitewaterareasinAlaska.AccessfromTalkeetnav~apowerboatsispossibleasfarupstreamasapproximatelytwomilesabovetheconfluencewithIronCreek(Exhibit5).Thelowerportionoftheriverisverypopularforcanoeing,sp'ortfishing,andotherwater-relatedactivities.DisappointmentCreek,whichislocatedjustupstreamofthedamsiteandwouldalsobeinundated,isapopularfishingcreek.Landareasadjacenttotherivercorridorareconsideredtobeexceptionallyvaluableforwildlife,andmanytypes.ofwildernessrecreation.TheTalkeetnaRiverhasbeenrecommendedasaStaterecreationriver.TheSusitnaAreaPlan(ADNR1984c)callsfora0.5milewidecorridorontheTalkeetnaRiverand1,000footwidecorridoronDisappointmentCreek.Thesecorridorsarerecommendedforprotectingfish,riparian,andwildlifehabitatsandprovidingavisualbufferforrecreation.Onlylimiteddevelopmentthatiscompatiblewiththerecreationalcharacteroftheareawouldbeallowed.TheKeetnaprojectwouldhavesignificantimpactstoboating,fiShing,andhuntingactivities.TheTalkeetnaRiverispresentlybeforetheAlaskaStateLegislatureforapprovalasaStaterecreationriver.Accessandconstruction-relatedactivitieswouldhaveasignificanteffectonthecommunityofTalkeetnawhichwouldmostlikelynecessitatetheneedforadditionalrecreationalfacilitiesforthatcommunity.Accesstothedamsitewouldalsosignificantlyincreaseuseofthesurroundingareaforhunting,fishing,andotherdispersedactivites.RecreationimpactsresultingfromdammingtheTalkeetnaRiverwouldincludethe'lossofoneofAlaskaIs~ostimportantwhite-waterkayakingandboatingresources,blockageofupstreampassageforriverboats,inundationof12453410/78408207-21 :1'j:Jmilesoftheriver,andpotentialeliminationofpopularfishingresourcesandsitesupstreamofthedam.Landrelatedimpactswouldincludeinundationsof5,500acresofriparianandotherwildhabitatswhichsupportintensivehunting,hiking,andotheractivities.ThearealostwouldincludesomeofthemostpopularmoosehuntingareasintheSusitnaBasin(ADNR1984c).AestheticsTheKeetnasiteislocatedinthelowerhalfoftheTalkeetnaRiverBasin.ThemajorlandformistheTalkeetnaMountains,locatedtothenortheast.Theveg.etationabovethe'riverathigherelevationsisamixtureoflowshrubcommunities,sedge-grasstundra,andmatandcushiontundra.TwoscenicareaslocatedinthevicinityincludeSentinelRockandGraniteGorge(ExhibitE,Vol.9,Chap.10,p.E-10-13oftheLicenseApplication).Aestheticimpactsresultingfromtheprojectincludelossofabout16milesofsceniccorridorwhichisrecommendedforprotectionontheTalkeetnaRiverandDisappointmentCreek,andinundationof5,500acresofriparianandotherwildhabitatswithinarivercorridorpresentlyviewedbyboatersand~ecreationists.Mudflats,whilenotasextensiveassomeoftheotheralternativesites,willstillbevisibletopeopleinthearea.Impactsalsoariseduetotheintroductionofa415foothighdamandassociatedroadsandtransmissionlinesintothescenicTalkeetnacorridor.7.2.3.2TerrestrialResourcesTheKeetnaimpoundmentwouldpermanentlyinundateabout5,500acresofhabitat.Additionalhabitatwouldbedisturbed1ntheconstructionof26milesoftransmissionlineandabout25milesofproje.Gt,accessroads.Spruce-birchforesttypespredominatewithintheimpoundmentzone.Alowshrub-poplarcommunityextendsalongtheriverchannelandasanarrowbanduptheDisappointmentCreekdrainage.ThebroadfloodplainwithintheJ453410/78408207-22 1j:J:J:J]IronCreekdrainagesupportsaripariancommunityintermixedwithpoplarstands.ThesteeplyslopinghillsidesextendingupfromtheTalkeetnaRiverarecoveredwithspruce-birchforest.Athigherelevations,thesprucegradesintolowshrubcommunitiesandmesicsedge-grassandmatandcushiontundra.Mooseutilizetheimpoundmentareayear-round.FallandwinterconcentrationsoccuronthefloodplainandpartiallyforestedislandsthatoccurupriverfromtheKeetnadamsite,especiallyintheregionbetweenDisappointmentCreekandIronCreek(Steen1984).Theimpoundmentareaprobablyrepresentscriticalwinterrangetolocalmoosepopulationsduringseverewinters.Caribouoccupythereg10nonayear-roundbasis.Smallresidentherdsarescatteredoverthearea.Amajorgrouping(150to200animals)occursnearWellsMountainonemileeastoftheimpoundment.Near0-5miles)theimpoundmentzoneasmallherdutil{zestheDisappointmentCreekdrainage,concentratingtheiractivitiesintheupperreachesofthestream(Pitcher1984).DallsheepandmountaingoatsarepresentinthevicinityoftheKeetnaimpoundment,butgenerallyabove2500feet(AEIDC1977).Brownbearsarenotverycommonintheimpoundmentarea,beingfoundinsteadinthelesstimberedhighlandstothenorthandsouthoftheTalkeetnaRiver.However,whensalmoncomeupther1vertospawn,brownbearsfrequentthespawningareasinthe'impoundmentzoneespeciallytheDisappointmentCreekdrainage.BlackbearpopulationsintheareahavebeendescribedbyADF&Gbiologistsas"good",occupyingtheripariancoveredfloodplainsandislandseastofDisappointmentCreek,andthelessdenselytimberedstreamdrainagesandfoothiLls(Steen1984).BecausetheKeetnadamwouldhaveanimpactonanadromousfishrunsupstreamofthereservoir(seeSection7.2..3.3.),itwouldalsoimpactbrownbearsthatfrequentthePrairieCreekdrainage,locatednortheastofthe453410/78408207-23 IIJ1JI.Jimpoundment,becausethebearsconcentrateinthisareatofeedonsalmon.ADF&Gbiologistsregardthisareaasseasonallyimportantcriticalhabitatforbrownbearbecauseitattractsbearsfroma2,800squaremile'area(Miller1983).Thisfoodresourcemaybeimportantformaintainingthecurrentlevelsofbrownbearnumbersinthearea.MillerandMcAllister(1982)estimatedthat30-40brownbearsfishedinthePrairieCreekareainthesummerof1980,and50-100utilizedtheresourceinsummerof1984(Schneider1984).HighbearuseofPrairieCreekduringthekingsalmonspawningseasonhascontinuedtooccur(Miller1983).Theriverdrainagewithintheimpoundmentzone~susedheavilybyfurbearers.Theshrubdominatedfloodplainprovideshabitatandtravelcorridorsformink,weasels,andredfox.Thetreecoveredfoothillsandwoodedriverislandsareusedbylynx,wolf,andwolverine(Steen1984).Little~sknownoftheav~ancommunityinthe.area,butbaldeagleshavebeenobservednestin~.intheimpoundmentarea,particularlyatthemouthofDisappointmentCreek(Arneson1984).Becauseoftheavailabilityofpotentialnestsitesalongtheriverandthefoodresourcesavailableinthearea,itispossiblethatseveralbaldeaglenestsoccurintheimpoundmentzone.ThetotalamountofhabitatlostordisturbedduetotheproposedKeetnahydroprojectwouldbeapproximately5,970acres(Table2).Theprojectwouldeliminateyear-roundhabitatformooseandcaribou,especiallyfallandwinterconcentrationareasforlocalmoose.Theimpoundmentwouldinundateseasonallyimportantsalmonstreamsusedbybrownandblackbears,andaffecttheseasonallyimportantcriticalbrownbearfisheryatPrairieCreek.Lossoffloodplainvegetationwouldeliminateriparianareasandhardwoodsimportanttofurbearersandraptors,especiallybaldeagles.Increasedaccessandtheprobableincrea~einhunting,trapping,andotherhumanactivities,inapreviouslyunroadedarea,willimpactlocalwildlife,particularlybiggameandfurbearers.453410/78408207-24 ]]]IJ1J7.2.3.3AquaticResourcesExtremelyimportantrunsofanadromousfisharefoundbothupstreamanddownstreamoftheKeetnasite(ADF&G1983).Chinook,coho,chumandsockeyespawninupstreamareas,particularlyinthePrairieCreekdrainage(seeExhibits1and5).Forchinooksalmon,PrairieCreekhasconsistentlyhadthehighestspawninggroundcounts(datingbackto1972)forthespeciesofanyeastsideSusitnaRivertributary(Bentz1983).Forexample,the.1982escapementcountforchinooksalmoninPrairieCreekwas3,844fishwhereasPortageCreek,thestreamwiththenexthighestcounthad1,111.Notonlydothesefishcontributetodownstreamcommercial,sportandsubsistencefisheries,theyalsoannuallyattractlargenumbersofbrownb~arsthatpreyonthesalmon(Milleri983).Evenwithfishpassagefacilities,thedamandreserV01rasproposedwouldhavemajorimpactsonanadromoussalmonutilizingtheseupriverareas.Onaworstcasebasis,allofthesefishwouldbeeliminated.Withintheimpoundmentzone,spawningareasforchumandchinooksalmonoccurinDisappointmentCreekandpotentiallyinthemainstemTalkeetna(ADF&G1983).Sitedevelopmentwouldeliminatetheseareasfromproduction.Downstreamofthedamarespawningareaswithinthemainstemandtributariesforallfivesalmonspecies.Duetothesignificantanadromousrunsthatexistatthissite,facilitiesforupstream(potentiallyfishladdersortruckingofadults)anddownstream(screeningorbypassingofintakes)passageofanadromousfishwouldberequired.However,duetotheheightofthedamandthelengthoftheimpoundment,thesuccessofthesefacilitiesisnotcertain.Aswithothersitespreviouslydiscussed,passageforchumsalmonwouldbeexpectedtobeunsuccessful(Bell1984).Mitigationwouldpotentiallyberequiredtoreplacethespawninghabitatlostwithintheimpoundmentzone.Impactsthatcouldoccurdownstreamincludeeffectsofchangesintemperature,turbidity,fishspawningandrearinghabitat,fishgrowth,and453410/78408207-25 1waterqualitychanges.Mitigationfortheseimpactscouldbemadethroughtheuseofflowregulation,habitatmodification,orartificialpropagation.Extensivestudieswouldberequiredtoquantifythelevelofpotentialimpactsandformulateadetailedmitigationplan.Littleornoquantitativeinformationisavailableonresidentfishthatmightbeimpacted.Itisknown,however,thatrainbowtrout,graylingandJDollyVardenarepresent(Watsjold'1984).AsportfisheryforresidentspeciesexistsatthemouthofDisap,pointmentCreek.Increasedaccesstotheareacouldresultinsomenegativeimpactsontheresidentsportfisheriesifproperharvestregulationswerenotimplemented.Mitigationmayalsoberequiredforthesefish.Access°tothesefishingareasisprimarilymadeviaboatfromthetownofTalkeetna.Theaccessroadforthisprojectwouldfollowtheriverandthuswouldallowadditionalopportunitiesforaccesstothearea.]7.2.4SnowRiver7.2.4.1SocialSciencesSocioeconomicsTheareasmostlikelytobeaffectedbytheSnowRiverhydroalternativearetheeasternpeninsulaoftheKenaiPeninsulaBoroughandtheCityofSeward.Togethe+,theseareasformtheSewardCensusDivision,.whichhada1982populationof3,500persons,a31%increaseoverthenumberin1970(FERC1984)•Peakconstructionin-migrationfortheSnowprojectwouldaddabout900persons(excludingworkersneededforconstructionofancillaryfacilities)totheareacreatingadverseeffectsonhousing,commercialoperations,communityservicesandtransportation.AlthoughhousingvacancyratesfortheCityofSewardareunavailable,thefactthatupto300newhousingunitswouldberequiredindicatesthathousingwouldhavetobeexpanded.453410/78408207-26 --J']])JSewer,water,andothercommunityserv~cesaswellasschoolstaffwouldrequireadditionalexpansion.LandUseTheSnowsite~slocatedonFederallandwithintheChugachNationalForest,which~smanagedformultipleuse(Exhibit6).Consequently,thedamand3,200acresofinundatedlandwouldnotbeexpectedtoconflictwithgeneralmanagementpoliciesalthoughsite-specificmanagementplansmaynotfavorsuchause.Impactsduetoproject-relatedaccessandthereservoirwouldincreasebackcountryuse,increaseimpactsonvegetationandwildliferesources,andaffectthenaturalsettingoftheforestlands,particularlyinareasneartothehighway.Recentproposeddevelopments(e.g.,accessroadstominingclaimsontheRussianRiverandplacerminedevelopmentonQuartzCreek)inthisgeneralareahavegeneratedconsiderablecontroversyandstrongoppositionfrompublicandenvironmentalgroups.SimilarcontroversywouldprobablyalsobegeneratedfortheSnowproject.CulturalResourcesThegeneralareaoftheSnowRiverprojectpossessesseveralknownhistoricsites(FERC1984).However,nodetailedsurveyshavebeenundertakenoftheprojectarea.ExtensivesurveysarenecessarytoidentifyandevaluateculturalresourcesintheSnowprojectarea.Therelativelysmallsizeoftheproject'simpoundmentareasuggeststhatfewersitesmaybeimpactedthanmaybeaffectedbytheProposedProjectare.;l.,butintheabsenceofdataonregionalsitedensi.tiesandtherelativesignificanceofthosesites,norealisticestimateofthenatureandextentofadverseimpactscanbemade.RecreationRecreationwithintheNorthForkvalleyincludesmoosehunting,otherbiggamehunting,fishing,campingandhiking.Whiletrailaccessislimited,453410/78408207-27 '-1,J]lJ]]lJ1iJ1JJtwoForestServicecabinsarelocatedontheParadiseLakesforfly-inrecreationists.RecreationdemandintheareaisincreasingandtheForestServicemayopenatrailintotnevalleyinthefuture(Wilson1984).SeveralsizableForestServicecampgroundslocatedalongKenaiLakearewithin5milesofthesite.TheSewardHighwayandAlaskaRailroad,bothofwhichareheavilyusedsightseeingroutes,passbythevalley.Ascenicviewpointislocatedoppositethevalleyopeningforviewsintothesitefromthehighway.RecreationimpactsresultingfromtheprojectwouldincludeinundationofhuntingandfishingareasinawildernessvalleyandinundationoftheLowerParadiseLake,andSnowRivergorge.Projectroadswouldprovideincreasedaccesstotheremainingwildernessareaswithresulting~ncreases~nrecreationdemandforarearesources.Aestheticallyunpleasantviewsofthe310foothighdam,powerhouseroads,transmissionlines,andotherprojectfacilitiesaswellas8milesofriverbedwithregulatedflows,(lowerthanexistingflowsinsummerandhigherinwinter)wouldbehighlyvisibletorecreationistsutilizingareasdownstreamofthedamandtosightseersonthehighwayandrailroad..Constructionactivitiesandnoisewillimpactrecreationistsenjoyingthewildernesscharacterofthearea,andconstruction-relatedtrafficontheSewardHighwaywillconflictwithrecreationtravelontheroadwhichisparticularlyheavyduringthesummermonths.Recreationopportunitiesmaybepossibleonthenewreservo~rasitwillbemoreprotectedfromwindthanKenaiLake.However,drawdownsandassociatedmudflatsintheflatterareaswoulddetractfromitsvalue.Thewaterisexpectedtobeturbid~nthesummer,thusdecreasingtheimpoundment'spotentialforuseasafishingarea.453410/78408207-28 "\jJ]]1Ic.Jj1JAestheticsTheSnowRiverispartoftheKenaiPeninsula'smajorriverdrainagesystem.Theregionischaracterizedbyglaciallycarvedvalleys,rugged,snow-cappedmountainridges,andavarietyofvegetationtypes.Thevisualsettingoftheregion.isdominatedbythesteep,snow-cappedpeaksoftheKenaiMountainRange,withsharplydefinedridges,steep-sidedcrests,andboulderoutcrops.Threeprominentpeaksover4,000feetinelevationsurroundthesitelocation.LargeglacialicefieldsarelocatedintheKenaiMountainsnortheastofthesite.Mixedconiferanddeciduousspeciesconstitutemostofthedenselyforestedvalleyareas.Alpinevegetationandsubalpineherbaceousmeadowsdominatetheslopesabovethetreeline.Slopeshigherthan4,000feetinelevationaretypicallybarrenrockandtalussurfaces.TheNorthandSouthforksoftheSnowRivermeetjustbelowtheproposedpowerhousesiteandflownorthintoKenaiLake(Exhibit6).TheSewardHighwayandAlaskaRailroadrunalongthenarrowKenaiLakeandcontinuepastthemouthoftheprojectvalley(NorthFork)andonsouththroughtheSouthForkValley.Notablenaturalfeaturesintheprojectareaincludethegorgeatthedamsite,ParadisePeaktothesouth,andParadiseLakesintheNorthForkValley.ViewsarepossiblealongtheSouthForkValley(bothnorthandsouth)asareviewsuptheNorthForkValleyfromtheGraylingLakepulloutandtrailheadlocatedoppositethedamsite.AestheticimpactsintheNorthForkValleywouldincludetheinundationofmuchofthelowerportionofthevalley,LowerParadiseLake,andtheSnowRiverGorge.ImpactsintheSouthForkValleywouldincludeviewsofeightmilesofriverbedthatwouldhaveregulatedflows;intensivelanddisruptionfromfacilityconstruction;andviewsofthedam,powerhouse,transmissionlines,andassociatedprojectfacilities.Thisvalley,whichisofveryhighscenicvalue,hasmoderateabilitytoabsorbtheseimpacts.Further453410/78408207-29 ]J])~J\J\,jimpactstotheaestheticqualityoftheChugachNationalForestwillresultfromconstructionorupgradeof87milesoftransmissionlines.SightseersalongthehighwayandrailroadwouldnolongerbeabletoseeuptheNorthForkValley,andundisturbedareaswouldbedegradedbyprojectfacilitiesandconstruction.7.2.4.2TerrestrialResourcesTheSnowhydroelectricprojectwouldinundateabout3,200acresofhabitat.Additionalclearingorlossofvegetationwouldoccurduetotheconstructionof87milesoftransmissionlineandapproximately4milesofaccessroad.Alpinetundratyp~scovertheareasabovetree-linewhileforestedareasalongthemountainslopesanduplandsaremainlycoastalwesternhemlock-Sitkaspruce.Upriverfromthedamsite,thesprucedominatedfoothilisareintermixedwithwetlandareas.Thesebroadwetlandsconsistofsmalllakes,ponds,meanderingstreamchannels,andbogsandwetmeadows.edgedwithwillowsandcottonwood.Theseshrubcommunitiesoftenextendbetweenwaterbodiesandcoverwideareas.ThefaunaoftheKenaiPeninsulaisrelativelysimplecomparedtothatofthemainlandbecausephysiographyposesaformidablebarriertoanimalmigration.ThApeninsulaisconnectedtothemainlandonlybyamountainousisthmusabout12milesacross.ManyspecieswhicharewidelydistributedandlocallyabundantinInteriorAlaska~e.g.arcticgroundsquirrels,pikas,caribou,areeitherabsentorhaveseverelyrestrictedrangeonthePeninsula.Anestimated90-130mooseinhabittheSnowRiverValleyandwouldbeimpactedbytheproject(Spraker1984).ThefloodplainareaonemileeastoftheproposeddamsiteandtheParadiseValleyregionsupportextensiveripariancommunitiesespeciallyimportanttomooseinthespringandwinter.Thetendencyfortheregiontoreceivelargeamountsofsnowmakestheriparianvegetationespeciallyimportantasafoodsourceforwintering.'453410/78408207-30 -IJ\.JJ]]J1.J\l\Jmoose.Thedenseconiferousforestinthereg1.onfunctionsasvaluablethermalcoverandprovidesmoresnowfree,lessenergy-demanding,travelcorridorsforoverwinteringmoose.DallsheepandmountaingoatsdonotfrequenttheSnowimpoundmentzone,butoccupythehigherelevationsites,especiallySheepMountain,AndySimonsMountain,andParadisePeak(AEIDC1974).Thesesitesaregenerallyamileormorefromtheimpoundmentzone.Blackandbrownbearsliveinthearea,withblackbearsbeingveryabundantandbrownbearsatamuchlowerdensity(Spraker1984).Intheearlyspring,brownbearsfrequentthelowlandareasadjacenttothepresentr1.vercorridor,andsouth-facingslopesandmeadows.Fortheremainderoftheyeartheyoccupythehighelevationmeadowsandalpinezonesfoundinthesurroundingmountains.Blackbearuseisheaviestalongtheriversnorelineandfloodplainriparianzones,especiallyintheParadiseLakesarea(AEIDC1974).Thereisalargewolfpack(8to10members)inthearea(Spraker1984).Theforestedareasadjacenttotheimpoundmentzoneprovidemartenhabitat.ThefloodplainandshorelineassociatedwiththemainchanneloftheSnowRiver,andthestreamsandlakesprevalent1.ntheupperParadiseValley,allsupportmuskratandbeaver(Nichols1984).Theriparianvegetationinthevalleyandhighelevationmeadowsintheadjacentmountainsprovidedenningandhuntinghabitatandtravelcorridorsforlynx,coyote,weasels,andwolverine.Baldeaglesnestintheshorelineandfloodplaincottonwoodswhilesharp-shinnedhawksutilizethesmallpocketsofhardwoodsthatoccurthroughoutthespruceforest.Waterfowlusethescatteredpondsandlakes(especialtyintheParadiseLakesregion)asnestingandmoltinghabitat.TheamountofhabitatlostordisturbedduetotheSnowhydroprojectwouldbeapproximately4,110acres(Table2).Theprojectwillremoveyear-round453410/78408207-31 \j'lJ'J-J]1IJ]'.~j!_Jmoosehabitat,especiallyriparianareasimportanttomooseinspringandwinter.Lossoftheshrubareasalongtheriverandfloodplainwillremoveareasvaluabletoblackbearsandfurbearers.Thelossoffloodplaincottonwoodsinclearingtheimpou~dmentzonewillremoveraptornestsites.Increasedaccessandtheprobableincreaseinhunting,trapping,andotherhumanactivitiesinapreviouslyunroadedarea,willimpactthewildlifepopulations,especiallymoose,Dallsheep,mountaingoatsandfurbearers.7.2.4.3AquaticResour'cesBothanadromousandresidentspeciesexistwithintheSnowRiverdrainage.GraylingarefoundinUpperParadiseLake.Bothgraylingandrainbowtroutoccur~nLowerParadiseLakeandprobablyoccurintheSnowRiverbothaboveandbelowthedamsite(McHenry1984).ThesefishcontributetoanexistingrecreationalfisheryprimarilyinLowerParadiseLake.Thislakewouldbeinundatedbytheproposedproject(seeExhibit6)'.Thenewimpoundmentwouldprobablybehighlyturbidduetotherunofffromglacierswithinthebasinandtherefore,thisrecreationalfisherywouldprobablybelost.AlthoughbothNichols(1984)andMcHenry(1984)believeth~tavelocitybarrierexistsnearthedamsitewhichpreventsupstreampassage,ADF&Gdocumentsthatsockeyesalmondomigrateupstreamofthepotentialdamsite(ADF&G1983)~Therefore,theinformationpresentedbyADF&Gin1983needstobeverified.Aworst-caseassumptionthatthesockeyedomigratepastthesitemustbeusedforplanningandcomparisonpurposes.Therefore,eitherpassagefacilities'forupstreamanddownstreammigrationwouldhavetobeconsideredinthedesignoftheprojectorotherformsofmitigationmayberequired.Ifnofishpassupstream,mitigativemeasuresforpassagewouldnotbeneeded.BothcohoandsockeyesalmonspawninghasbeendocumentedintheSnowRiverdownstreamofitsconfluencewiththeSouthFork(ADF&G1983).Anestimateoftotalescapementforthesefishhasnotbeenmade.1J453410/78408207-32 ]]]J]Thesefishwouldcontributetothehighlyimportantsportandcommercialfisheriesinareasdownstream(primarilybelowtheoutletofKenaiLake)thataresupportedbytheKenaiRiversystem(Mills1983).Mitigationforanypotentialimpactsdownstreamoftheproject(primarilyinlowerSnowRiver)wouldrequireextensivecoordinationwithresourceagenciestodeterminethemostappropriateformofmitigation.These.impactscouldincludeeffectsofchangesintemperature,turbidity,fishspawningandrearinghabitat,fishgrowth,andwaterquality.Thesetypesofmitigationcouldincludemaintenanceofinstreamflow,habitatmodification,orartificialpropagation.7.2.5ChakachamnaSite7.2.5.1SocialSciencesSocioeconomicsThesocioeconomicenvironmentoftheChakachamnahydrositewouldincludetheNativevillageofTyonek(approximately.30mileseastofthepowerhousesite)andthesurroundingsparselypopulatedarea.Tyonekhad.apopulationof239peoplein1980,onlysevenpersonsmorethanin1970(FERC1984).Mostoftheemploymentinthisareaisseasonalwithopportunid.esinfishing,timber,andpetroleumexplorationaswellasafewservice-relatedjobsinthevillage·(FERC1984).Averagehouseholdincomein1981was$13,441.Thisfigure,whichisconsideredlowincome,wasapproximately30%belowtheStateIs~verageinthat·year(Darbyshire&Assoc.,1981).Inaddition,householdsrelyonNative/publichealthbenefitsandothersourcesofaidandthereisheavyrelianceonsubsistenceactivities.Damconstructioncouldresultintheprojectedip.migrationofasmanyas2,000peopletothisarea,andsubstantialimpactswouldoccurtotheNativeculture,lifestyle,andsubsistenceactivities.Thisestimateofin-migrantsmaybeconsideredlowbecauseitdoesnotincludetheadditional453410/78408207-33 )']JJ]increasesduetoconstructionofancillaryfacilitiessuchastransmissionlinesoraccessroads.Also,sincethevillagehasnovacanthousing(withtheexceptionof24roomsattheShirleyvilleLodge),housingwouldhavetobesignificantlyexpandedevenassumingthataconstructioncampwouldbeprovided.Theprojectedinfluxofin-migrantsfortheChakachamnaprojectwouldstraincommunityservicesbeyondtheircapacities.Sewerandwatersystems,fireandpoliceprotectionpersonnel,andlocalmedicalfacilitiesandpersonnelwouldhavetobeadded.Commercialoperationswouldalsoberequiredtoexpandanddiversify.Tyonekandthesurroundingareaarenowaccessiblebyunpavedroads;butnoroadtoAnchorageisopenyear-roundexceptwhenthefrozenSusitnaRiverallowsforwintercrossings.OnemainairportinTyonekandseveralprivateairstripsprovideforairtransportationan~abargeservesthecoastline.Permitstoconstructnewaccessroadstothedam~itemaybedifficulttoobtainduetotheTyonekNativeCorporation'spolicyofrefusingeasementsandrights-of-wayontheirland(FERC1984).LandUseTheLakeChakachamnaareaaremoteandrugged,andcurrentlanduseisdiverseandoflowintensity.Ofthecurrentuse,recreationaluses(includinghunting,fishing,andbackcountrytravel)aremostprevalentandincreasing.Project-related,accessroadsandatransmissionlinecorridorintothisareawouldfurtherincreaserecreationalutilization.However,sinceproject-relatedaccessroadsandutilitylineswouldpassthroughlandsownedbytheState,theborough,andNativeenti!:ies,significantconflictswiththevariouslandownerscouldlikelyoccur.Overall,theChakachamnaprojectwouldrequirelimitedconversionoflandsfromoneusetoanother,themajorcnangesoccurringwiththeconstructionoftheaccessroadsandtransmissionline.Therefore,effectsatthelakeJ453410/78408207-34 tapsitewouldbeminimal.Inthefuture,increasedaccessibilitywould-]:llaccelerateprobableresourceextraction,processingandtransportationofoil,gas,coal,andtimber,andaffectthequalityoftherecreationsetting.Inaddition,increasedaccesswouldlikelyproduceincreasedrecreationdemand.CulturalResourcesNohistoricorarcheologicalsitesare.currentlyknowntoexistwithintheChakachamnaprojectareaandfieldreconna1ssanceindicatesthattheproposedsitesforthepowerintakeandpowerhouseshavealowpotentialforculturalsites(Bechtel1983).Aculturalresourcessurvey1Snecessary]toidentifyandevaluateculturalresources.Therelativelysmallsizeofthedirectimpactarea(duetotheabsenceofanimpoundment)suggeststhatfewerarcheologicalsitesmaybeimpactedthanatanyoftheotheralternativehydrosites,butthistentativeevaluationmaylikelybesubjecttorevisiononcefieldsurveydatabecomesavailable.Noestimatecanbe]))madeatthistimeastothesignificanceofsit:eswhichmightbeimpactedbydevelopmentoftheChakachamnaproject.RecreationLakeChakachamnaisinaremotewildernesssettinglocatedinMerrillPass.Thepassisamajoraircorridorforfly-inrecreationistsgoingtoLakeClarkNationalParklocatedwestofLakeChakachamna(Exhibit7).Recrea~ionistslandonLakeChakachamnawithfloatplanesandon·thelake'sgravelbarsandr1verdeltaswithwheeledplanesandusethelakeasastagingareaforhunting,fishing,kayaking,andhiking.Nationalparkrangersestimatethatasmanyas75planesmayflythroughtheareaeachdayandasmanyas10to20peoplemightusetheprojectareainaday(Hartell1984)•SomehikersusethelaketoaccessLakeClarkNationalParkj)Jv1aLakeKenibunatothewest.wildernessandhasnogroundaccess.ThisareaofthePark1Sclassified453410/78408207-35 ]]]RecreationontheMcArthurandChakachatnariversincludeareasofintensehuntingandfishingaswellassonieboating.Bothriverscontainsalmon(seeSection7.2.5.3).ItisnotknownifboatersnavigatetheChakachatnaRiverCanyon.TheTradingBayStateGameRefuge,locatedatthemouthsofbothrivers,1.Stheninthmostimportantwaterfowlhuntingareainthestate.Recreationalimpactsofprojectconstructionwouldincludedevelopingaccessintoremotewildernessareas.ThiswilllikelyresultinincreaseduseandrelatedwildernessexperienceimpactstousersoftheadjacentNationalParkwildernessareas.Inadditionchangesinwaterlevelsandassociatedshoreinstabilityinthelakemayaffectitsusefulnessasarecreationalstagingareaandlimittheabilityofwheeledplanestoland.WaterlevelreductionsintheChakachatnaRiverwillreduceopportunitiesforboatingandfishingandwillreduceflowtothe15milesofChakachatnaCanyonwhitewaterby75percent.Flowincreases1.ntheMcArthurRiverwillalsoadverselyaffectfishhabitat,aswillflowchangesinthewetlandsoftheTradingBayGameRefugeforwildlife.Increasesinpopulationduringconstructionandoperationalongwithhabitatalterationandnewaccessresultingfromprojectfacilities,mayreducehuntingopportunitiesandsubstantiallychangethepatternsofrecreation1.nthearea.Additionally,viewsofprojectroads,about130milesoftransmissionlines,andotherprojectfacilitiesinthiswildernessareamaydegradetherecreationalexperienceforusersofthisarea.AestheticsTheprojectareaencompassesthreecategoriesoflandformcharacteristics:steepmountainousterrain,vegetateduplands,andcoastalwetlands.LakeChakachamna,ChakachatnaRiverCanyon,andtheheadwatersoftheMcArthurRiverarelocatedinnarrowglaciatedvalleyssurroundedbysteep,ruggedmountains.Scenicqualityishigh,particularlyonLakeChakachamnaandtheChakac'hatnaRiver.Thelakeallowsalongviewthatincludes453410/78408207-36 ClJhangingglaciersthatdroptolakelevel.Tributariestothelakeformsymmetricaldeltas.TheChakachatnaRiverexitsthelakeintoacanyonsurroundedbysteepmountains.Atthispointtheriveralternatesbetweensingle-channelandbraidedsystems,andhasrelativelycontinuouswhitewater.ThebraidedfloodplainoftheupperMcArthurRiveris0.75ofamilewide,and~sroughly50percentvegetatedwithcontrastingexposedviewshedisrelativelyshort.--j]sandbars.Becauseofthetwistingnatureofthecanyon,thelengthofVegetationonthesteeplowerslopesofthe']]lakeandbothdrainagesconsistsofathickmixtureofconifersanddeciduousbirchandalders,abovewhichlies.abankofshrubthicket,andalpinevegetation.Thisvegetationprovidesacontrasttoboththelakeandriverfloodplains.Uponleavingthemountains,boththeChakachatnaandMcArthurriversenterwell-vegetateduplands.Here,thebroaderrivervalleysfluctuatebetweenbraidedandsinglechannels.Thedensevegetationoftenlimitsviewsfromunusualvisualareasarelocatedwithintheuplandlandform.AnexpanseofdrysandflatsisfoundalongthemiddlereachoftheMcArthurRiver.Thisdune-likeareaprovidesvisualrelief(textureandcolor)fromthedense'Jtheriversandscreensoutthebackdropofmountains.Tworelativelyvegetation,andallowslongervistasofthesurroundingmountains.Aborderoflichen-coveredflatsfurthercontributestotheaestheticsofthisarea.Similar,butsmaller,areasoflichenflatsarelocatedalongtheChakachatnaRiver.Thevegetateduplandsgraduallygivewaytoopenwetlandsalongbothr~vers.Thesecoastalwetlandsextendinlandroughlyfivemilesfro~thecoast.Thelowvegetationofgrassesandsedgesandopenwaterallowslongvistasofthesurroundingmountains,CookInlet,andtheKenaiPeninsulaacrosstheInlet.Theprimaryriverforminthesewetlands~smeanderingsingleJchannelswithsteepmudbanks.upchannelinsomeinstances.TidalinfluenceextendsfourormoremilesThesecoastal.wetlandsprovideexcellentwaterfowlhabitat,-andhaverelativelyhighvisitorusecomparedtootherportionsoftheprojectarea.J453410/78408207-37 'l],JJ]']JVisualimpactsofprojectdevelopmentfocusmainlyontheintrusionintothewildernesssettingofroads,transmissionlinesandaccessroads,whichwillbehighlyvisible,particularlyfromtheairasrecreationistsflyovertheareatotheLakeClarkNationalPark.ChangesinexistingwaterlevelmaydetractfromaestheticvalueofthelakeandChakachatnaRiver;thiswouldbevisibletopeopleinairplanesandthoseusingthelakesandrivers.72.5.2TerrestrialResourcesThevegetationonthesteepslopessurroundingLakeChakachamnacanbegenerallyclassifiedastallshrublandwithalpinetundraandbarerockathi~herelevations.TheChakachatnaRivercanyonandthefloodplainofr1versflowingintoLakeChakachamnaarealsocoveredbytallshrubcommunities.Largelow-shrubbogsarefoundonflat,poorlydrainedareasasthetopographyflattensouttotheUpperCookInletcoastalplain.Sedge-grasscoastalma1;'shescovermostoftheareawithineightmilesofCookInlet,aswellassomeareasalongtheMcArthurRiver.Intermediatebetweenthecoastalmarshesandthebogsarepoorlydrainedareasofblackspruceforest.Theseareasdifferfromthebogsinthelackoffloatingvegetationmatsandtheabsenceofblackcottonwood.ThelaketapofLakeChakachamnawithadiversiontunneltotheMcArthurRiverbasinwouldnotresultinapermanentremovaloflargeacreagesofhabitat;butmodificationofhabitatwouldoccurintheconstructionofabout130milesoftransmissionline.TheLakeChakachamnaprojectinvolveswildlifecommunities1ntwpdistinctareas:(1)theanimalsaroundthelakeitselfand,(2)thewildlifeoccupyingther1verdrainagesflowingoutofLakeChakachamnaandtheMcArthurRiver.Thereforethesiteanalysisforthisprojectwilldiscussthewildliferesourcesinbothareas.LakeChakachamna.Mooseinthelakeregionfrequentthesubalpineandalpineshrubcommunitiesin,thespring,summer,andfall.Inthewinter,theanimalsdescendintother1par1ancommunitiesontheJ,453410/78408207-38 ],]floodplainsofriversflowingintothelake,and~ntheriparianhabitatadjacenttothelake(Bechtel1983).BrownBearintheareaheavilyutilizethehighaltituderiparian~onesandsubalpinemeadowsfound~nthesurroundinghighlandsandmountains.Blackbearsmainlyusetheuplandalderthicketsonthesteepslopesalongthelakeandtheripariancommunitiesonfloodplainsofr~versflowingintothelake(Bechtel1983).Dallsheepoccurathigherelevations,mainly~nthemountainousareasnorthoftheChilliganRiver(AEIDC1974).Theriparianzonearoundthelakeandinstreamdrainagesisimportantfurbearerhabitat--supportingmainlywolf,wolverine,mink,andotter.Thelakeprovidesnestingandrestinghabitatforlocalmigratingwaterfowl.Baldeaglesnestinthestreamdrainagesadjacenttothelake(AEIDC1974).DownstreamintheChakachatnaandMcArthurRivers.MooseutilizetheriparianhabitatthatoccupiesthefloodplainoftheChakachatnaRivercanyon,andblackcottonwoodripariancommunityfoundalongtheshoresoftheMcArthurandChakachatnaRivercanyonsandalongtheshoresofmoststreamsandsloughs.Theseareasareimportantaswinterrange,especiallytheupperMcArthurRiverdrainageandlowerreachesoftheChakachatnadrainage(Bechtel1983;ADF&G1976).BlackbearmainlyusetheuplandalderthicketsonthecanyonwaLlsabovetheMcArthur,ChilliganandNagishlaminarivers,andthehighaltitude'ripariancommunityintheChakachatnaRivercanyon.ThebearsusetheupperreachesoftheMcArthurRiver(areasouthofBlockadeGlacier)forsalmonfishing.iq.thespring.Brownbears.mainlyusethehighaltituderiparianhabitat~ntheChakachatnaRiver,descendingtotheriverfloodplaininthesummertotakeadvantageofspawningsalmoninthedrainage(Bechtel1983;ADF&G1976).453410/78408207-39 )\1)Cl)1.J]Theblackcottonwoodr~parl.anvegetationprovideshabitatformostofthefurbearerspresentinthearea.Mink,beaver,andmuskratarecommoninthisvegetationcommunity,whilecoyotesfrequentthecoastalriparianareasandwolvesthehighaltituderiparianzones(Bechtel1983;ADF&G1976).TheupperreachesoftheMcArthurRiverprovidenestinghabitatfortrumpeterswansandbaldeagles(Faro1984).TheTule'swhite-frontedgoosehasbeenreportedtousetheMcArthurRiverasmoltinghabitat(Faro1984).Thissubspecieswasproposedforthreatenedorendan~eredstatusin1981butwasnotacceptedforeithercategory(Money1984).Becauseofthelowpopulationofthissubspecies,thebirdspresentinAlaskahavebeenthesubjectofamonitoringprogrambystateandfederalresourceagencies.ThelowersectionoftheChakachatnaRiverprovidesnestinghabitatformanyspeciesofwaterfowl,swansandbaldeagles(Bechtel1983;ADF&G1976).TheamountofhabitatlostordisturbedduetotheLakeChakachamnahydroprojectwDuldbeapproximately3,440acres(Table2).TheprojectwouldadverselyaffectbrownbearuseofsalmonspawningareasontheChilliganandChakachatnar~vers.ThereducedflowofwaterdowntheChakachatnaRiverwouldhaveeventual,long-termimpactsonmoose,furbearers,andwaterfowl.Thestabilizationofr~verandsloughbankswouldallowthevegetationtodevelopandmature.Thiswouldresultintheeventualloss(throughplantsuccession)ofearlysuccessionalvegetation-areasofcriticalimportancetolocalmooseandfurbearers.Thedecrease~nr~verflowmayalsoresultinadewateringofareasusedasnestinghabitatbywaterfowlandswans.Increasedaccess,andtheprobable~ncreaseinhuntingandotherhumanactivities,wouldimpactlocalwildlife.453410/78408207-40 1j]7.2.5.3AquaticResourcesExtensivefisheriesstudieshavebeenconductedbythePowerAuthority1nrelationtotheproposedChakachamnaproject.ThereportpreparedforthePowerAuthorityin1983(Bechtel1983)summarizedthesestudiesasfollo~s:"Fieldobservationsidentifiedthefollowingspecies1nthewatersoftheproject(Chakachamna)area:,11r1J,]Resident:Anadromous:RainbowtroutLaketroutDollyVardenRoundWhitefishPygmyWhitefishChinooksalmonChumsalmonCohosalmonEulachonLongfinsmeltArticgraylingSlimysculpinNinespinesticklebackThreespinesticklebackPinksalmonSockeyesalmonDollyVardenRainbowsmeltBering'cisco\J1,J,!Salmonspawning1ntheChakachatnaRiverdrainageanditstributaries(Exhibit7)occursprimarilyintributariesandsloughs.Arelativelysmallpercentageofthe1982estimatedescapementwasobservedtooccurinmainstemorside-channelhabitatsoftheChakachatnaRiv~r.Thelargestsalmonescapement1ntheChakachatriadrainagewasestimatedtooccur1ntheChilliganandIgitnar1versupstreamofLakeChakachamna.(Someofthespawningareasarewithinthedrawdownzone,oftheimpoundmentandwouldbeimpactedbywaterlevelchanges).Theescapement'ofthosesockeyein1982wasestimatedtobeapproximately41,000fish(Table3),orabout70percentoftheescapementwithintheChakachatnadrainage.LakeChakachamnaisthemajorrearinghabitat)453410/78408207-41 -'IrlcJ:]JIJ1,J:Jforthesesockeye.Italsoprovideshabitatforlaketrout,DollyVarden,roundwhitefish,andsculpins.Inthe-McArthurRiver,over96percentoftheestimatedsalmonescape-mentoccurredintributariesduring1982.TheestimatedescapementofsalmonofallspecieswasslightlygreaterintheMcArthurthantheChakachatnadrainage.Otheranadromousfishincludingeulachon,Beringcisco,longfinsmelt,andrainbowsmelthavebeenfoundintheMcArthurRiver.Thecontributionofsalmonstocksoriginating~nthesesystemstotheCookInletcommercialcatch~spresentlyunknown.AlthoughsomecommercialandsubsistencefiShingoccurs,theextenttowhichthestockisexploitedisalsonotknown.Rearinghabitatforjuvenileanadromousandresidentfish~sfoundthroughoutbothrivers,althoughthewaterswithintheChakachatnaRivercanyonbelowLakeChakachamnaandtheheadwatersoftheMcArthurRiverdonotappeartobeimportantrearinghabitat.Thereappearstobeextensivemovementoffishwithinandbetweenthetwodrainages,andseasonalchangesindistributionhavealsobeennoted."ThePowerAuthorityhasconcludedthatfishpassagefacilitieswillbeneededforthisprojecttomaintainthepopulationofsockeyethatspawnaboveLakeChakachamna.Thesuccessofthesefacilitiesformaintainingupstreamanddownstreampassageisuncertain.Onaworstcasebasis,allofthesefishwouldbeeliminated.ThepopulationestimateforadultsalmonutilizingareasontheChakachatnaRiverdownstreamofthedamsiteandontheMcArthurRiverisapproximately64,000fiSh(Table3).ThePowerAuthoritysuspectsthatflowreductionsintheChakacrratnaRiverduetodiversionofwatertotheMacArthurdrainagewillpotentiallyhavesignificanteffectsopmainstemandside-channelfiShhabitatsinbothrivers.Forexample,theNoauktaSlough~nthelower453410/78408207-42 1J]Jj1JChakachtnaRiverisaknownrearingareaforsalmonids.Changesinflowreg1.mesthroughthisareacouldsignificantlychangethisfishhabitat.Informationontheextentofhabitatgainsorlosseshavenotbeendetermined(Bechtel1983).ThediversionofwatertotheMacArthurRivercouldalsoresultinpotentialmiscueing,straying,and/ordelayofanadromousfishthatnormallyspawnaboveLakeChakachamnaduetoreleaseofolfactorycuesattheMcArthurpowerplanttailrace(Bechtel1983).Thiscouldresult'inasignificantimpacttothesefish.Thetotalnumberofadultsalmonthatcouldbeimpactedbythisprojectisover100,000.Thisincludesbothfishupstreamanddownstreamoftheproject(Table3).7.3ComparisonofHydroAlternativeswiththeProposedProject7.3.1SocialSciencesSocioeconomicsTheProposedProjectwillhavefewersocioeconomicimpactsthanacombinationofthehydroalternatives(Table4)becausethenumberofinmigrants,ithefactorthatdrivesmostothersocioeconomicimpacts,1.SexpectedtobelessforSusitna.Thealternativeswouldaffectalargernumberofsmallcommunitiesthatareespeciallyvulnerabletofiscal,communityserV1.ces,housing,andquality-of-lifeimpacts.ThenumberofpredominantlyNativeAmericancommunities(includingTanacross,DotLake,andTyonek)susceptibletoqualityoflifechangesisalsogreaterforthealternatives.LandUseIngeneral,theProposedProjectwillhavefewerlandutilizationimpactsthanthecombinationoftheotherhydroalternativesbecausetheimpactsonrecreationalaswellasadjacentsettlementlandswillbecontainedinonej.453410/78408207-43 J1JJ)J1Jarea(Table5).Incontrast,undertheDEISpreferredalternative,impactsonrecreationandadjacentsettlementlandswouldbewidelydispersedthroughouttheState.Withregardtoactualcategoriesoflanduse,itisimportanttonotethattheJohnsonsitealonewouldinundate94,500acresofland,twocommunities(populations67and200),portionsofanexistinghighway,pipelineandtelephoneline,ahighwaymaintenancestation,threegravelpits,twogagingstationsandalodge.ThisisextremelyseverecomparedtotheProposedProjectIsexpectedinundationof43,000acresforbothWatanaandDevilCanyonandsixstructures(fourcabins,twoofwhicharenolongerinuse,onelean-to,andonecollapsedbuilding).Withrespecttolandownership,theJohnsonandBrowneprojectswouldposedifficultproblemsduetothecomplex,multipleownershippatternsinandaroundtheprojectsites.TheBrownereservoirwouldalmostcompletelyinundatetheHealyAgriculturalSubdivisionaswellasmanyprivatetractsandoneminingclaim.Inaddition,theaccessandutilityrouteswouldcrossprivatedisposaltracts.Similarpr;oblemswouldoccurwiththeJohnsonsitewherethelandsareownedbytheState,Federalgovernment,Nativegroups,andNativeandnon-Nativeindividuals.AlthoughlandownershiparoundtheProposedProjectsite1Salsocomplex,ongoingnegotiationsareaimedatresolving1ssuesofownershipanduse.Thecomplexanddiverseownershipsoftheaccessroutesand.utilitycorridorsforallnon-Susitnahydroalternativesmaymakeoutrightpurchasesorrights-of-waydifficu1.ttoacquireforanyproject-relatedpurposes.Thisa~pliesparticularlytotheChakachamnahydroalternativewhereit1SalreadyknownthattheTyonekNativeCorporationhasapolicyofrefusingeasementsandright-of-wayontheirland.Ownership~lsoaffectsareamanagementplans.Wherehugetractsaroundasiteareinsingleownership,asisthecasefortheSnowsite,locatedintheChugachNationalForest,theprojectmayposelessconflictwithexistingmanagementplans.Wherethereiscomplex,small-tractownership453410/78408207-44 1JJljIJaswiththeJohnsonandBrownesites,thedevelopmentofthesitewouldlikelyposegreaterconflictswiththeplansthatsomeownershavefortheirproperties.CulturalResourcesImpactstoculturalresourcesfromthenon-SusitnahydroalternativescanbeexpectedtofarexceedthosefromtheProposedProjectalone(Table6).OnlytheProposedProjectareahasbeensubjectedtointensivefieldstudiesdesignedtolocateallpotentiallysignificanthistoricandarcheologicalsites.However,apreliminaryanalysisoftheotherhydrositelocationsindicatesthatallarelikelytocontainpreviouslyunrecordedresources.TheJohnsonsitealone,byvirtueofthesizeoftheimpoundmentcomparedtothatfortheProposedProject,andthegrossenvironmentalsimilaritybetweentheareas,islikelytocontainmorearcheologicalsitesthanthoserecordedtodatefortheProposedProject.Impactsandnecessarymitigationmeasurescanlikewisebeexpectedtp.beproportionatelygreater.ImpactsattheBrowne,Keetna,andSnowsites,becauseoftheirsmallerdirectimpactareasmightbeexpectedtoaffectfewerculturalresources.Impactsandmitigationwould,however,bequalitativelysimilartothatattheProposedProject.Chakachamna,becauseitdoesnotincludeanimpoundment,anddirectlyaffectsasmallerarea,canbeexpectedtohavetheleastsignificantimpactonculturalresources.RecreationSummarycomparisonsofalternativeimpactswithimpactsoftheProposedProjectarepresentedinTable7.Impactstorecreationalresourcesfromthetotal.non-SusitnahydroalternativescanbeexpectedtofarexceedthosefromtheProposedProjectalone.Bothindividuallyandcombined,thehydroalternativeswouldimpactmoreexistingrecreationthantheProposedProject.Thisisduemainlyto453410/78408207-45 1)...~]IJ1...J]...Jthoseareasscen1Cquality,proximitytotravelroutes,nationalparksandnationalforests.ThehydroalternativeshavethepotentialtoimpacttwoNationalParks,oneNationalForest,threeriversrecommendedforState.protection,andnumeroussmallsitesrecommendedforStaterecreation.Inaddition,boatingactivitieswouldbeimpactedonfiveriversinsteadofoneandseveralstatedesignatedorrecommendedsites/areaswouldbeimpactedcomparedtononefortheProposedProject.MajorsightseeingrouteswouldbeimpactedbyBrowneandJohnsonsitescomparedtononefortheProposedProject.RecreationdemandforthecombinedhydroalternativeswouldbesubstantiallyincreasedoverthatfortheProposedProject.Furthermore,thecostsassociatedwiththeoperation,maintenance,andmanagementofr.ecreationfacilitiesdevelopedforthehydroalternativeswouldlikelyex~eedthoseoftheProposedProject.AestheticResourcesSummarycomparisonsofalternativeaestheticimpactswiththoseoftheProposedProjectarepresentedinTable8.Impactstoaestheticresourcesandvisualsensitivityimpacttoviewersfromthetotalnon-SusitnahydroalternativeswouldbemucngreaterthanthatfortheProposedProjectalone.TheBrowneandJohnsonsiteswouldpresentparticularlysignificantvisualimpactsduetocuttingandfillingrequiredtorelocatethehighways,railroad,transmissionlines,andpipeline.Also,theseverityofimpactswouldbegreaterduetotheproximityofthemajortravelroutestothereservoirs,whichwouldprovideviewsoftheextensivemudflatscreatedbybothBrowneandJohnson.Furthermore,theBrownereserV01randassociatedfacilitieswouldbevisiblefromareas1ntheDenaliNationalParkandPreserve.TheSnowsite1Sprobablythemostscenicofallthehydrositesbecausetheprojectwouldbelocatedinawildernessareawithsteepterrain,glaciers,andforests.Visualimpactsassociatedwiththealternativestransmissionlineswouldbegreaterduetomoremilesoflinesinproximitytomajortravelroutes•I.J453410/78408207-46 ]]]JJ].JVisualimpactsresultingfromlandclearinganddisturbancewouldbemuchgreaterwiththealternativehydrositesthanwiththeProposedProjectbecauseofthegreateramountandhighervisibilityoftheareas.7.3.2TerrestrialResourcesCo~structionofthevariousdams,impoundments,diversions,laketaps,andassociatedfacilitiesattheJohnson,Keetna,Snow,Browne,andLakeChakachamnasiteswouldresultinthepermanentor,temporaryremovalofabout125,000acresofhabitat(Tables2and9).TheProposedProjectwouldresultintheinundationandcompleteorselectiveclearingofmorethan56,000acresofhabitat(FERC1984).Access,arisingasaresultofconstructionactivities,mayresult1nlong-termor"permanentimpactsonthelocalwildlife.Animalpopulations1npreviouslyunroadedareassuchastheproposedKeetnaandSnowsiteswillbecomesubjecttogreaterhunting,poaching,andtrappingpressures.Evenwithstrictenforcementofexistingfishandgamelaws,thespecificimpactsar1s1ngfromincreasedaccessibilitywouldbedifficulttoassess;butchangesinmovementpatternsandhabitatusewilloccurformostspecies.Themainhabitattypeaffectedbythenon-Susitnahydroalternativesistheripariancommunitiesassociatedwithriverfloodplain$andstreamdrainages.These·areasareespeciallyimportanttomooseinwinterandduringcalvingseasons.Loss"ofthesehabitattypeswillresultineitherincreasedmortalities,oremigrationsfromtheareas.TheJohnsonhydroelectricprojectcouldseriouslyimpactthemoosepopulationintheregion.No.recentburnshaveoccurredneartheimpoundmentarea,thereforemostwinterbrowseisprovidedbystreamsidewillowstandswherethefloodinganddisturbanceassociatedwiththerivermaintainstheearly-successionalshrubcommunity.TheJohnsonprojectcoulddrasticallyreducethemoosepopulationintheDotLakeregionbyeliminatingcriticalwinterfoodandcalvingareas.453410/78408207-47 ']]]]JThealternativeimpoundmentzonesandgenerationfacilitiesweregenerallyoflimitedimportancetoDallsheepandcaribou.Theanimalseitheroccupiedareasremovedfromtheimpoundmentzonesand-facilities,orutilizedsuchawide'rangeofterritorythattheimpactedareaswerelittleused.Theeliminationoflowlandshrubcommunitiesineachalternativeprojectareawouldaffectbothspeciesofbear.ThelossofshrubhabitatattheJohnsonsitewouldeliminatespecialuseareas(e.g.theBillyCreekdrainage)neededbythelocalblackbearpopulation.TheProposedProjectwouldnotimpactsalmonspawningareasabovethedamsite,becausevirtuallynoneexist.However,theKeetnaprojectwouldseverelyimpacttheimportantsalmonrunsintheupperTalkeetnaRiveranditstributaries,especiallythoseonDisappointmentCreekandPrairieCreek.PrairieCreekisconsideredaseasonallyimportantcriticalhabitatforbrownbearsinthemiddleSusitnaBasinduetothechinooksalmonfisherythatthebearsutilize.TheChakachamnaprojectwouldaffectsalmonspawningareasintheChilliganandChakachatnaRivers,;:llsoareasofhighimportancetobrownbears.Theriparianvegetationatalldamsitesprovideshabitattothemajorityoffurbearerspeciesfoundinthestate.Lossoftheseareaswouldeliminatecriticalfurbearerhuntinghabitatandmovementcorridors.Exactpopulationdata-detailingthepopulatio'nlevelofmajorfurbearersintheimpoundmentareasarenotavailable.TheJohnson,Browne,Keetna,andSnowimpoundmentswouldinundateknownorpostulatedraptor(includingbaldeagle)nestlocations.AlthoughtransmissionlinesrelatedtotheProposedProjectwouldpassabout1.5milesfromahistoricperegrin~falconnestlocation,thisfacilityisnotexpectedtoaffectperegrinefalcons.However,theJohnsonprojectmaysignificantlyimpactuptofourperegrinefalconnestinglocationsthat453410/78408207-48 J]occuralongtheshorelineoftheimpoundment.Threeofthesefourlocationswererecordedasactivein1983.W~terfowluseoftheProposedProjectareaislow,asisthewaterfowluseoftheBrowne,Keetna,andSnowhydrosites.TheJohnsonsitecontainsimportantwaterfowlhabitatformigratingandnestingducks,geese,andsandhillcranes.TheChakachamnahydrositeandassociatedriverdrainagesencompassareasusedasswan,duck,andgoosenestinghabitat.7.3.3AquaticResourcesTable10presentsasummaryoffisheriesresourcesassociatedwiththenon-SusitnahydroalternativesandtheProposedProject.Ifallnon-Susitnahydroalternativesaredeveloped,thepotentialimpacttoaquaticresourceswouldbe·significantlygreaterthanpotentialimpactsduetotheProposedProject.Thereasonsforthisare:]]~-11.Jj1.453410/7840820Twoofthesites(ChakachamnaandKeetna)areknowntohavehighlyimportant.anadromous.fishrunsupstreamoftheprojectsite.These"runswouldrequirepassagefacilitiesforupstream·anddownstreammigrants.Theeffectivenessofthefacilitiesisuncertain.Onaworstcasebasis,thefacilitieswouldnotworkandallanadromousrunsupstreamofthedamswouldbeeliminated.TheChakachamnaprojectalsoinvolvesthediversionofwaterfromoner~versystemtoanotherwhichwouldsignificantlydisruptmigratorypatterns.Incontrasttothenon-Susitnahydroalternatives,alloftheanadromoussalmonintheSusitnaRiverspawndownstreamoftheProposedProjectsite(exceptforafewchinooksalmonthatareabletopassthroughDevilCanyon).Therefore,passagefacilities,withtheirpotentialriskforsuccess,willnotbeneededfortheProposedProjectsite.7-49 ]].1JIJ2.AnadromousfishalsoareknowntospawnupstreamoftheBrowneandJohnsonimpoundmentzones.Althoughescapementnumbershavenotbeenestimated,itishighlylikelythatpassagefacilitieswouldberequiredatbothsites.Aswithothersites,itisuncertainifsuchfacilitieswouldbesuccessfulinpassingfish.Thesefishcontributetothehighlysignificantcommercial,subsistence,andsportfisheriesdownstreamofthesiteinthelowerTananaandYukonrivers.Thecombinedimpactsofthesetwoprojectswouldalsoneedtobeconsidered.3.LossesofknownsalmonspawningareaswithintheKeetna,Johnson,andChakachamnaimp~undmentsmayneedtobemitigated.4.LowerParadiseLake,asitethatsupportsanexistingrecreationalfisheryintheSnowRiverdrainage,wouldlikelybeinundatedbyturbidwatersoftheimpoundment.5.Eachalternativesitewouldrequiremitigationforimpactstodownstreamspawningandrearingareas.Theseimpactscouldresultfromchangesin.flow,waterquality,spawningandrearinghabitats,gassupersaturationandothers.Themitigationfortheseimpactscouldincludeeithermaintenanceofinstreamflowrequirements,habitatmodification,orartificialpropagation.6.EachsitepresentspotentialimpactstofisheriesresourcesthatareasgreatorsignificantlygreaterthanthoseoftheProposedProjectsite,particularlyiftherelativeimpactstoeachindividuallyproposedprojectareaareconsidered.Ifallsitesweredeveloped,thepotentialimpactswouldbefarmoreextensivethanProposedProjectimpactsandthemitigationrequiredwouldalsobemuchmoreextensive.JOneofthePowerAuthorityIskeyscreeningcriteria(Acres1981)avoidplacingadamatapointwhereupstreammigrationoccurs,wastothereby453410/7840820'7-50 Cl,J]]], Jcompletelyavoidingtheuncertaintiesofsuccessofupstreamanddownstreampassagefacilities.TheProposedProjectsites(WatanaandDevilCanyon)meetthiscriterion.Thehydroalternativesdonotmeetthiscriterionbecausehighlysignificantsalmonrunsareknowntoexistabovetwoofthesites(KeetnaandChakachamna),runsofunknownsizeexistabovetwoothersites(BrowneandJohnson)andrunsmayexistabovethefifthsite(Snow).Therefore,thealternativehydroscarrythewell-knownrisksassociatedwithattemptingtoprovideupstreamanddownstreampassage.Althoughsuchfacilitieshavebeenpartiallysuccessfulatotherdams,therehavealsobeensignificantfailureswhereupstreampassageisnolongerviableandothermeansofmitigation,primarilyhatcheries,havebeenrequired.Insummary,theKeetnaandChakachamnaprojectsclearlyputimportantsalmonrunsupstreamofthesesitesinjeopardyofelimination.Inaddition,althoughnonumbers'canbeestimatedfromcurrentinformation,theBrowneandJohnsonsitesplacetheanadromoussalmonrunsabovethesesitesatriskofelimination.Incontrast,theProposedProjectputsnoupstreamanadromousrunsatriskbecausevirtuallynonearepresent.]J453410/78408207-51 ,J,J'jj8.0CostComparison-AlternativeSitesvs.ProposedProject8.1IntroductionProjectconstructioncostsbasedonJuly1980levelsweredevelopedbytheApplicantforthepurposeofcomparingdifferenthydroprojectalternatives.Thesecomparisonswerepresentedinthe"DevelopmentSelectionReport"(DSR)(Acres1981)whichbecamepartoftheFERCLicenseApplication.Subsequenttotheselectionprocess.thePowerAU~horityproceededtoupdateanddetailSusitna(WatanaandDevilCanyondams)constructioncoststoaJanuary.1982.level.Alternativeprojectcostswerenotupdatedbecausetheselectionprocess,madeonacommoncomparativebasis.hadalreadyindicatedthattheProposedProjectwasthemostfavorablealternative.The1982costfortheProposedProjectwasapproximately95percenthigherthanthe1980estimate.FERCStaff.l.ntheirpreparationoftheDEIS.usedtheJanuary.1982levelPropoliedProjectcostwhenpresentingtheircostcomparisons•AlternativehydroelectricprojectsconsideredwereBrowne.Johnson.Keetna.Snow.andChakachamna.Inpresentingthosecomparisons.FERCStaffdidnotrevisetheDSRalternativesIcoststomakethemcomparabletotheProposedProjectcost.Hadtheyescalatedthealternatives'coststoagreewiththeProposedProjectcosts,avalidcomparison,couldhavebeenmade.8.2DEIS1982LevelCostDevelopmentTheDSRandDEISprojectconstructioncostsaresummarizedbelow.TheapparentescalationfactorsusedforcomparisonpurposesbyFERCStaffar~showninthefollowingtable.453410/88408208-1 ]'JDSRCostDElSCost:JJApparentProject(1980Leyel,(1982Level,Escalation,Alternatives$x106)$x106)DSRtoDElSBrowne624.516819%increaseJohnson896.921./3192../64%decreaseKeetna476.655199%~ncreaseSnow254.6130520%~ncreaseChakachamna1,480.4190539%decreaseAlternativesTotal3,733.102,72927%decreaseProposedProject2,8605,565..------95%~ncrease]1./2../]./AcostforJohnsonwasnotincludedintheDevelopmentSelectionReport(DSR).ThecostshownwascomputedusingDSR.quantityestimatesandunitcostsforBrowne,KeetnaandSnow.Basisforcostpresented~nDElSunknown.DElScostsused"byFERCStaff;$5565millioncostfortheProposedProjectisacheckestimatewhichwasincludedintheJuly11morecurrentestimate(bythePowerAuthority)of$5150millionwaspresentedastheLicenseApplicationcost.1SupplementtotheLicenseApplicationforcomparisonpurposes.AlTwoobservationsareapparentfromtheabovecomparison.First,thereisno_1commonescalationfactorforthehydroalternatives.Second,thetotal453410/88408208-2 j'1Jalternativescosthasbeendecreasedalmost30percentfromthatpresentedintheDSR,whileatthesametimetheescalatedcostoftheProposedProjectnearlydoubled.AvalidconclusionbasedupontheDEIScostcomparisonisnotpossibleusingthecostsshownabove.8.3DevelopmentofaCommonEscalationFactorTheJanuary1982level,escalatedcostsfortheProposedProjectwerebasedonadetailedcostanalysisusingmorerealisticunitprices.Itwouldappearreasonabletoassumethat,ifacostreevaluationhadbeenmadeforeachofthealternativehydroprojectsusingthesameamountofdetailandcomparativeunitprices,theyalsowouldhaverealizedasimilartotalcostescalationofaround95percent.8.4AdditionalCostofTransmissionIntertieInclusionoftransmissionintertiecosts,whichwereomittedintheDElS,wouldhaveasignificantimpactupontheeconomicsofthenon-Susitnahydroalternatives.Therequiredtransmissionfacilityisconsideredtobe"comparabletothatrequiredfortheProposedProject,andwillhaveacomparabiecostaswell.Anexactcostisnotavailableatthepresenttime,althoughroughestimatesindicatethecostwouldbeintherangeof$475million.TheadditionaltransmissioncostsoftheSusitnahydroprojects~snotincludedinthe1982levelcostcomparisonpresentedinthefollowingconclusions.8.5ConclusionsBasedonthemorevalidJanuary,1982,costsshown1nTable11,thealternativeprojectswouldcost$7,264x106,whichisconsiderablymorethanthecostofSusitna($5,565x106).Tables11and12comparetheindividualprojectsandthecombinedalternativeandProposedProjectcosts453410/88408208-3 j]1jandstatistics.ItisreadilyseenthattheJanuary,1982,levelunitcostperinstalledMegawattfortheProposedProjectis$3.44x106-lessthanhalfofthe$9.05x106forthealternatives.453410/88408208-4 I'J]..Jj9.0PowerAndEnergyProduction9.1IntroductionTheaverageenergyproductionofthealternativesitesshownonTable1-18oftheDEISwasanalyzedwiththeU.S.ArmyCorpsofEngineersHEC-5computerprogramusinghistoricstreamflowdataforeachriverbasinalongwithminimumsummerflowrequirementsasgiveninTable2-7oftheDEIS.FERCStaffinformation(letterdatedAugust7,1984fromFERCtoApplicant'sCounsel)statesthattheHEC-5programwasusedtosimulateeachprojectindividuallyfortheyearsofavailablestreamflowdata.Energyproductionwasdeterminedfromatargetmonthlyplantfactorandprojectedminimumflowconstraintsweremodelled.TheHEC-5programcalculatedmonthlyenergyproductionaswellasmaximumavailablecapacity.Itisnotknownhowthetargetmonthlyplantfactorwasselectedandwhyitwassetasitwas.UnlesstheproductionofcapacityandenergybythevarioushydroelectricplantsthatwerestudiedwasrelatedtothemonthlyandannualsystemloadrequirementspresentedintheLicenseApplication(ExhibitBVolume2ATablesB.74throughB.77andB.lOO),theresultsobtainedprobablyareerroneous.Therefore,thestudiesdescribedinthissectionweremadetochecktheDEISestimatesofaverageannualenergyproductionandtocomputethedependablecapacityofeachalternativesitegiventheminimumflowconditionspresentedintheDEIS.ThePowerAuthoritydoesnot'necessarilyagreewiththeminimumflowspresentedinDEISTable2.7.However,forconsistencyandcomparisonpurposes,theflowsinTable2-7wereusedinthefollowingpowerandenergyanalysis.ThebasicdataforthefivealternativesitesandtheProposedProjectareshownonTable14.ThepowerandenergyproductionoftheProposedProjectisbasedonflowregimeCandtheoperatingrulecurvecontained~ntheLicenseApplicationExhibitBVolume2•.ThepowerstudyforChakachamnaAlternativeEcouldnotbecompletedbecausetheminimumflowrequirementsforChakachatnaRiverintheDEIScouldnotbe)J453410/98408209-1 1IIsatisfied.Therefore,thepowerstudywasmadeforAlternativeD(Bechtel1983).AlternativeE,whichwasrecommendedintheReport,was'consideredinSections4.0,5.0,6.0,7.0and8.0ofthisAppendixforconsistencyanddirectcomparisontotheDElS.AlternativeDconsistedofarpckfilldamattheoutletofChakachamnaLake,apowerhouselocated12milesdownstreamontheChakachatnaRiver,andatunnelconnectingthereservoirandthepowerhouse.Thedamwouldhaveacrestlengthofabout600ft.VerticalFrancisturbines,withatotalcapacityof300MW,wouldbeinstalled.Theplantfactorwouldbeabout50percent.Thetunnelwouldbe12mileslongand25feetindiameter.9.2HistoricStreamflowRecordTheeeriodsofhistoricmonthlystreamflowusedinthepowerandenergysimulationsofthenon-Susitnahydroalternativesarepresentedbelow:]:JAlternativeProjectBrowneJohnsonKeetnaSnowChakachamna9.3MinimumFlow1nSummerSimulationPeriod(yrs)2922142730J)IMinimumsummerflowrequirementsinJune,July,andAugustwereproposed1ntheDElStoreduceimpactsonfishmigrationandspawningactivities.TheseminimumsummerreleaseswerebasedonthemaximumofthehistoricalQ90valueinthosethreemonths.(ThemaximumofthehistoricalQ90valueistheflowforagivendaywhichisexceeded90percentofthetime(90453410/98408209-2 11J1,)1,Jpercentileflow)andwhichisgreaterthanthe90percentileflowsforallotherdaysofthethreemonthperiod.)ThemonthlyaveragesofhistoricalflowsandtheminimumreleasesinJune,July,andAugustforeachalternativesiteareshowninTable15.AtJohnsonandChakachamna,themonthlyaveragestreamflowislessthanorclosetotheminimumrelease.Thismeansthattherewouldbenowaterstoredinthesummerofanaverageyearandtherewouldbestoragewithdrawalinthesummerofadryyear.AtBrowneandKeetnathesummerminimumrelease~salargepercentageoftheaverageinflow,andlittlewaterwouldbestoredinayearofaverageorlowinflow.Therefore,theseasonalregulationofflowsbythereservoirswouldbelimitedandinlow-flowyearswintergenerationwouldbeminimal.Onlythesmallestsite,Snow,couldstoreareasonablepercentageofsummerinflow.9.4EnergyProduction~ntheSummerPotentialpowerandenergyproductionduringthesummer~slimitedbytheproposedinstalledcapacityatmostofthesitesandhastobecheckedagainsttheabilityoftheRailbeltpowersystemtoabsorbtheproduction.Thetotalpowerplantoutputforallfiveprojectsbasedontheminimumflowrequirements~nthesummerisover1,110MW(Table16).However,theinstalledcapacityoftheplantslimitsthetotalpowerproducedto773MWwhichis68%ofthecapacityobtainedfromtheminimumsummerreleasesat100%loadfactor.Table17showsthemax~mumhydrauliccapacityandthesummerminimumreleaserequirementsforeachalternativedevelopment.FortheBrowne,Johnson,andChakachamnasitestheinstalledhydrauliccapacityislessthantheminimumflowrequiremen~s.Therewouldbeatheoreticallossofenergyduetolimitedcapacitybecausepartoftheminimumflowmustbereleasedthroughvalvesoroveraspillway.However,Table18,whichisdiscussed~nthenextsection,showsthatthesystemcouldnotutilizeadditionalenergyevenintheyear2010,andadditionalturbinedischat::gecapacitywouldnotincreaseenergyproduction.453AlO/98408209-3 ')JI'IJ'1].J1jjUndertheApplicant'sReferenceCaseforecast,thesummerenergycouldnotbecompletelyusedbytheRailbeltsystemuntilsometimeaftertheyear2020,evenaslimitedbyinstalledcapacity.9.5MonthlyDistributionofEnergyTheminimumreleaserequirementsforthealternativehydrositesselectedintheDEIScorrespondcloselytothehydrologiccyclesinthesebasins,whicharecharacterizedbyhighflowinthesummerandlowflowinthewinter.However,theRailbeltenergyrequirementistheopposite;lowinthesummerandhighinthewinter.IftheDEISminimumflowsconstrainoperation,seasonalregulationofflowwouldbelimitedandmostoftheenergyfromeachsitewouldbeproducedduringthesummerwhentheenergyrequirementsarelow.Sincewaterstoredinthereservoirforwintergenerationwouldbelimited.ornon-existent,winterenergygenerationwouldbesignificantlyreducedandthedependablecapacityofthenon-Susitnahydroalternativesiteswouldbereduced.Therefore,therequiredamountofthermal~apacityforwinteroperationmaybeasgreatasthatrequiredwithoutthealternativehydro.Thus,mostofthebenefitofthealternativehydrositeswouldresultfromdisplacingfuelwhichotherwisewouldbeusedforthermalgenerationduringthesummer.Littleornotthermalinstalledcapacitywouldbedisplaced.Inordertosimulateoperationofthealternativehydrosites,themonthlyReservoirOperationModel(RESOP)wasused.Theenergyrequired1nyear2010,assumingtheApplicant'sReferenceCaseForecast,wasusedastheupperlimitforenergyproduction.Theyear2010wasselectedforthisstudybecausebythatyearthenon-Susitnahydroalternativescouldallbeconstructed.Theenergyrequirementincluded10%transmissionlineanddistributionlossesandwasadjustedtoexcludetheaverageenergygeneratedfromexistingRailbelthydroelectricprojects(Eklutna;CooperLake;andBradleyassumedon-linein1988).Eachalternativewassimulatedseparately,startingfromthesmallestvolumereservoir(Snow)andending453410/98408209-4 'j1J'1j1JJ])1I"Jwiththelargest(Johnson).AseachreserVOl.rl.Soperated,theaveragemonthlyenergiesofthepreviouslysimulatedreservoirsaresubtractedfromthesystemenergyrequirement.Thereservoirbeingsimulatedhasitsenergyproductionlimitedbythismodifiedsystemenergyrequirement.ThisseverelylimitedtheenergythatcouldbeproducedinthesummerbyJohnson,thelastreservoirtobesimulated,butJohnsonhasthelargestvolumeofstorageandthebestabilitytoregulateflowtothewintermonths.Table'18showsthemonthlyalternativehydroelectricenergyproductionwiththefiveplantsoperatedinorderofincreasingreserVOl.rvolume,startingwiththesmallest.Systemenergyrequirement,non-hydrorequirement,andspilledenergyonamonthlybasisarealsolistedforcomparison.Asameasureofsensitivityofoutputtotheselectedorderofplants,twoothercombinationswereanalyzed.Table19showsananalysisl.nwhichplantsareselectedinorderofstoragesizeintermsofdaysofmeanflow,startingwiththesmallestandsuccessivelyintroducinglargerplants.TheactivestorageindaysofmeanflowisshowninTable14.InTable20theprojectorderwasrearrangedwithChakachamnagivenfirstpriorityandfollowingsuccessivelybySnow,Keetna,andBrowne.JohnsonislargerthantheothersbutislistedattheendbecauseofitsundesirablylargereserVOl.rareaandquestionablefoundationconditions..Thetotalenergyproductionanditsmonthlydistributionareessentiallythesameastheresultsofthesimulationintheorderofstoragevolume(Table18).Table21showsacomparisonofaverageannualenergyascomputedbyHEC-5(fromDEISTable1-18)withthatcomputedbyRESOPforyear2010loadconditions.Thesameresultsfromthreedifferentarrangementsl.nsimulationshowsthatthepriorityofpowergenerationwithinthefivenon-Susitnahydroalternativeswillnotaffecteitherthetotalenergyproductionoritsdistribution.Thetwofactorsgoverningthetotalenergyproductionare.:(1)lowenergydemandandhighminimumreleaseinsummer,whichlimitthe1I'.J453410/98408209-5 ~1j]1Jenergyproductioninsummertothesystemrequirement,and(2)insufficientreservoirstorageattheendofthewetseason,whichseverelylimitstheenergyproductioninwinter.9.6DependableCapacityThegeneratingcapacityateachofthenon-Susitnahydroalternativesitesislimitedbybothhydrauliccapacity(asdiscussedinSection9.4)andwatersupply.TheannualpeakloaddemandsoccurinDecemberandJanuaryintheRailbelt.Theprojectedmonthlydistributionofenergydemand(ExhibitB,Volume2ATableB.75,LicenseApplicationJuly1983)showsthattheannualpeakisinDecemberalthoughitcouldbeinJanuaryinsomeyears.Inthisstudy,theaverageplantoutputinDecember,whichistheaverageenergyproductioninDecemberdividedbythenumberofhoursinthemonth,isconsideredasthedependablecapacityoftheplant.Thisdefinitionwasselectedbecausethesitesareonanadromousfishstreamsandhourlydischargefluctuationisnotassumed.Table22showstheresultingdependable'capacitiesforDecember.AsdiscussedinSection9.5,thewaterreleaseorenergyproductioninwinterissignificantlyreducedbecauseofhighr-eleasesinsummer.Likewise,thedependablecapacityinwinterwouldbemuchlessthantheplantcapabilitywhenavailablewatersupplyisconsidered.9.7ConclusionsIngeneral,theseasonalregulationofflowsbyther:eservo~rswouldbelimitedbythehighminimumflowrequirements~nsummer.AlargeamountofenergywouldbespilledintheinitialyearsofthealternativeprojectsIoperationbecauseoflowenergydemandandhighflowrequirementsinthesummer.However,asenergyrequirementsincreasewithtimemoresummer]453410/98408209-6 c1JJ.1JI.JenergycanbeabsorbedintheRailbeltsystem.However,winterenergysuppliedbythenon-Susitnahydroalternativeswouldnotincreasewithloadgrowth.TheaverageannualenergyproductionbyRESOPin2010,asshowninTable21,is21percentlessthanthatestimatedintheDEIS.Thereasonis thatthesimulationbyRESOPconsideredthefivealternativesasasystemandlimitedtheene~gyproductiontothemonthlysystemenergyrequirement,whereas,theDEISstudyconsideredthealternativesasindividualsanddidnotrelateenergyproductiontosystemdemand.However,assystemenergyrequirementsincreasebeyondthe2010level,theenergyoutputindicatedbyHEC-5canbeabsorbedintotheRailbelt.Roughcalculationindicatesthatalltheenergywouldbeabsorbedbyyear2025.FromTable18itcanbenotedthatonly27percentofthemonthlysystemenergyrequirement~nDecember2010issuppliedbythealternatives.Thisenergyproductiontranslatesdirectlyintothedependablecapacityofthealternatives.Thetotaldependablecapacityofallthenon-Susitnahydroelectricalternativesis260MWor34percentoftheirtotalinstalledcapacity.Thisvaluewouldnotincreasewithtime.453410/98408209-7 l'Jll]]]]]]10.0ReferencesAcresAmerican.1981.SusitnaHydroelectricProject,DevelopmentSelectionReport-Task6 -DesignDevelopment.Section6.4andAppendixC.PreparedfortheAlaskaPowerAuthority.AlaskaDepartmentofFishandGame.1976.AFishandWildlifeResourceInventoryoftheCookInlet-KodiakAreas.CompiledbytheAlaskaDept.FishandGamefortheAlaskaCoastalManagementProgram-Div.PolicyDevelopmentandPlanning.68pp.AlaskaDepartmentofFishandGame.1983.AnadromousWatersCatalogue.HabitatProtectionDivision.AlaskaDepartmentofNaturalResources1981.SusitnaBasinPlanningBackgroundReport.ScenicResourcesAlongtheParksHighway.1981.AlaskaDepartmentofNaturalResources:1982.TananaBasinLand-useAtlas,LandandResourcePlanningSection.DivisionofResearchandDevelopment.AlaskaDepartmentofNaturalResources.1983.TananaBasinAreaPlan.Fairbanks,AK.AlaskaDepartmentofNaturalResources.RecreationElement.StateofAlaskaSoilConservationService.1984a.TananaBasinAreaPlan,andU.S.Dept.ofAgriculture,1.J]AlaskaDepartmentofNaturalResources.1984b.TananaBasinAreaPlan.Fishandwildlifeelement~·Stat.eofAlaskaandU.S.Dept.ofAgriculture,SoilConservationService.453410/1084082010-1 l]'J]JJJ]1cJJ1JAlaskaDepartmentofNaturalResources.1984c.SusitnaAreaPlan,AgencyReviewDraftAnchorage,AK.AlaskaPowerAdministration.1980.HydroelectricAlternativesfortheAlaskaRailbelt.AlaskaPowerAuthority.1983a.SusitnaHydroelectricProject,ApplicationforlicenseforMajor'Project?ExhibitE,Chapter10,Volume9submittedtoFERC,Washington,D.C.AlaskaPowerAuthority.1983b.SusitnaHydroelectricProjectResponsestoAdditionalDataRequestsofJuly29,1983.ExhibitsBandD.AlaskaPowerAuthority.1983c.SusitnaHydro,electricProject,ResponsetoScheduleB,Item1,ofFERCLetterdatedAugust29,1983.ArcticEnvironmentalInformationandDataCenter.1977.AlaskaRegionalProfiles-YukonRegion.Anchorage,AK.346pp.ArcticEnvironmentalInformationandDataCenter.1974.AlaskaRegionalProfiles-Southcentra1Region.Anchorage,AK.255pp.Arneson,P.1984.NongameBiologist,personalcommunication.AlaskaDept.'ofFishandGame,Anchorage,AK.BechtelCivilandMinerals,.Inc.1983.ChakachamnaHydroelectricProjectInterimFeasibilityAssessmentRep~rt.PreparedfortheAlaskaPowerAuthority.Bell,M.1981.FisheriesHandbookofEngineeringRequirementsandBiologicalCriteria.Preparedforu.S.ArmyCOE,PortlandDistrict.u.S.Army1973(Revised1980.J453410/1084082010-2 ]C]r'"IJJc1JBell,M.1984.personalcommunication,PrivateConsultant,Mukilteo,"Washington.Bentz,Jr.,R.1983.InventoryandCatalogingoftheSportFishandSportFishWatersinUpperCookInlet.AlaskaDepartmentofFishandGame,SportFishDivision.Vol.24July1,1982-June30,1983.FederalAidinFishRestorationandAnadromousFishStudies.Buklis,L.S.1981.YukonandTananaRiverFallChumSalmonTaggingStudy.1976-1980.AlaskaDept.Fishand,Game,Info.LeafletNo.194.Juneau,AK.DarbyshireandAssociates.1981.SocioeconomicImpactStudyofResourceDevelopmentintheTyonek/BelugaCoalarea.Anchorage,Alaska.Elliott,C.L.1984.WildlifeFoodHabitsandHabitatUseonRevegetatedStripmineLand1nAlaska.Unpub.PhD.Diss.,Univ.ofAlaska,Fairbanks.178pp.EbascoServicesInc.1982.BrowneHydroelectricAlternativefortheRailbeltRegionofAlaska,VolumeXV.Faro,J.1984.AreaBiologist,personalcommunication.AlaskaDept.ofFishandGame,Soldotna,AK.FederalEnergyRegulatoryCommission.1984.SusitnaHydroelectricProjectFERCNo.7ll4-Alaska.DraftEnvironmentalImpactStatement.Guinn,C.1984.personalcommunication.AlaskaDepartmentofNaturalResources,Fairbanks,Alaska.Hartell,P.1984.personalcommunication.NationalParkService,LakeClarkNationalPark,Anchorage,Alaska.453410/1084082010-3 lClJ:1InternationalConferenceofBuildingOfficials.1980.PlanReviewManual.Whittier,California,269p.Jennings,L.1984.PersonalCommunication.AlaskaDept.ofFishandGame,Fairbanks,AK.Johnson,D.1984.PersonalCommunication.AlaskaDept.ofFishandGame,DeltaJunction,AK.ClMartin,G.Alaska.No.19.1983.UseofNaturalResourcesBytheResidentsofDotLake",AlaskaDept.ofFishandGameSubsistenceDiv.,Tech.Paper105pp.]J]1I.J1JMcHenry,T.1984.Personalcommunication.AlaskaDept.ofFishandGame.Seward,AK.Money,D.1984.PersonalCommunicationU.S.FishandWildlifeService,Anchorage,AK.Miller,S.andD.C.McAllister.1982.SusitnaHydroelectricProject.PhaseI.FinalReport.BigGameStudies,Vol.VI,BlackBearandBrownBearAlaskaDept.ofFishandGame,Anchorage.Miller,S.1983.SusitnaHydroelectricProject.PhaseII.ProgressReport,BigGameStudies,Vol.VI.BlackBearandBrownBear.AlaskaDept.ofFishandGame,Anchorage.Mills,M.1983.Statewideharvestsurvey1982data.AlaskaDept.FishandGame,DivisionofSportfish.Vol.24,July1,1982-June30,1983.FederalAidinFishRestorationandAnadromousFishStudies.453410/1084082010-4 ]Nichols,L.1984.Personalcommunication.AlaskaDept.ofFishandGame,CoopersLanding,AK.Pitcher,K.1984.Personalcommunication.AlaskaDept.ofFishandGame,Anchorage,AK.Post,A.andL.R.Mayo.1971.GlacierDammedLakesandOutburstFloodsin,iAlaska.Robus,M..1984.PersonalCommunication.AlaskaDept.ofFishandGame,Fairbanks,AK.Scudder.1977.BigDamsandLocalDevelopment1nAfrica.CaliforniaInstituteofTechnology,DivisionofHumanitiesandSocialSciences:Pasadena.July.problemsandEnvironmentalEffects"SymposiumHeldinKnoxville,Tennessee.May3-7,1971.]JScudder.1971•.Summary:Resettlement.From"Man-MadeLakes:Their]ISchneider,k.1984.Personalcommunication.AlaskaDept.ofFishandGame,Anchorage,AK.Spraker,T.H.1984.Personalcommunication.AlaskaDept.ofFishandGame,Soldotna,AK.Steen,N.1984.Personalcommunication.AlaskaDept.ofFishandGame,.JPalmer,AK.u.S.ArmyCorpsofEngineers.1981.NationalHydroelectricPower~tudyRegionalReport:Vol.XXIII.453410/1084082010-5 'lJU.S.BureauoftheCensus.1980.1980CensusofPopulation.CharacteristicsofthePopulation,NumberofInhabitants,Alaska.PC80-l-A3.u.s.DepartmentofCommerce.u.s.BureauofReclamation.1965.Open-fileReports.LocatedattheU.S.DepartmentofEnergy,AlaskaPowerAdministration,Juneau,Alaska.u.s.BureauofReclamation.1977.DesignofSmallDams.U.S.GovernmentPrintingOffice,Washington1977.u.s.FederalPowerCommission.1976.The1976AlaskaPowerSurveyVolume1.WashingtonD.C.u.s.GeologicalSurvey.1961.PreliminaryRepo.rtontheWaterpowerResourcesoftheSnowRiver,NellieJuanLake,andLostLake,KenaiPeninsula,Alaska.Watsjold,D.1984.Personalcommunication.AlaskaDepartmentofFishandGame,Anchorage,AK.]Wilson,J.1984.Personalcommunication.NationalForest,Seward,Alaska.u.s.ForestService,Chugach1J_JJWoodward-ClydeConsultants,Inc.1983.SHP-FinalReportonSeismicStudiesforSHP.March1983.453410/1084082010-6 TABLES r , L.--1 ---'--------..;'-......--J '-------'<-----! TABLE 1 ENGINEERING ASSESSMENT ALTERNATIVES VS.SUSITNA ++ 0 7+2+7+10+ 35+_7+---5 Project Feature 1.Access 2.River Diversion 3.Camp 4.On-Site Roads 5.Impervious Borrow 6.Pervious Borrow 7.Rock Borrow 8.Relocations 9.Transmission 10.Dam 11.Foundation 12.Disposal 13.Powerhouse 14.Spillway 15.Reservoir 16.Schedule 17.Fish Passage Facility Individual Net Rating Overall Rating Browne + + + + + + + + + + + + Johnson + + + + o + + + + + Alternatives Keetna Snow ++ ++ + ++ + + + ++ ++ + ++ -- ++ ++ ++ Proposed Project Chaka-Devil chamna Watana Ca~on + ++ + +++ ++ + ++ +++ +++ ++ + ++ ++ + + ++ + ++ + ++ + ++ + ++ 0 0 9+12+ 12+ 24+=12+ 2 LEGEND:+No foreseeable problems;condition better than normal;acceptable conditions Foreseeable problems or need;entails extensive work or cost o Not applicable to scheme Higher rating signifies preference from engineering standpoint. 453410/TBL 840.820 '--~'------"'-------'~---'~~~ TABLE 2 COMP ARrSON OF LAND AREA IMPACTEDA,B Acres Impacted by Acres Impacted Non-Susitna Hydroelectric Alternative Sites by Proposed Project Project Chaka-Devil , Feature JohnsonC BrowneD Keetna E Snow F chamnaG WatanaH Canyon- Reservoir 94,500 12,500 5,500 3,200 -36,000 7,900 Transmission 1,640 50 130 1,050 3,150 10,600 -K Lines J Camp 'Site 100 100 100 100 200 160 90 Borrow Areas 500 20 150 40 10 4,000 400 Access Roads 70 30 90 20 80 630 400 Highway 800 200 Railroad -190 ----70 Other 550 -- --210 100 Total 98,160 13,090 5,970 4,110 3,440 51,900 8,960 Overall Totals 124,770 60,860 Note:Figures represent estimated amount (acres)of surface area lost or disturbed by activities associated with the non-Susitna hydroelectric alternatives and the Proposed Project. 453410/TBL 840820 I]'J'1:r].1FootnotestoTable2A:Theareaestimatesdonotincludeacreagescoveredbyphysicalstructuressuchasspillways,powerhouses,dams,orsaddledams;nordoesitincludeestimatesfortherelocationofanydwellingsorcommunitiesinundatedbyaparticularproject.Unlessotherwisenoted,theamountofareadisturbedbyrights-of-way,borrowareas,andareainundatedbyeachimpoundmentarebasedonestimatesprovidedinthisreport.B:Acreageestimateshavebeenroundedtonearest10acres.c:Highwayestimatebasedonprojectedrelocationof23milesofhighwaywitha200footright-of-way.Transmissionlineareaestimatebasedontwin138KVtransmissionl~nes135mileslongwitha100footright-of-way.Borrowareaestimatesbasedonanimperviousborrowsitemeasuring5,500x4,000feetandarockborrowsitemeasuring500x500feet.Accessroadareabasedonestimatedneedfor20milesofroad30feetwide."Other"includes8acresforanewhighwaymaintenancestationand23milesofrelocatedpipelinewitha100footright-of-way.D:Highwayestimateisbasedonprojectedrelocationof8.5milesofhighwaywitha200footright-of-way.Transmissionlineareaestimatebasedonapairof138kilovolt(KV)transmissionlines4.5mileslongwitha100footright-of-way.Accessroadareabasedonestimatedneedfor10milesofroad30feetwide.Relocatedrailroadestimatebasedon16milesofrailroadwitha100footright-of-way.Borrowareaestimatesbasedonanimperviousborrowsitemeasuring1000x1000feetandarockborrowsitemeasuring500x500feet.E.Transmissionlineareaestimatebasedon~,p~nrof138KVtransmissionlines11mileslongwitha100footright-of-way.453410/TBL840820 '1J]J1IIJFootnotestoTable2(Cont'd)Borrowareaestimatedbasedonimperviousborrowsitesmeasuring2,000x1,000feet,4,000x800feet,and2,000x750feet,andarockborrowsitemeasuring500x500feet.Accessroadareabasedonestimatedneedfor25milesofroad30feetwide.F:Transmissionlineareaestimatebasedon:(1)one115KVline30mileslongwitha100footright-of-way,and(2)one115KVline60mileslongwitha100footright-of-way.Borrowareaestimatesbasedonanimperviousborrowsitemeasuring1,100x1,500feetandarockborrowsitemeasuring500x500feet.Accessroadareabasedonestimatedneedfor4milesofroad30feetwide.G:Transmissionlineareaestimatebasedontwin230KVtransmissionlines130mileslongwitha200footright-of-way.Borrowareaestimated'basedon2rockborrowareas,eachmeasuring500x500feet.Accessroadareabasedonestimatedneedfor24milesofroad30feetwide.Campareabasedonlandneededfortwocamps.H:AreaestimatesgiveninthissectionarefromtherevisedLicenseApplicationtablesappendedtoResponsetoAgencyComment1.370(Reference1.370.2),submittedFebruary15,1984.Transmissionlineestimatesareforjointdamoperationforcorridorsfrom:HealytoWillow(3437ac),WatanatoGoldCreek(1538ac),HealytoFairbanks(3527ac),andwillowtoCookInlet(2056ac).'Other'includesestimatesfortheareaimpactedbypermanentvillageandairstrip.I:AreaestimatesgiveninthissectionarefromtherevisedLicenseApplicationtablesappendedtoResponsetoAgencyComment1.370(Reference1.370.2),submittedFebruary15,1984.453410/TBL840820 FootnotestoTable2(-Con't)J.Arearepresentsaworst-caseestimateofareaimpactedS1nceonlyforestandtallshrubtypeswouldrequiremajorclearing.Valuesdonotincludeareasthatwouldbeaffectedbyexpansionofexistingtransmissionlines.K.TransmissionlineareaestimatesfortheDevilCanyonprojectareincludedinacreagegivenforWatana(seefootnoteH).1:J1I~JIJ1IJ1.J]J453410/TBL1840820.J 1J1J]jJ1JTABLE31982SUMMARYESTIMATEDCHAKACHAMNASALMONESCAPEMENTBYWATERBODYANDDRAINAGEChakachamnaRiverDrainageMeArthurUpstreamDownstreamRiverSpeciesofDamSiteofDamsiteDrainageTotalSockeye41,3572,280.34,93378,570Chinook2,1072,107Pink19,77719,777Chum2929Coho4,7294,729OverallTotal41,3572,28061,575105,212Source:Bechtel1983453410/TBL840820 IMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTSheet1of2ALTERNATIVESSUSITNASNOWCHAKACHAMNATOTALNON-SUSITNAHYDRO•Seward,EasternPeninsulaofKenaiPeninsulaBorough.•Tyonekandsurroundingsmallcommunities.•TrapperCreek,Cantwell,andTalkeetna.!rCreekwouId•Peakconstructionin-migrationwouldbe900persons.•Peakconstructionin-migrationwouldbe•Theprojectwouldincreasepopulationsinanumberof•Communitiesreceivingmajorin-migrationwouldapproximately2,000persons.smallcommunities;insomecases,theimpactswouldincludeTrapperCreek,Cantwell,andTalkeetnabesubstantial.PopulationimpactsarelikelytobeImpactsareexpectedtopeakin1990.underestimatedbecauseoflittleornoconsiderationtoconstructionofancillaryfacilities(roads,railroad,transmissionlines)inaddition,togreaterpopulationsduetoincreasedaccess..idents'qualityof•Rapidgrowthimpactswouldalterresidents'qualityof•TheprojectwouldinterferewiththeNativecultureand•ImpactswouldbesimilartoSusitnaanddispersed•TherurallifestyleofTrapperCreek,Cantwell,and(tolifeandtheruralnatureofthearea.subsistenceactivitiesofTyonekandsurroundingamongalargernumberofcommunities.Communitiesalesserdegree)Talkeetnawouldbechanged.Cantwellcommunityresidents.suchasDotLakeandTyonekwouIdexperiencemayexperienceincreasedculturalconflict.potentiallysevereculturalandsubsistenceinterference.Jnitiesfor•SomeSewardresidentsmaybehiredleadingtoa•Commercialoperationswouldexpandanddiversify.•Existingcommercialestablishmentsinmost•Somelocalresidentswouldgainemployment,resultingnandtouristreductioninSeward'shighumployment.communitieswouldexperienceanincreaseinbusinessinminorreductionofunemployment.Sometourist,andsomewouldexpand.Newopportunitiesrelatedtoconstruction,andservice-relatedindustrieswouIdbetourismandrecreationwouldbecreatedinsomeareascreatedorexpanded.Someguidingbusinesseswouldandlocalresidentsfromafew.communitiesmayfindbedisplaced.Periodsbetweenpeakemploymentcouldproject-relatedemployment.increaseunemployment.romtheSusitna•Upto300housingunits(permanentortemporary)•Considerablehousingdevelopmentwouldberequired• Asmallnumberofcommunitieswouldrequire•HousingdemandwouldrequireexpansioninTalkeetna,wouldbeneeded.toaccommodatethein-migrationof2,000personsconsiderablehousingdevelopmentforpermanentTrapperCreek,Cantwell,andunincorporatedMat-Susincelit'ble'ernovacanthousingiscurrentlyavailable.and/ortemporaryproject-relate'din-migrants.Boroughareas.Demandwouldbelikelytoexceedsupplyintheshort-term.romtheSusitna•Sewer,waterandothercommunityserviceswouldbe•Sewer,water,fire,policeandhealthfacilitieswould•Mostcommunitieswouldrequireanexpansionof•ServiceswouldrequireexpansioninTalkeetna,Trapperneeded.Schoolsarelikelytobeabletoabsorbnewhavetobeadded.TheTyonekschoolwouldhavetocommunityservicesincludingsewerandwater,policeCreek,Cantwell,andunincorporatedMat-SuBoroughstudentsbutmoreteacherswouldbeneeded.beexpandedby50%.andfire,healthfacilitiesandpersonnel.areas.Mostnotableneedswouldbeinschools,firedepartments,policedepartmentsandhealthservices.ftheMat-Su•Planning,financing,andconstructioncostsforSeward•Constructionandplanningofserviceswouldbe•Fundingforplanningandconstructionofexpanded•Responsibilityforcommunityserviceexpansionwouldwouldbefundedbythecity.fundedbytheKenaiPeninsulaBorough.communityserviceswouldberequiredfrommanybewiththetowns,borough,orthestate.townsandcitieswhilethestatewouldincurcosts-foranumberofunincorpoaratedplaces.accessthesite•Additionalroadswouldbeneededtoaccessthesite•Additionalroadswouldbeneededtoaccessthesite• Anumberofnewroadswouldberequiredtoaccess•Alltransportationmodesandroutesleadingtothe~aseontheseandandtrafficvolumewouldincrease.andtrafficvolumeswouldlikelyincreaseontheseandthe5hydrosites.Additionally,theinundationofprojectareawouldbeusedmoreheavily.Onlytheothernearbyroads.milesofexistinghighway,railroad,pipelineandhighwayjunctionatCantwellthesiteaccessroadrights-of-waywouldrequireconstructionofnewjunctionwiththeDenaliHighway,andtherailaccessroutesconcurrentwithproposedproject construction.junctionandthemainraillinecouldbecomeconjested.Generallytrafficvolumeswouldincreaseonallroadsinandaroundimpactedcommunities,severalroadswouldlikelyreachcapacity.Table4COMPARISONSOFSOCIOECONOMICRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Table4-COMPARISONSOFSOCIOECONOMICRESOURCESAND.IMPACTSAMONG~A LSUBJECTJOHNSONBROWNEKEETNA1.COMMUNITIESANDAREASAFFECTED•Tok,Tanacross,DotLake,"TheLivingWord"atDryHealy,andNenana.•TalkeetnaandTrapperCreek.•Seward,Ea:CreekandDeltaJunction.•Duringthepeakconstructionperiod1,300persons•Peakconstructionin-migrationwouldtotal660•In-migrationtoTalkeetnaandTrapperCreekwould•Peakconstrwouldin-migratetothearea.persons.Constructionworkforcesontheroadsandtotal880persons.railwaywouldaddsubstantiallytoin-migrationand2.POPULATIONcompoundotherimpactsofBrowneconstruction.• Adecreaseintherural,undevelopednatureofthearea•Theprojectwouldinterferewithculturaland•Rapidgrowthimpactswouldalterresidents'qualityof•RapidgroW1mayoccur.withchangesinscenicquality.TheNativesubsistenceactivitiesofNenanaresidents.lifeandtheruralnatureofthearea.lifeandthe3.INSTITUTIONAL/QUALITYOFLIFEcommunitiesofTanacrossandDotLakemayexperienceculturalconflictsandsubsistenceinterference.•Existingcommercialoperationsmightexpandand•Commercialoperationsmayhaveincreasedbusinessin•Increasedaccesswouldcreateopportunitiesfor•SomeSewarothersopen.CommercialexpansionandrecreationlocalcommunitiesandFairbanks.commercialdevelopmentofrecreationandtouristreductioniropportunitiesattheimpoundmentmayencouragefacilities.4.ECONOMY/EMPLOYMENTtourism.Somelocalresidentsmayfillsupportjobs.•About400householdswouldrequiretemporaryor•Considerablehousingdevelopmentwouldbeneededto•SubstantialimpactssimilartothosefromtheSusitna•Upto300h5.HOUSINGpermanenthousing;mostin-migrantswouldsettleinaccommodate300newhouseholds.Projectwouldoccur.wouldbeneTokandDeltaJunction.•Communityserviceswouldhavetobeexpanded•Schools,sewerandwater,policeandfire,andhealth•SubstantialimpactssimilartothosefromtheSusitna•Sewer,watel6.COMMUNITYSERVICESconsiderably.facilitiesandfull-timepersonnelwouldneedtobeProjectwouldoccur.needed.Schladded.studentsbut•DeltaJunctionwouldfinancethecostsofcommunity•Planning,financingandconstructionofadded•ImprovementswouldbeatexpenseoftheMat-Su•Planning,fin7.FISCALSTATUSexpansionneeds.ThestatewouldfinancethecostsofcommunityservicesinNenanawouldbefundedbytheBorough.wouldbefUicommunityexpansionforTok.town;inHealysuchfundingwouldbebythestate.•Theimpoundmentwouldinundateportionsofthe•10milesoftheParksHighway,AlaskaRailroad,and•Additionalroadswouldbeneededtoaccessthesite•AdditionalrcAlaskaHighway,ahighwaymaintenancestation,transmissionlineright-of-waywouldbeinundated.andtrafficvolumeswouldlikelyincreaseontheseandandtrafficvc3gravelpits,2streamgagingstations,apipeline,othernearbyroad.8.TRANSPORTATIONtelephoneline,lodge,andtwocommunities(DotLakeand"TheLivingWord"atDryCreek). IMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTSheet2of2ALTERNATIVE SSNOWCHAKACHAMNATOTALNON-SUSITNAHYDROSUSITNA•Constructionworkforce=200•Peakconstructionworkforce=400•Peakconstructionworkforcein1990=3,500Constructionperiod=4yearsConstructionperiod=5yearsstingpopulation•Duetothisproject'sconcurrencewithBrowne's•Tyonekwouldexperiencesignificantimpactsfromthe•Populationimpactsusedinthiscomparisonarethoseconstruction(200milesaway)populationimpactsin-migratingconstructionpopulation.entitled"Applicant(Rev,)"intheDEIS.InMarchwouldincrease, shortagesofsuppliesexacerbated,and•Permitstoconstructroadstothesitemaybedifficult1984theapplicantsubmittedrevisedprojectionsthatsupplyroutes(highwaysandrailroads)mayhavedecreasedtheimpactsonTalkeetnabutincreaseddifficultieswithcarryingcapacity.toobtainfromtheTyonekNativeCorporation.impactsonHealyandMcKinleyPark.I!Table4COMPARISONSOFSOCIOECONOMICRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Table4-COMPARISONSOFSOCIOECONOMICRESOURCESANDIMPACTSAMONGNALSUBJECTJOHNSONBROWNEKEETNA•Peakconstructionworkforce=300•Peakconstructionworkforce=200•Constructionworkforce=200•ConstructiorConstructionperiod=7yearsConstructionperiod=4yearsConstructionperiod=4yearsConstructior9.ASSUMPTIONSItisassumedthatintheworsecaseonly75%oftheconstructionworkforcewouldcommutefromFairbanks.•Duringconstructionifthereisnocampon-sitehousing,•Browne'slocationbetweenHealyandNenanawould•In-migrationwouldalmostdoubleexistingpopulation•Duetothis1=thensevereimpactswouldoccurintheareabetweenleadtoconstructionandoperationimpactsmainlyinsoimpactswouldbesignificant.constructionTokandDeltaJunction.thosetowns.wouldincrec10.COMMENTS•Themostseriousimpactswouldbetheinundationof•Duetotheproject'sconcurrencewithKeetnasupplyroutetwocommunitiesDotLake(population:67)andliTheconstruction(200milesaway)populationimpactsmaydifficultiesVILivingWord"(population:200).beincreased;shortagesofsuppliesexacerbated,and• Alodgemayalsobeinundated.supplyroutes(highwayandrailroads)mayhavedifficultywithcarryingcapacity.•TherapidgrowthimpactstoTokandDeltaJunctionwouldbeexaggeratedbyroadandpiperineworkforces. AMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTALTERNATIYESSUSITNASNOWCHAKACHAMNATOTALNON-SUS-ITNAHYDROelandused•Accessduetonewprojectroadsandthereservoir•The-ruggedterrainsurroundingthesiteisused•Accesstorecreationlandswouldbegreatlyincreased•IntheprojectareawheredispersedrecreationistheItionpurposes.wouldincreasebackcountryuse,impactsonvegetationprimarilyforrecreationincludinghunting.Increasedleadingtoincreasedpressureonvegetation,wildlifeprimarylanduseincreasedincreasedpressuresfromdordisposalbyandwildliferesources,andaffectthenaturalsettingofaccesswithroadsandatransmissionlinecorridorresources,andthequalityoftheremotenaturalpossibleresidential,commercial,andnaturalresourcesandremotetheforestlands,particularlyinareasclosesttothewouldsignificantlyincreasesuchusesofthearea.setting.Comparedtorecreationlands,theeffectsondevelopmentandrecreationalactivitiescoulddisturb:>ject'saccesshighway.Approximately2,600acresoflandwouldbe•Sincetheprojectcallsforalaketap,anegligiblesettlementandagriculturallan~swouldbesignificant.vegetationandwildlifeandfisheriesresources.)uldsignificantlyremovedfromexistinguses.Also,acombinedtotalof115;640acreswouldbelost'asingtraffic,amountoflandwouldberequiredandoveralllandusefromcurrentuses.•Approximately36,000acresand6structureswoulddbyreducingimpactswouldbeminimal.beinundatedwithWatana;7,900acreswithDeviling.Canyon.~cresfromtheir•TheconstructioncampsfortheproposeddamsandItfromthedamthetemporaryvillageandairstripwouldcoverstateownership.approximately425acres.Idimpoundment•ThelandatthesiteisfederallandwithintheChugach•The.Iandat thesiteisstateland.Landtotheeast•Landownershipiscomplexandvariedatmanysites•Landsatthedamandimpoundmentsitesareowned,ownthelandtoNationalForest.However,nearbysitesthroughwhichthroughwhichaccessroadsandtheutilitylineswouldparticularlywhereaccessroutesandtransmissionbythestateandvariousNativeentitiesincludingtheandutilitiesthetransmissionlinewouldrunareinprivaterunincludeNative,boroughandstatelands.corridorsoccur.DifficultiescouldresultwhenCookInletRegionNativeCorporation.ownership.negotiatingpurchasesoreasementsacrossprivateland.::Isand•Nationalforestareusuallymanagedformultipleuse•Duetothemultipleownershipoflandsthroughwhich•Wheremultipleownershipexists,particularlyalong•SincelandmanagementplansfortheprojectareacallIdsmaycreateallowingforsomedevelopmentwhichcouldincludetheaccessroadsandtransmissionlinecorridorwouldaccessandtransmissionlineroutes,conflictsmayoccurformultipleuseandactualmanagementisessentiallyIds.constructionsimilartothatoftheproject.run,conflictswithmanagementplansmayoccur.withexistingorintendedmanagementplans.passive,theprojectwouldnotappeartopresem.conflicts.Table5COMPARISONSOFLANDUSEANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Table5-COMPARISONSOFLANDUSEANDIMPACTSAMONGNON-SUSrSUBJECT,ALJOHNSONBROWNEKEETNAI•Thelandinandaroundthesiteisprimarilyforest,•Thelandat thesiteisbeingdisposedbythestateto•Thelandinandaroundthesiteisstatelandused•Accessdue'wildlifehabitat,andrecreationlandwithisolatedprivateindividualsforsettlementandagriculturaluses.primarilyforhuntinga'ndotherrecreationpurposes.wouldincresettlements,mineralandgravelextractionareas,andSignificantimpactswouldoccurfromincreasedLandstothewestaresettlementlandsfordisposalbyandwildlifetransportationandutilitycorridors.Theseuseswoulddevelopmentpressures,increasedcompetitionforthestateashomesteads,subdivisions,andremotetheforestIebegreatlyimpactedbytheinundationofrecreationandwildliferesourcesanddisturbanceofparcels.Impactsresultingfromtheproject'saccesshighway.AI1.LANDUSEapprOximately84,000acresoflandandbyaccessintothenatural,remotesettingduetonewaccessbyroadandtransmissionlinecorridorwouldsignificantlyremovedfrcnewareasopenedbyprojectroads,thetransmissionprojectroadsandutilitycorridors.impactthesesettlementareasbyincreasingtraffic,linecorridor,andreroutingofthehighwayandpipeline.•PortionsoftheGeorgeParksHighwayandAlaskarecreationpressuresonstatelands,andbyreducing•PortionsoftheAlaskaHighwayandanoilpipeline,aRailroadwouldbeinundatedalongwithapproximatelythequalityoftheremotenaturalsetting.highwaymaintenancestation,3gravelpits,2stream5,000acresoftheHealyAgriculturalSubdivision,•Theinundationwouldremove4,800acresfromtheirgagingstations,atelephonelineand2communities(Dototherprivatetractsandatleastoneminingclaim.presentuses.Fewimp~ctswouldresultfromthedamLakeandanotheratDryCreek)wouldbeinundated.andimpoundmentsincethelandisinstateownership.•Landownershipatthesiteandthroughwhichaccess•Landinandaroundthesiteisownedprimarilyby•Thestateownsthelandat thedamandimpoundment•Thelandatwouldoccurincludesstateforestlands,Nativelands,privateindividualsandthestatewhichintendstosites.ThestateandprivateindividualsownthelandtoNationalFo2.LANDOWNERSHIPandprivatelandsacquiredfromstatelanddisposaltransfertheirlandstoprivateownershipthroughthewestthroughwhichprojectroadsandutilitiesthetransmiprograms.disposedprograms.wouldrun.ownership.,•Theinundationcouldgreatlyaffectthemanagement•Sincethelandhasbeen,orisbeingdisposedof,bythe•Thelocationoftheprojectaccessroadsand•Nationalfor3.MANAGEMENTPLANSplansofthevariouslandowners.stateforprivateuse,projectusesmaybeinconflicttransmissioncorridordverdisposallandsmaycreateallowingforwiththoseofavarietyofprivateowners.conflictswithprivateusesofthoselands.constructiol Table6-COMPARISONSOFCULTURALRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTALTERNATIVESSUBJECTTOTALSUSITNAJOHNSONBROWNEKEETNASNOWCHAKACHAMNANON-SUSITNAHYDRO1.·NUMBEROF•None•50+•None•Presentbutnot•None•50+.250+KNOWNquantified.CULTURALRESOURCESINAREA2.LIKELIHOODOF•Verylikely;numbers•Verylikely;not•Verylikely;not•Verylikely;not•Possible,butfewerthan•Likelytoexceedthose•Possible,butnotlikely.PREVIOUSLYmayexceedSusitnaquantifiableatthisquantifiableatthisquantifiableatthisatothersites.knownattheSusitnaUNKNOWNProjectduetosizeoftime.time;probablyfewertime;probablyfewersite.RESOURCESprojectandlocationthanSusitna.thanSusitna.BEINGnearamajorriverDISCOVEREDcorridor.3.SCOPEOF•Verylarge-scalefield•Large-scalefield•Large-scalefield•Large-scalefield•Moderate-scalefield•Majorundertaking•Onlysmall-scaleNEEDEDstudiesnecessary.studiesnecessary.studiesnecessary.studiesnecessary.studiesnecessary.necessary,exceedingadditionalstudiesADDITIONALstudiesdonefortheneeded.IDENTIFICATIONSusitnaProject.STUDIES•4.SCOPEOF•Likelytoexceedthat•Likelytobelessthan•Likelytobelessthan•Likelytobelessthan•Likelytobelimited•Mayexceedthat•Large-scaledataNECESSARYrequiredforthethatrequiredforthethatrequiredforthethatrequiredfortheandmuchlessthanIrequiredfortheprogramnecessary.MITIGATIONSusitnaProject.SusitnaProject.SusitnaProject.SusitnaProject.othersites.SusitnaProject.Table6COMPARISONSOFCULTURALRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT PACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTALTERNATIVESSNOWCHAKACHAMNATOTALNON-SUSITNAHYDROSUSITNA!finestwhiteInofwhichisrboats.eranditsificantamountsateRecreation•ProjectsitelocatedwithinChugachNationalForest.•Areausedforhunting,camping,fishing,andwildernesshiking.•ForestservicerecreationalcabinlocatedonParadiseLakewithinimpoundmentzone.•SewardHighwayandAlaskaRailroadpasswithin3milesofdamsite.•ProjectsitelocatedwithinMerrillPass- amajoraircorridortoLakeClarkNationalPark.•LakeChakachamnausedasstagingareaforaccesstosurroundingareaforhiking,fishing,andhunting.•HeavyfishinguseinMcArthurandChakachatnaRivers.•WaterfowlhuntinginTradingBayStateGameRefuge.•Heavyboatinguseonthreerivers.•Projectsincloseproximitytothreemajorhighways,railroad,andamajoraircorridor.•Tworivers,onestream,andthreerecreationareaswithinprojectareasarerecommendedforStateprotection.•Projectscoverlargeareasusedforhuntinganddispersedrecreationalactivities.•OneprojectwithinaNationalForestandtwonearNationalParks.~•Largeareawithlowlevelofdispersedrecreationaluse(duetoremoteness).•ModerateamountsofboatingusebelowDevilCanyonandaboveVeeCanyon.•LimitedwhitewaterboatingofDevilandVeeCanyonRapids•DevilCanyonRapidsconsideredworldclasswhitewaterresource.•Lowlevelsoffishinguseinareastreamsandlakes•Scatteredcabinsalongrivercorridorusedforhuntingandtrapping.•Areareceivesmoderateamountofuseforhunting.•Twolodgeswithinprojectareausedforhuntingandfishing.Jpstreamofdam.•LossoffishingopportunitiesinlowerParadiseLake;noreplacementbyimpoundmentexpecteddueto~onewouldbeturbidwaters.irmayoccur.•Lossof46,00acresofbiggamehuntingarea.•Increaseinhuntingandfishingpressureduetonewaccesstoremotearea.•Existingfisheryintheimpoundmentzonewouldbelost;somereplacementmaybepossible;turbidreservoirsmayreduceopportunities.•Newaccesscoulddecreasefisheryresourcesbyallowingoverfishingofareastreamsandlakes.•DevilCanyonRapidsandVeeCanyonRapids•inundated-significantwhitewaterboatingopportunities.•Lossofpotentialriverboatingopportunities.~Newopportunitiespossibleonreservoir;butlimitedduetowind,turbidwaters,anddrawdowns.Lossoflandusedfordispersedrecreationalactivities.•Increasedinrecreationdemandduetonewaccessandinfluxofpeopleduringconstructionandoperation.•Newaccesstothreeremoteareasincreasinghuntingpressure.•Fishingpatternsalteredatallsites.Somereplacementmaybepossiblebynewimpoundment;however,turbidreservoirswouldreducetheopportunities.•Significantfishingareaslost.•Notablerapidslostonfourrivers.Significantlossofwhitewaterboatingononeriver.•Impactstoboatingopportunitiesonfiverjvers,significantimpactstoboatingonthreerivers.•Lossoflargeareasoflandusedforland-basedrecreation.•Inundationoftworiversandonestreamrecommendedforstateprotectionandnumeroussmallsitesrecommendedforstaterecreation.•ImpactstosightseeingfrolTlthreemajortravelroads,railroad,twoNationalParks,andoneNationalForest.•Substantialincreaseinrecreationdemandduetofiveprojectsindifferentareasofthestate;project-inducedpopulationincreasesandproximityofsitestomajortravelroutes.•IncreaseinhuntinginTradingBay.StateGameRefuge.•Lossofover110,000acresofhuntingland,someheavilyused.•Increaseincompetitionbyhuntersduetoaccesstoremoteareas.•Fishingpatternsalteredduetochangesinexistingflowpatternsanddiversions.•Lossofboatingpoten/tialinChakachatnaRiver.•IncreasedusetoLakeClarkNationalParkbynewaccessintowilderness.•Increaseduseofareaduetoincreaseinproject-inducedpopulation.•3,200acresofmoderatelyusedmoosehuntingareainundated.•Increaseddemandonhuntingandfishingresourcesduetoincreaseinaccesstoremotearea.•LossofforestservicecabinlocatedonParadiseLake.•Newboatingopportunitespossibleonreservoir,butlimitedduetoturbidwaters,windanddrawdowns.•IntrusiononwildernesshikingexperienceinChugachNationalForest.•ImpactstoviewsfromSewardHighwayandAlaskaRailroad.•Potentialtoincreaseuseoftheareaviaincreasedaccess.ltingareatodownstreamoftheareaviaIreservoir,butidrawdowns.tedanddispersedingresourcesIrea.ndprivateIterboatingisrecommendedNhichisalsonproject-inducedTable7COMPARISONSOF RECREATIONRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Table7 -COMPARISONOFRECREATIONRESOURSE$ANDIMPACTSAMONGNOSUBJECTALJOHNSONBROWNEKEETNA,•TananaRiverheavilyusedforprivateandcommercial•NenanaRiverheavilyusedforrivertraveland•TalkeetnaRiverconsideredoneofthefinestwhite•Projectsiteboating.moderatelyusedforrecreationalboatingandfishing.waterraftingareasinState.•Areausedf•CharterboatservicelocatedatDotLake.•ParksHighwayandAlaskaRailroadaremajortourist•TalkeetnaRiverusedheavily(aportionofwhichiswilderness•TananaRiverproposedbytheStateasamultiple-useroutes.withinimpoundmentzone)bycharterboats.•Forestservi,river.•Developedrecreationfacilitieswithinimpounament•Heavyfishingoccursin'TalkeetnaRiveranditsLakewithir•TananaRiversupportsmoderatelevelofsportfishing.areaincludetrails,restarea,andscenicoverlookstributaries.•SewardHigRECREATIONRESOURCES•Intensivefishingoccursinnumberofsmalllakesin•Moderatelevelsofhunting,fishing,andhikingoccur•TalkeetnaRivercorridclrreceivessignificantamountsmilesofdarinprojectarea.ofhikingandhuntingJse.projectarea.•Significantamountsofhuntinginprojectarea.•Impoundmentapproximately3milesfromDenali•TalkeetnaRiverrecommendedasaStateRecreationNationalParkboundary.River.'•Numerousmultiple-usetrailsthroughoutprojectarea.•Threeareaswithinprojectareaarerecommendedas•AlaskaHighway(aportionofwhichwithinStaterecreationsitesandreserve.impoundmentzone)ismajortouristroute.•94,500acresoflandusedforbigandsmallgame12,500acresofmoderatelyusedhuntingareas,.5,500acresofheavilyusedmoosehuntingarea•3,200acreshunting,inundated.inundated.inundated.inundated.•Increasedemandonhuntingandfishingresourcesdue•FishingopportunitieslostinNenanaRiver.•Increaseddemandonhuntingandfishingresources•Increasedd.toincreaseinaccesstoremoteareas.•Potentialnewopportunitiesintheimpoundmentforduetoincreaseinaccesstoaremotearea.toincrease•FishingopportunitieslostinTananaRiverandlakessubsistencefishingbutnotrecreationalfishingdueto•FishingopportunitiesI~stforsalmonupstreamofdam.•Lossoffishwithintheimpoundmentzone.turbidwater.Inoreplacerr•Existingfisheryintheimpoundmentzonewouldbeturbidwate•Potentialnewopportunitiesintheimpoundmentfor•Salmonabovethesitethatcontributetodownstreamlost;potentialreplacementbyreservoirmayoccur.subsistencefishingbutnotrecreationalfisheryduetofisheriesmaybelost.•Salmonabovethesitethatcontributetodownstream•Lossofforeturbidwater.•Popularintermediatelevelkayakingcourseinundated.fisheriesmaybelost.•Newboatin•Salmonabovethesitethatcontributetodownstream•LossoffreeflowingsectionofNenanaRiverwhichis•Damwouldblocksignificantwhitewaterboatinglimitedduefisheriesmaybelost.intensivelyusedforrivertravelbyallboaters.corridor.• Intrusionor•LossofTowerBluffrapidsandwhitewaterboating.•Limitedreservoirboatingopportunitiesavailabledue•Lossofexistingpopula~commercialandprivateNationalFaRECREATIONIMPACTS•Lossofpopularcommercialandprivateboatingtowind,turbidwater,andextensivedrawdowns.boatingopportunities.'•Impactsto,resourceandtransportationcorridorwithcharter•Lossoflandusedfordispersedrecreationalactivities.•Newboatingopportunitiespossibleonreservoir,butRailroad.boatsonTananaRiver.•Lossofrecommendedstaterecreationareas(Junelimitedduetowind,turbidwater,anddrawdowns.•Potentialto•Limitedreservoirboatingopportunitiesavailabledueaccess.towind,turbidwater,andextensivedrawdowns.Creek,BearCreekandKobeHill).•Lossoflandusedheavilyfortrail-relatedanddispersedrecreationalactivities.•Lossoflandusedfordispersedrecreationalactivities.•LossofrestareaonGeorgeParksHighway.•InundationofTalkeetnaRiverwhichisrecommended•TananaRiver,recommendedasstatemultiple-useriver•RelocationofpartsofGeorgeParksHighwayandasaStateRecreationRiver.willbeinundated.AlaskaRailroadeliminatingexistingviewsand•InundationofDisappointmentCreekwhichisalsoprovidingviewsofproject.•InundationofportionofAlaskaHighwayandlossofIncreaseinrecreationdemandduetolossofexistingrecommendedforprotection.relatedrecreationactivitiessuchascamping,sightseeing,andwildlifeviewing.facilities/areasandincreaseinproject-induced•Potentialtosubstantiallyincreaseuseoftheareaviapopulation.airandroadaccess.•Increaseincompetitionforexistingfacilitiesand•Increaseduseofareaduetoincreaseinproject-induceddemandforadditionalfacilitiesduetoprojectinducedpopulation.population. 'CTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTALTERNATIVESSNOWCHAKACHAMNA•TOTALNON-SUSITNAHYDROSUSITNA)fTalkeetnas.~creationRiver.tinelRockand•Veryhighscenicvalue.•ModeratevisualsensitivityduetoSewardHighwayandAlaskaRailroadpassingclosebyandrecreationaluseofthearea.•NotablescenicattractionsincludetheSnowRiverGorge,ParadiseLakes,andParadisePeak.•Highscenicvalue.•ModeratevisualsensitivityduetositebeingwithinMerrillPossaircorridor.•NotablescenicattractionsincludeChakachatnaRiverCanyon,ChakachamnaLake,andsurroundingmountains.•Threesiteslocatedinareasofhighscenicvalue,twositesinareasofmoderatetohighscenicvalue.•Twositeslocatedinareasofhighvisualsensitivityandthreesitesinareasofmoderatevisualsensitivity.•Projectsitesincludeanumberofnotablescenicattractions.Moderatetohighscenicvalue.•Moderatetolowvisualsensitivityduetolimitedrecreationalactivitiesinareasaccessedviaplane,orboat.•NotablescenicattractionsincludeDevilandVeecanyons,DeadmanandDevilCreekfalls,andBigandDeadmanlakes.•Projectfacilities,excepttransmissionlines,wouldonlybevisiblefromprojectaccessroad.Mudflatsandbeacherosionwouldbevisibletousersofreservoirs.•3,800acresoflandwouldbeinundatedinareasofmoderatescenicvalue.•Twodams(DevilCanyon-646foothighandWatana-385foothigh)wouldbevisibleinasceniccanyonareaandwouldcontrastwiththesurroundinglandscapesetting.•DevilandVeecanyonswouldbepartiallyinundated.•DeadmenCreekFallswouldbeinundated.•Constructionoffacilitiesinanareathatispredominantlywilderness,•Projectfacilitiesandtransmissionlineswouldbevisible•Viewsofprojectfacilitiesandreservoirswouldbetorecreationalusersandairtrafficinamajorairextensiveduetodisturbanceoffourmajortraveltrafficcorridor.routes.•102,000acresoflandwouldbeinundatedinareasofmoderatetohighscenicvalue.•Approximately280milesoftransmissioncorridorroutedinareaswithhighvisualsensitivity.•Significantvisualimpactswouldoccurduetorelocationofexistingtravelroutesandutilities.•Directandindirecteffectswouldoccurtoseveralareasofscenicvaluelocatedalongsceniccorridors.•Directandindirecteffectswouldoccurtoseveralstateandnationallysignificantareas.•Minoramountoferosionandmudflatsvisibletousers.•Someshorelineerosionandmudflatswouldbevisibletousers.•Projectfacilities,includingtransmissionlinesandthedam,wouldbevisiblefromSewardHighwayandAlaskaRailroad.•SnowRiverGorgewouldbeinundated.•VisualimpactswouldoccurinNationalForestWildernessAreas.•90milesoftransmissionlinewouldbeconstructedinhighlyscenicvalleys.•50milesoftransmissionlinewouldbeconstructedina310fd d'df'I"Id. dhighlyscenicareawherenolinescurrentlyexist.•ootamanassociateaCIItleswouInunatepartofascenicvalleythatispredominantlywilderness.•AsignificantreductioninflowthroughChakachatnaH'hi.Soh F k S VIIIdbRiverCanyon,woulddiminishthescenicappealofthe•,IgYscenicutornowaeywouearea.Inundated.Rockand)Ietolocalusers.wouldinundateInificant:entlanddisposal~reek,,wouldbe19TalkeetnaTable8COMPARISONSOFAESTHETICRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Tablea-COMPARISONSOFAESTHETICRESOURCESANDIMPACTSAMONGNONSUBJECT,A LJOHNSONBROWNEKEETNA•Moderatescenicvalue.•Highscenicvalue.•Moderatetohighscenic,value.•Veryhighsc•AlaskaHighwaycorridorrecommendedbystatefor•VeryhighvisualsensitivityduetopresenceofParks•ModeratevisualsensitivityduetouseofTalkeetna•Moderatevi!scenicprotection.Highway,AlaskaRailroad,riveruse,andproximitytoRivercorridorandrecentlanddisposals.AlaskaRailr•HighvisualsensitivityduetopresenceofAlaskaDenaliNationalPark.•TalkeetnaRiverpropos~dasaStateRecreationRiver.ofthearea.AESTHETICRESOURCESHighway inprojectarea.•SegmentsofParksHighwayrecommendedforscenic•Notablescerhighwaydesignation.•NotablescenicattractionsincludeSentine.1RockandGorge,Parae•NotablescenicattractionsincludeTowerBluffRapids.GraniteGeorge.•NotablescenicattractionsareKobeHill,astaterecommendedscenictrail,andnumerousoverlooksonParksHighway.•Projectfacilitiesanddamwouldbehighlyvisiblefrom•ProjectfacilitieswouldbehighlyvisiblefromDenali•Projectfacilitieswouldbevisibletosignificant•ProjectfacilAlaskaHighway.NationalPark,GeorgeParksHighway,andAlaskanumbersofrivercorridorusersandrecentlanddisposaldam,would•TransmissionlineswouldbevisiblefromhighwayandRailroad.ownersinthearea.AlaskaRailrotherviewsfromTananaValley.•TransmissionlineswouldbevisiblefromDenali•TransmissionlinewouldbevisiblealongTalkeetna•Minoramou•ShorelineerosioncouldbeextensiveduetoopennessNationalParkandNenanaValley.River.•90milesof'andsizeofreservoir.•ExtensivemudflatswouldbevisiblefromParks•Someslumpingandbeacherosionvisibletolocalusers.highlyscenilLargemudflatswouldbevisiblefromAlaskaHighwayHighwayandAlaskaRailroad.•415footdamandassociatedfacilitieswouldinundate•310footdalandtootherrecreationalusers.•Additionalvisualimpactscouldoccurduetorelocationpartofahighlyscenicvalley.partofasce•Icefoggingcouldreducevisibilityinvalley.ofexistingtransmissionline.•TalkeetnaRiverandDisappointmentCreek,•Highlysceni•210footdamandassociatedfacilitieswoulddominate•265footdamandassociatedfacilitieswoulddominaterecommendedasscenicrivercorridors,wouldbeinundated.thevalley'svisualcharacterandstronglycontrastwithinundated.thevalley'svisualcharacterandstronglycontrastwiththesurroundinglandsacpe.•SnowRiverthesurroundinglandscape.•NotablescenicattractionsofSentinelRockand•VisualimpalAESTHETICIMPACTS•Crestlengthofdamwhichis3,000feetwouldbeGraniteGorgewouldbeinundated.•CrestlengthofdamwouIdbe6,400feetandwouIdbehighlyvisible.Wilderness)highlyvisible.•ExtensivecutsduetorelocationofAlaskaHighwayCutsandfillsfromrelocationofParksHighwayandwouIdbevisible.AlaskaRailroadwouldbevisible.•AlaskahighwayhasbeenrecommendedforscenicPortionsofNenanaRiverhavebeenreommendedasaStateRecreationRiver.protection.•TananaRiverhasbeenrecommendedasamultiple-usePortionsofGeorgeParksHighwaywhichhasbeen-rivercorridorthatprovidesforprotectionofvisualrecommendedasascenichighway,wouldbeinundated.resources.DamabutmentwouldbeconstructedonKobeHill,•TowerBluffRapids,whichisofnotablescenicquality,recommendedasascenicstatetrailandPublicwouldbeinundated.RecreationReserve..'•LandinTananaValleywhichhasmoderatescenicquality,wouldbeinundated. IACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTIIlocalizedherds.insurroundingItinlong-termlwnbearuseofItensivebrownhatwouldbeitsalongriver.,1use.ALTERNATIVESSNOW.4,110•Importantspring,fall,andwinterrange.•Caribounotpresent.Dallsheepandmountaingoatsmainlyathigherelevationsinsurrounding mountains.Increasedaccessmayresultinlong-termimpactsonlocalwildlifepopulations.•Blackbearuseoffloodplainarea.Brownbearuseofhighaltituderipariancommunities.•Importantriparianhabitatalongriverandonfloodplain.•Baldeaglenestingarea.Waterfowlnestingandmoltingarea.CHAKACHAMNA.1,870•Importantwinterareasinriparianhabitatabovelakeandinriverdrainages.•Littlecaribouuseofarea.DallsheepmainlyathigherelevationsnorthoftheChilliganRiver.•Highaltituderiparianzonesimportanttobrownbear.Highblackbearuseofriparianzonearoundlakeandinriverdrainages.Brownbearseasonalspecificuseofdrainageduringsalmonruns.•Importantriparianhabitataroundlakeandalongriver.•Trumpeterswannestingareasindrainages.MoltingareaforTulewhite-frontedgoose.Drainagesinmajormigrationcorridor.TOTALNON-SUSITNAHYDRO.123,370•Importantyear-roundhabitat(especiallycalvingandwinteringareas).Johnsonprojectwouldsubstantiallyimpactlocalmoosepopulation.•Littleuseofareabycaribou.LittleuseofareasbyDallsheep.Increasedaccessmayresultinlong-termimpactsonlocalwildlifepopulations.•Nodataondenninginareas.Keetnaprojectwillimpactintensivebrownbearuseofcriticalsalmonstreams(eg.PrairieCreek).Lake Chakachamnaprojectwillimpact.brownbearuseofChilliganandChakachatnaRiversIsalmonfisheries.Allsitescontainimportantyear-roundblackbearhabitat(especiallyriparianzones).•Importantriparianhabitatalongrivers.•Nestinglocationsatallsitesforraptors(especiallybaldeagles).PeregrinefalconnestlocationsatJohnson.site.ImportantwaterfowlnestingandrestingareasatJohnsonandLakeChakachamnasites.TrumpeterswannestingareasassociatedwithLakeChakachamnaproject.SUSITNA•57,620•Approximately1.5moose/mi2.Importantyear-roundhabitatespeciallywinterrangeandcalvingarea.•Caribouspringandfallmigrationcrossingarea.ImportantsitespecificareaforDallsheep(ie.lick).Increasedaccessmayresultinlong-termimpactsonlocalwildlifepopulations.•Importantyear-roundhabitatforblackbearincludingdenning.Importantspringhabitatforbrownbear.•Importantriparianandforestedhabitatsalongriver.•Nestinglocationsforbaldeagles,goldeneagles,andgoshawks.Lowwaterfowluse.Table9COMPARISONOFTERRESTRIALRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Table9-COMPARISONOFTERRESTRIALRESOURCESANDIMPACTSAMONGNONSUBJECT,~f:"iALJOHNSONBROWNEKEETNA1.AREAINUNDATEDORAFFECTED(Acres)..98,160.13,090•6,140.4,110•Approximately1moose/mi2.•Approximately1-1.5moose/mi2.•Importantyear-roundhabitat.•Importants~2.MOOSEImportantyear-roundhabitatespeciallywinterrangeImportantyear-roundhabitat.andcalvingarea.•Littleuseoftheareabycaribouexceptinsevere•Cariboufrequentthefoothillsnearimpoundment.•Littleuseoftheareabycaribou-smalllocalizedherds.•Caribounot3.OTHERBIGGAMEwinters.DallsheepmainlypresentathigherelevationsDallsheepmainlypresentathigherelevationsinDallsheepmainlyathigherelevationsinsurroundingmainlyathi!insurroundingmountains.surroundingmountaills.mountains.Increasedaccessmayresultinlong-termIncreasedaCIimpactsonlocalwildlifepopulations.localwildlifE•Brownbearuseinearlyspring.Highuseofvalley•Importantbrownbearhabitatinsurroundingfoothills.•Blackbearuseoffloodplainarea.Brownbearuseof•Blackbearu:bottomsbyblackbears.Lowblackbearuseofarea.highaltituderipariancommunities.Intensivebrownhighaltitude4.BLACK/BROWNBEARbearuseofanadromousfishstreamsthatwouIdbeblockedbyproject.5.FURBEARERS•Importantriparianhabitatalongriverandinwetland•Importantriparianhabitatalongriver.•Importantriparianandforestedhabitatsalongriver.•Importantriandforestedareaswithinthefloodplain.floodplain.•Importantnestingareaforbaldeagles,goldeneagles,•Littleraptororwaterfowldataavailable.•Baldeaglenestingarea.Lowwaterfowluse.•Baldeaglem6.RAPTORS/WATERFOWLandred-tailedhawks.Fourperegrinefalconnestarea.locations(threeactive)alongshorelineofimpoundmentarea.Importantwaterfowlnesting,molting,andrestinghabitat.Majormigrationcorridor... ACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECTJ.ALTERNATIVESSUSITNASNOWCHAKACHAMNATOTALNON-SUSITNAHYDROresent,spawning•Nospawningaboveimpoundmentzone.•Largenumbersofsockeyespawnintributariesabove•Salmonfoundupstreamofallsites(exceptSnow).•Nonerecorded;passageessentiallypreventedbyDevilveandsupportsathesite;escapementestimatedat40,000adults.~IHighlysignificantnumbersareknowntoexistCanyon..certainperiodsupstreamofKeetnaandChakachamnasites.intment·Creek•Reportsindicatethatsockeyearepresentinlower•Somesockeyespawningareascouldbewithinthe•Salmonpresentin allimpoundmentzones;Johnson•Noneexceptforafewchinook;passagetothisareaisParadiseLake(seetextfordetails).drawdownzone;juvenilesockeyeuseChakachamnaandKeetnaimpoundmentsencompassknownessentiallypreventedbyDevilCanyon.forrearing.spawningsites.ydownstreamof•SockeyeandcohospawninlowerSnowRiver;allfive•Allfivesalmonspeciesutilizedownstreamareasineither•Allsiteshavesignificantsalmonhabitatdownstream.•Allspeciesutilizeeitherdownstreamareasorltreamareasorspeciesutilizeeitherdownstreamareasortributaries,theChakachatnaorMcArthurRivers.Totalnumbertributaries.particularlyintheKenaiRiver.ofadultsintheseriversareapproximately60,000."tandcommercial•Significantandhighlyimportantsportandcommercial•Believedtobesignificantandimportanttosportand•Salmonfromallsitespotentiallycontributeto•Significantandhighlyimportantsportandcommercial)werSusitnafisheriesintheKenaiRiverandCookInlet.commercialfisheriesdownstreamandinCookInlet.significantandhighlyimportantcommercialfisheries fisheriesinlowerSusitnaandCookInlet;noandinsomecasestohighlyimportantsport(e.g.,contributionbyareaupstreamofDevilCanyon.KenaiRiver)andsubsistencefisheries.byinundation.•Tentativedisruptionofupstreamanddownstream•Lossofspawningandrearinghabitatbyimpoundment•Lossofsignificantspawningandrearinghabitatby•Changesindownstreamrearingandspawninghabitat.passage(seetextforclarification)levelchanges.inundation.~ampassage.Irearinghabitat.•Tentativelossofspawningandrearinghabitatby•Disruptiononupstreamanddownstreampassage,•Disruptionofupstreamanddownstreampassage.inundation.particularlyfordiversionfromoneriversystemtoamofsite.another.•Extensiveareasofdownstreamspawningandrearing•Changesindownstreamspawningandrearinghabitat.habitatchanged.•Extensivechangesindownstreamspawningandrearing•LossofchumsalmonresourceaboveJohnson,Browne,habitat.andKeetnasites.Table10COMPARISONSOFAQUATICRESOURCESANDIMPACTSAMONGNON-SUSITNAHYDROALTERNATIVESANDTHESUSITNAPROJECT Table10-COMPARISONSOFAQUATICRESOURCESANDIMPACTSAMONGNOrSUBJECTALJOHNSONBROWNEKEETNA•ChumsalmonspawnasfarupstreamastheChisana•Coho,chum,andchinookpresent;cohospawninCoho,chum,sockeye,andchinookpresent,spawning•Nospawnir1.ANADROMOUSFISHUPSTREAMOFRiver;escapementfiguresunknown.PanguingneCreek;escapementfiguresunknown.bychinookinPrairieCreekisextensiveandsupportsaIMPOUNDMENT!PROJECTSITEsignificantbrownbearpopulationforcertain periodsoftheyear.1/•Chum,coho,chinookpresent;chumspawning•Coho,chum,andchinookpresent;escapementfigures•ChumandchinookspawninDisappointment·Creek•Reportsinc2.ANADROMOUSFISH!IMPOUNDMENTZONEobserved;escapementfiguresunknown.unknown.andpotentiallythemaihstem.ParadiseLc•Allfivespeciesutilizeeitherdownstreamareasor•Allfivespeciesutilizeeitherdownstreamareasor•Chumspawninmainst~mimmediatelydownstreamof•Sockeyear3.ANADROMOUSFISH!DOWNSTREAMtributaries.tributaries.damsite;allfivespeciesutilizedownstreamareasorspeciesutiltributaries.particularl~•Extensivelyandextremelyimportantcommercial,•Extensiveandextremelyimportantcommercial,•Significantandhighlyimportantsportandcommercial•Significant4.UTILIZATIONOFANADROMOUSFISHsubsistence,andsportfisheriesinthelowerTananasubsistence,andsportfisheriesinthelowerTananafisheriesinthelowerTalkeetnaandlowerSusitnafisheriesinandYukonrivers.1/andYukonrivers.1/riversandCookInlet.,,•Lossofspawningandrearingareasbyinundation.•Disruptionofupstreamanddownstreampassage.•Lossofspawningandrearinghabitatbyinundation.•Tentativec•Disruptionofupstreamanddownstreampassage.•Changesindownstreamspawningandrearinghabitat.•Disruptionofupstream'anddownstreampassage.passage(se•Changesindownstreamspawningandrearinghabitat.•Lossofchumsalmonresourceupstreamofsite.•Changesindownstreamispawningandrearinghabitat.•TentativeI,5.POTENTIALIMPACTSOFPROJECTONinundationANADROMOUSFISH•Lossofchumsalmonresourceupstreamofsite.•Lossofchumsalmonresourceupstreamofsite.•Changesin1/Thismatrixonlyconsidersanadromoussalmon-residentspeciesarediscussedinthetext.DistributionsfortheanadromousspeciesaretakenfromtheAlaskaDepartmentofFishandGame'sAnadromousWatersCatalogue(1983);1/Source:Bentz,Jr..R.W.1982.InventoryandcatalogingofthesportfishandsportfishwatersinupperCookInlet,Table8,page102.~/Source:BechtelCivilandMinerals,Inc.1983.Chakachamnahydroelectricprojectinterimfeasibilityassessmentreport.1./Source:AlaskaDepartmentofFishandGame,1983.AnnualManagementReport1983-Yukonarea.DivisionofCommercialFisheries. 1,215.17927.47495.421,745.232,880.597,263.885,565.00~COST,JANUARY1982LEVEL($x106)xFxFxFxFxFCOMMONESCALATION'\~ACTOR,Fl1JBOTH1\~80AND1982COSTSARE,COMPUTEDVALUES;THEYPROVIDEBASIS/FORESCALATION/F~eTOR/2,860.00COST,!JJULY1980LEVEL($X106).-624.51~",476.65(~/)254.61896.92'.1,480.41,/__?,ZS3:'10PROJECTlUJ{~>TABLE11:DEVELOPMENTOFJANUARY'1982LEVEL;HYDROELECTRICCOSTSl!rJ1(:'/',"ALTERNATiVE'S"BROWNEJOHNSONKET;;',/IVIt~EETN'A,5Nt'U')--~.......SNI."'·\lAL'\.~;I.)i\'/"",J"'QTrt-,jv'It(\!!j"Ji,t/:-~.iCHAKACHAMNAALTERNATIVESTOTAL'~-'~",--I'l~jr--------.."...-----..------........---.'1J-J~j',',1.SUSITNA.(WATANA&DEVILCANYON)'1--j]]]COSTNOTINCLUDEDINLICENSEAPPLICATIONTOFERC,BUTCOMPUTEDFORTHIS..STUDYUSINGESTIMATEDQUANTITIESANDJULY1980LEVELUNITPRICESFORBROWNE,KEETNA,.,ANDSNOW\~COSTPROVIDEDINLICENSEAPPLICATIONTOFERC,"SUSITNAHYDROELECTRICPROJECT,VOLUMEI,INITIALSTATEMENT:'ACRESAMERICAN.,INC.,FEBRUARY1983'COSTPROVIDEDINLICENSEAPPLICATIONTOF~lRC,c,\\~,~~E~OP!AEN!"SELECTION..REPOR!~'ACRESAMERICAN,INC.,DECEMBER198J~~-~!,Vf77C;?"~~1!:jJ!)--6~~'.::JI'Y-7hd'Sk>c'l:,,~.]~F =SUSITNA1982COST=~5.~~;r,;= 194:;;V/i~5e--?!''1""ERes<bJf.fb~SUSITNA1980COST$2,860X10?.JJ'!J,11,J11-k.;~~~"~'-'ft/;}4.,;-'~"-<:.,-'1{I.'V/'v'",-,ct!,-:.:t;:~,l.~j-.I,.".'.v"t,,',-""..,~:"J(/e:.o...f\,,/-...2(..1..,-(•.1', '--"---" I '--L-.........J '----.J r'L-J '----.i ., l...--J ~ 1 ~C-..-----i -----J ~1 --...J l?;A1I /0 ,~~.M .L' G,~C,~L:--:~:~'-~ r'_.o_~\,\;..,-~~~ TABLE 12:COMPARISON OF INDIVIDUAL HYDROELECTRIC ALTERNATIVES \ INSTALLED 2J AVERAGE CAPACITY ANNUAL (MW)OUTPUT (GWh) -- 100 •430 210 920 100 420 63 278 330 1,301 1,040 3.260 PROJECT BROWNE JOHNSON KEETNA SNOW CHAKACHAMNA WATANA DEVIL CANYON TOTAL COST,1J JAN,1982 LEV!'L •. ($x 10 6 ) l,215:.I_~_I /1 7 iut:::f3'r ': /'927.H ! f~7,t;!?I .4-9--5,,-\<2' .""P',''''~J,;/""'/l"."jj F<-I'_"",·?i~~,~~· ~2.880.~_~ /:.,J" ;;/3,6 1 9.2 O~ ,~1\ W 1,945.80 .......1·,I...~-_.-~'.P'i'580 3.310, ~I COST PER I COST PER I MAXIMUM ACTIVE COST PER ACRE-FT REQUIRED ACTIVE INST ALLED MW GWh RESERVOIR RESERVOIR OF ACTIVE RESERVOIR AREA RESERVOIR ($x 10 6/MW)($x 10 6/GWh)SURFACE AREA VOLUME STORAGE PER GWh REQUIRED PER MW (ACRES)(ACRE-FTl ($1 ACRE-FTl (ACRES/GWh)'(ACRE-FTIMW) 12.1 ~I 2.83 12,500 760,000 1,599 29.1 I 7,60 C '")..-.:?;;~I4.42.l,oi 94,500 5,300,000 C~.7 5 102.7 I 25,238,i '"??r~-;;.. 4.95 1.1 8 5,500 500,000 991 ';I 13,1 I 5,000,, (~r~~....;"1 ~;~•.•...,-"<............ 6.26 3,200 174,000 10,030 "/f 1 I.5 I 2.762, 8.73 2.21 17.280~1,105,000 2,607 13.3 3,348 3.48 I 1.1 1 38,000 3,000,000 1,206 1 I.7 2,885 3,35 I 0.59 I 7,800 I 350,000 5,559 2.4 603 1984 /to )'r.f .!--'t,~..>,#J ',,' J I ",.~r'" /,,,,({~,",/-~'>''; \i 'L/.~/·-('G/, { " ~\ ,,,,,,.f:,£"t.S~f.)'..\:~.,IJll!V,L)TABLI~:14.<.f"-:,:;.::(",\/I WWl e:/ .'.\\\'.(Ii REPORT NON-SUS,lTNA HYDROELEC;TRI?,~L/,;~ERNATIVES.HARZA-EBASCO.JULY ,/j //'t,"0 EXISTING LAKE /f "'){/{/t//..~. .h,;-,v (. 1J ~ ~ -:)]]]._]]JI,-'11,J_1TABLE13:ALTERNATIVESVS.SUSITNAJANUARY1982LEVELFIGURESCOMPARISONALTERNATIVES11SUSITNA~COST($x106)7,263.885,565.00INSTALLEDCAPACITY(MW)8031,620AVERAGEANNUALOUTPUT(GWh)3,3496,570MAXIMUMRESERVOIR~115,70045,800SURFACEAREA(ACRES)-ACTIVERESERVOIR7,839,0003,350,000VOLUME(ACRE:'FT"IUNITCOSTPERINSTALLED9.053.44CAPACITY($x106/MW)UNITCOSTPERAVERAGE2.170.85ANNUALOUTPUT($x106lGWh)COSTPERACRE-FTOF9271,661ACTIVESTORAGE($(ACRE-FT)REQUIREDRESERVOIRSURFACE407,AREA41PERGWh(ACRES/GWh)ACTIVERESERVOIRREQUIRED9,7622,068PERMW(ACRE-FTIMW)11BROWNE,JOHNSON,KEETNA.SNOW,CHAKACHAMNAiTABLES1AND2~WATANA,DEVILCANYON;TABLES1AND23jEXCLUDINGCHAKACHAMNALAKE4.JINCLUDINGCHAKACHAMNALAKE ~1'jTABLE14]BASICDATAFORFIVEALTERNATIVESITESANDTHEPROPOSEDSUSITNAPROJECT~-1ProposedAlternativeSitesProjectChaka-Devil']BrowneJohnsonKeetnaSnowChamna*WatanaCanyonLJSERVOIRELEVATIONS(ft)1Maximum9751,4709451,2001,1282,1851,455-Minimum8901,3908201,0501,0142,0651,405'lEA~1000ac:-ft)12.594.55.53.215.238.07.8.-Max1mum'JORA~E(1000ac-ft)1,1007,0008501794,0339,4691,092-Max1mumMinimum3401,70035062,4245,732.741jActiveStorage7605,3005001731,6093,737351(l000ac-ft)(Daysofmeanflow)8527310113221623720rlWERPLA~TPowerTunnel(mi)2.312.0'1RatedHead(ft)170 149286620663680590~...InstalledCapacity(MW)100210100633001,020600...Hydr.Capacity(cfs)8,75021,5005,2101,5006,40420,00015,000lEnergyProd.(GWh/yr)4444234292661,1523,4993,435,-DecemberAvg.Cap.(MW)27792126107720500•JT.w.Level(ft)7801,2906155004001,455850(Inter-STREAMFLOWvening)(Total)IDrainageArea(sq.mi)2,45010,500.1,2601051,1205,1806305,810.JYearlyAvg.(cfs)4,5009,8002,5006603,7507,9901,1019,080)JuntoAugAvg.(cfs)11,60023,4006,5001,82010,28020,5982,55323,151..JSeptoMayAvg.(cfs)2,1005,3001,2002701,5703,6946124,300MJNIMUMFLOWREQ.'cfs)JuntoAug9,30024,0005,0007409,9008,180..SeptoMay1,4003,2007202101,1005,6851!I*-A1ternativeD.1J453410/TBL1840820J '1r-1TABLE15]ALTERNATIVEHYDROPROJECTSMONTHLYAVERAGEFLOWANDMINIMUMRELEASEINSUMMERrjDEIS~INon-SusitnaSummerMeanC]HydroMinimumAnnualAverageMonthlyAlternativeReleaseRunoffStreamflow(cfs)DataSites(cfs)(cfs)JuneJulyAugustSourcecJBrowne9,3004,50012,60812,18010,077BrowneHydroAlt.byJBattelle,Aug19822..1]Johnson24,0009.80018,32826,45225,468USGSStream-flowDataJKeetna5,0002,5007,2146,318-5,855ResponsestoAdditionalJDataRequestbyAPAAug.181983License]App.forMajorProject'JSnow7406601,6322,1161,692SurfaceWaterRecords,CookInlet,thru1975,USGS2..1JChakachamna9,9003,7508,93811,81810,098Bechtel19831cl]_JJIISburceTable2-7,DEIS,May1984.2TheUSGSflowrecordsatthenearestgagingstationwereusedtoestimateflowsatthedamsite.453410/TBL840820 ALTERNATIVEHYDROMINIMUMSUMMERCAPACITYINDEISTABLE16']'J'1]]]Non-SusitnaAlternativeHydroProject./BrowneJohnsonKeetna.Snow.!.!Chakachamna.f.1TotalInstalledCapacity(MW)100210100100300773CapacityBasedOnMin.Discharge(MW)118256103336241134J]]]~JJJ]J453410/TBL840820IIInstalledcapacityof100MW~nDEISwasrevsedbyApplicantto63MW.!.~IIBasedonAlternativeD. ]J]]c11.J.IJ]TABLE17ALTERNATIVEHYDROHYDRAULICCAPACITYCOMPUTEDFROMINSTALLEDCAPACITYINDEISNon-SusitnaSummerAverageAlternativeMinimumFlowPercentHydroProjectMaximumHydraulicCapacityRequirement·Spilled(cfs)(%meanflow)(cfs)(%)Browne8,7501749,3006Johnson.21,50021924,00010Keetna5,2102085,0000Snow2,3802277400Chakachamna6,4041719,900354534l0/TBL840820 --j')TABLE18'1(GWh)ALTERNATIVEHYDROENERGYPRODUCTION'---YEAR2010LOADCONDITIONS~1JanFebMarAprMayJunJu1AugSepOctNovDecAnnualJJSystem659582 5754914594274204464655636407176444Requirement]ExistingHydro5145.44384344495347515152568Alternative]SitesIISnow171514121435373925192019266'1Keetna151213121780848455261516429Browne18151513177883 8355262120444']Chakachamna7264635462189166 187816570801152]Johnson5448474035I'1043435259423]"Subtotal1761541521311453833713832591791781942714TotalHydro2271991961091884274204463062302292463282"JNon-Hydro43238337932227100 01593334114713162COOlRequirementI~_JSpilled0000037942139594 0 012081EnergylJ.JIIAlternativeplantsarelistedintheorderofsimulation,thatis,startingJfromthesmallestreservoirstoragevolumeandendingwiththelargest.2JSpillsduetovalvereleaseforminimumreleaserequirementorduringfloods.).JJ,)453410/TBL1840820.J IrrjTABLE19jALTERNATIVEHDYROENERGYPRODUCTION(GWh)YEAR2010LOADCONDI~IONS,r]JanFebMarAprMayJunJu1AugSepOctNovDecAnnualrJSystem659582575491459427 420 4464655636407176444RequirementIExisting51454438434449534751 5152568Hydro~l.AlternativeSits1./Browne1815 1513·177883 8355262120444oJKeetna15131312178084·8455261516430:1Snow171514131335383923 201920266r]Chakachamna7364 635362189 165187816570791151Johnson54484740341 1042435159420jSubtotal177 155152131143383 3713932561801761942711:JTotalHydro228200196169186427420 44630323122724632791Non-Hydro4313823793222730 0 01623324134713165cJRequirement]Spilled0 0 00 03774203949 40 01204JEnergyl/1./Alternativeplantsarelistedintheorderofsimulation,thatis,startingfromthesmallestreservoirandendingwiththelargest(measuredindaysof)meanflow)•.J2..1Spillsduetovalvereleaseforminimumreleaserequirementorduringfloods.]cJ1453410/TBLc1840820 ~-1.J'lTABLE20~'IALTERNATIVEHYDROENERGYPRODUCTION(GWh)YEAR2010LOADCONDITIONS:1JanFebMarAprMayJunJu1AugSepOctNovDecAnnual'ISystem6595825754914594274204464655636407176444)"Requirement'JExisting51454438434449534751 5152568Hydro'-'1,JAlternativeSitesJJJChakachamna7062 625263207215217896769771249Snow171514121335383924202019266'IKeetna15121312 1780 8584.55261516430'JBrowne181515 1317613353 54262120346.1Johnson544847 403511 043425159419--Subtotal174152150129145383371j3932651811761912710cJ.TotalHydro225197194 1671884274204463122322272433278.JNon-Hydro434385 3813242710 0 0153331413 4743166Requirement:JSpilled0 0 0 0 03804153979 4 0 01205.Energy1/Ij1./Alternativeplantsarelistedintheorderofsimulation.TheChakachamnasite,astheoverallmostfavorablesiteamongthefive,wasputinfirstandtheJohnsonsite,theleastfavorableamongthefive,wasputinlast.1/Spillsduetovalvereleaseforminimumreleaserequirementorduring')floods•.]J453410/TBL1840820.1 '1cJTABLE21COMPARISONOFALTERNATIVEHYDROENERGYPRODUCTION-YEAR2010LOADCONDITION(GWh/yr)ProjectAverageAnnualEnergybyHEC-5~/AverageAnnualEnergybyRESOPZ/'1.JBrowne418444Johnson920423J./Keetna420429Snow375266Chakachamna1,3001,152Total3,4332,714IeJ1e.l)..J453410/TBL]840820e_J1/2../:i/Table1-18,DElS,May1984PowerAuthoritydataLimitedbysystemenergyrequirements.Withoutsystemenergylimitation,Johnsoncouldproduce946GWh. l'1, JTABLE22DEPENDABLECAPACITYBYSIMULATIONWITHBESOPr1J'1,11j1I.JProjectBrowneJohnsonKeetnaSnowChakachamnaTotalDependableCapacity(December)(MW)27792126107260,J)J),J1J1J453410/TBL840820Note:Basedonproje~tedRailbeltpeakdemand1n·year2010. EXHIBITS LEGENDBROWNE'1-\~AlaskaMountain~~Range~~-:P•ALTERNATIVEHYDROELECTRICPROJECTSASUSITNAHYDROELECTRICPROJECTStNz~r------___,r--------=-....,.....,...___:'--_::,...----,<0o,...zo'<t<0Z~-r---_<0zoC\J<0zoo<0zo~:1:S:3:-0:W:-:---~1-S-10"""W--.....l---1-4-9""O-W------14-7-,Or--W-----1-4-S""T'O-W-----oI50ISCALEINMILES100IALASKAPOWERAUTHORITYALTERNATIVEHYDROELECTRICPROJECTSLOCATIONPLANIIun~IEXHIBIT~...............,1._.-._-'6/1984 TRANSMISSIONLINEPLANSUSITNAHYDROELECTRICPROJECTALASKAPOWERAUTHORITYO~I~~250iiiiiiiiiiiiiiiif"IUS/-J1,,£~---?YIIfCON..c----..--""-.-------~;4___-.."",r7V7-~-------_\L-------T$SoHLEGEND:NOTE:-REFERENCEDRAWINGPLATEG4,EXHIBITG·OF"SUSITNAHYDROELECTRIC.PRoJECT,.APPLlCATIONFOR:LICENSEFORMAJORPROJECT.VOLUME4/~ACRESAMERICAN}INC.,FEBR.UAR.Y1983.)o(XXX..1...11..""~..--......--..""'-.~ '.-<MEeO--~r::E::X~HIBIT3"""6MI.I3MI.SCALEPOWERAUTHORITYALASKAHYDROELECTRICPRR(O),J!!:E~C:..'..T,•--SUSITNA0 NJOHNSRESERVOIRDAMANDPLAN SCALEALASKAPOWERAUTHORITYo2000Ft.1Mile2Milesi~~~~~~iNOTE:BASETOPOGRAPHYFROMUNITEDSTATESDEPARTMENT>OFTHEINTERIORGEOLOGICALSURVEY(USGS)FAIRBANKS(A-5,B-$)QUADRANGLEMAPS(SCALE1:63,360;100FOOTCONTOURINTERVAL~BROWNEDAMANDRESERVOIRPLANSUSITNAHYDROELECTRICPROJECT.><.),,~'--"'----~~....},-,:-f~-,-'..J,;i~;c----:ro-,,,-j>/-',d?--/,-'.~,;;}!le:/'"(J'.~.1./"t#'---:'-=-:':~-:::'::"-:"..'.'~,:,.~~~~0~'f-·t~tii·)··~·~···~·-i··{v·,··v··-~L~~~m-;;~~DL~t~~i~~!;!~'~';'IIIIIIIIII··:·:··",······,·::·"····:····4'/11//·,--.oHIGliWAYo~CO~BINED_"WJT}f:~-:~~<__,.~~~~;'4.~~.~-.,.,1"">:::/TRANSMtSSJONINTE~nE.-:-'".--.'.-._~--'JG5>-~:....;'••_f-;"":::'-;'::-~,",::cc.:·.o:---,;;;-4:I\~'-,---"',,_.-f SCALEALASKAPOWERAUTHORITYSUSITNAHYDROELECTRICPROJECTKEETNADAMANDRESERVOIRPLAN5 SUSITNAHYDROELECTRICPROJECTALASKAPOWERAUTHORITYSCALEEXHIBIT6SNOWDAMANDRESERVOIRPLAN"o2000Ft.1Mile2Milesii__~~~~i o1Mi.3Mi.8Mi.EJ._~i~~~iSCALENOTE:BASETOPOGRAPHYFROM,UNITEDSTATESDEPARTMENTOFTHEINTERIORGEOLOGICALSURVEY(USGS)"QUADR:ANGLEMAPS(SCALE1:83J380;100FOOTCONTOURINTERVAL)..ALASKAPOWERAUTHORIl'7Y'SUSITNAHYDROELECTRICPROJECTSUSITNAPROJECTDAMSANDRESERVOIRSPLANAPPROVEDDATE 1Mile2Miles_iiiiiiiiii~~~~~~~---,1SCALEALASKAPOWERAUTHORITYSUSITNAHYDROELECTRICPROJECTCHAKACHAMNADAMANDRESERVOIRPLAN