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s 627.883 N7NNDD DEPARTMENTOFNATURALRESOURCES 2007 AND CONSERVATION 1 BGROIVAENRSNCOHRWEITZER DITREELCETFOARX'NSUOMFFBIECRE((440066))444444--22067844 STATE OF MONTANA ThWtEAtLpTE:E/F/RAwXwRwEN.SdUnOMrUcBRmEtC.REgSoSvD(4I0V6)IS44I4O-N05(34306/)(444046-)6464041-5918 HELENA,MON14T2A4PN9OTABH5OA9X6V22E00-N1166U00E11 Distributionlist/EAcoverletter: April9,2007 TO:GEonvveirrnoonrm'esntOaflfiQcue,alBirtyucCeouNneclislo,nC,apRimt.ol2B0u4i,ldSitnagt,eRCoapoimtol1,06P,.OP..OBoBxo2x02008107104,,HeHleelnean,a,MTMT595692602-00801 MMTTDDeepptt..oEfnvNiartournamlenRteasloQuuracleitsy,anMdetCcoanlsfeBruvialtdiionng,,PU.SO.FB&oGxB2l0d0g9.0116,2H5el1e1n*a,AvMeT.5H9e6l2e0n-a0,9M01T59620 Director'sOffice InformationServicesSection JWaanteLranRgeeslo,uHrecleesnDaivRiesgiioon,na1l4O2f4fi9cteh,Av1e4.2,4P9.tOh.AvBeo.xP2.0O1.6B0o1x,H2e0l1e6n0a1,,MHTele5n9a6,20M-T165091620-1601 MTDept.ofFish,Wildlife&Parks,1420E.6thAve. Helena,MT59620 Director'sOffice GaryBertellotti,RegionalSupervisor,FWPR4,4600GiantSpringsRd.POBox6610,GreatFalls,MT59230 BrentN.Lonner,WildlifeBiologist,FWPR4,FreezeoutLakeOffice,P.O.Box488,Fairfield,MT58536 MikeMadel,WildlifeBiologist,FWPRegion4,RR2Box225,Choteau,MT59422 DaveYerk,FisheriesBiologist,FWPRegion4,P.O.Box733,Choteau,MT59422 MTStateParksAssociation,P.O.Box699,Billings,MT59103 MTStateLibrary,1515E.SixthAve.,P.O.Box201800,Helena,MT59620 DickArtz,NilanWaterUsersAssociation,EberlLn.P.O.Box262,Augusta,MT59410 MontanaEnvironmentalInformationCenter,POB1184,Helena,MT59624 MontanaAudubonCouncil,P.O.Box924,Helena,MT59624 Lewis&ClarkCountyCommissioners,316N.ParkAve. Helena,MT59601 WildlifeFederation,P.O.Box1175,Helena,MT59624 TroutUnlimited,P.O.Box7186,Missoula,MT59807 U.S.ArmyCorpsofEngineers,10West15thSt.,Suite2200,Helena,MT59626 U.S.FishandWildlifeService,MTFieldOffice,100N.Park,Suite320,Helena,MT59601 LadiesandGentlemen: TheencloseddraftEnvironmentalAssessment(EA)hasbeenpreparedfortheNilanNorthDamOutletRepairProjectand issubmittedforyourconsideration. Pleasefeelfreetocontactmeat(406)444-6605shouldyouhaveanyquestionsor comments.Commentscanbemailedore-mailedtotheMTDNRC,StateWaterProjectsBureau,14249lhAve,P.O.Box 25:001060p1.m,.HJeuleensad,ayM,TM5a9y6280th-21060071.,aTthteentdiroanftJEaAmecsanP.beDovmiienwoe,deo-nmlaiinlejadt:omhittnpo:@/m/tw.wgwo.dvn.rcC.motm.mgeovn/tesnvwildlocbse/daecfcaeupltte.dasupn.til CopiesofthedraftEAarealsoavailableuponrequest.Thankyouforyourinterest. APR I02007 MONTANASTATELIBRARY HELEN15A1,5MEO.N6tThAANVAE.59620 STATEWATERPROJECTS WATERMANAGEMENT WATEROPERATIONS WATERRIGHTS BUREAU BUREAU BUREAU BUREAU (406)444-6646 (406)444-6637 (406)444-0860 (406)444-6610 9889 3 Draft Environmental Assessment Dam Nilan North Outlet Repair Project April2007 TableofContents Page 1 PartI. ProposedAction Description TypeofProposed StateAction AgencyAuthority ProjectName ProjectSponsor Construction Timeline ProjectLocation Page2 ProjectSize Agencieswith overlappingjurisdiction Permits Needed Funding NarrativeSummary Page4 ProjectMap Page5 ProjectPhotographs Page7 PartII. Environmental Review Alternatives and ProposedAction Evaluation and Listing ofMitigation PartIII. Public Participation Page8 PartIV. EA Preparation Page9 PartV. Environmental ReviewChecklist A.Physical Environment-Land Resources Page 10 Air Page 11 Water Page 12 Vegetation Page 13 Fish/Wildlife Page 14 B. Human Environment-Noise/Electrical Effects Page 15 Land Use Page 16 Risk/Health Hazards Page 17 Community Impact Page 18 PublicServices/Taxes/ Utilities Page 19 Aesthetics/Recreation Page20 Cultural/Historical Resources Page21 C. Significance Criteria Page22 PartVI. Narrative Evaluation and Comment Page23 AppendixA Nilan North Dam OutletRepairProject DraftEnvironmental Assessmentand MEPAChecklist PARTI. PROPOSEDACTIONDESCRIPTION 1. Typeofproposedstateaction: TheStateWaterProjectsBureauoftheWater ResourcesDivision,DepartmentofNaturalResourcesandConservation(DNRC), proposestorepairtheterminaloutletstructureontheNilanNorthDam. Therepair workincludesreplacingtheoutletstructureandinstallingfiltersanddrainsatthe outletterminalstructuretocontrolandcollectseepage. 2. Agencyauthorityfortheproposedaction:TheMontanaLegislatureenacted statute85-1-101 MCA,whichauthorizestheDNRCtoconstruct,operateand maintainasystemofworksfortheconservation,development.,storage, distribution,andutilizationofwater,whichconstruction,operationand maintenanceisasingleobjectiveandisinallrespectsforthewelfareandbenefit ofthepeopleofthestate. 3. Nameofproject: NilanNorthDamOutletRepairProject 4. Name,addressandphonenumberofprojectsponsor(ifotherthanthe agency): TheDNRCistheprojectsponsor. 5. ConstructionTimeline: EstimatedConstruction/CommencementDate: October2007 EstimatedCompletionDate:December2007 CurrentStatusofProjectDesign(%complete):80% 6. Locationaffectedbyproposedaction(county,rangeandtownship): TheNilanNorthDamislocatedinLewisandClarkCounty,Township20N, Range7W,Sections17and18. SeeFigure1 onpage4forlocationmaps. 1 Projectsize--estimatethenumberofacresthatwouldbedirectlyaffected thatarecurrently: Acres Acres (a) Developed: (d) Floodplain Residential 0 Industrial 0 (e) Productive: Irrigatedcropland (b) OpenSpace/Woodlands/Recreation 0 Drycropland Forestry (c)Wetlands/RiparianAreas 0 Rangeland 0 Other(earthendam) 1/2 8. ListingofanyotherLocal,StateorFederalagencythathasoverlappingor additionaljurisdiction. (a) Permits: Allpermitswillbeobtainedpriortoapplicableproject construction. AgencyName Permit USCorpsofEngineers Section404(ifrequired) DNRCMontanaDamSafety ConstructionPermit(ifrequired) (b) Funding: AgencyName FundingAmount DNRC $113,608 (c) OtherOverlappingorAdditionalJurisdictionalResponsibilities: AgencyName TypeofResponsibility StateHistoricPreservationOffice CulturalResourceProtection 9. Narrativesummaryoftheproposedactionorprojectincludingthebenefits andpurposeoftheproposedaction: TheNilanNorthDamislocated6mileswestofAugusta,MontanainLewis&ClarkCounty. ThedamisownedbytheMontanaDepartmentofNaturalResourcesandConservation. The dam,oneoftwoonthereservoir,isanearthfillstructureconstructedin1951 andisclassifiedas highhazard,whichmeanstheremaybelossoflifeifthedamweretofail.TheNorthDamhasa lengthof530,acrestwidthof20feetandis54feethigh. Thereservoircanstoreapproximately 10,000-acrefeetofwateratfullpool. TheNilanWaterUsers'Associationisresponsibleforthe operationandmaintenanceofthedam. Thereservoirisapopularrecreationarea,withfishing theprimaryattraction. 2 Therepairworkincludesreplacingtheoutletstructureandinstallingfiltersanddrainsatthe outletterminalstructuretocontrolandcollectseepage.TheoutletstructureattheNorthDamis structurallyinverypoorconditionandhasdeterioratedtothepointthatadditionalsmallrepairs andpatchingarenoteconomicalorfeasible. Theacceleratingdeteriorationisprimarilya functionofcontinuousfreeze-thawdamage,severecracking,andage. Thereisalsoa considerableamountofseepagethatexitsinthelocationoftheoutlet. Uncontrolledseepage alongthesideoftheconduitcouldcausematerialtoberemovedfromthedamembankment andcausefailureofthedam. Theproposeddraininstallationwouldencircletheendofthe conduittosafelydischargeseepagewater. Withregardstoenvironmentalissues,the constructionwillinvolveminimalornoimpactstoreservoiroperations,waterqualityand quantity,recreationalandfisheriesresources,asalltheworkwillbeperformedontheterminal structure(downstreamside)oftheoutlet. Accessandsitepreparationwillsimplyinvolve closingthegateduringconstruction. TheareaaroundtheoutletandtheNorthDamOutlet Canalwouldbedryforthedurationoftheproject. AppendixAcontainspreliminarydesign plansforthenewterminalstructureanddrainsystem. TherehabilitationwillprovideasafeoutletstructureattheNorthDam,andwillcontrolseepage atthedam. Therepairsandimprovementswillenhancethelongevityofthedam,promote effectivewaterconservation,andgreatlyenhancepublicsafety. A404-permitapplicationhas beensubmittedtotheU.S.ArmyCorpsofEngineers. TheMontanaDepartmentofFish, Wildlife&ParkswasconsultedandindicatedthataMontanaDepartmentofEnvironmental QualityShort-TermExemptionfromSurfaceWaterQualityStandards(318)Permitanda MontanaStreamsideProtectionAct(124)Permitwouldnotberequired. TheDNRCDam SafetySectionhasbeeninformedoftheprojectintheeventaDamSafetyConstructionPermit isneeded. TheMontanaStateHistoricPreservationOfficeandtheMontanaNaturalHeritage Programhavealsobeencontactedconcerninghistoricresourcesandthepresenceofany speciesofspecialconcerninthevicinityoftheconstructionsite. Itisnotanticipatedthatany historicresourcesoranimalorplantspeciesofspecialconcernwouldbesignificantlyimpacted bytheproject. i