Fish, Wildlife and Recreation Mitigation Plan

Transcription

1 Chatfield Reservoir Reallocation Project Fish, Wildlife and Recreation Mitigation Plan Prepared for: The Colorado Parks and Wildlife Commission In accordance with C.R.S Prepared by: Chatfield Reservoir Reallocation Project Participants January 2014

2 TableofContents ExecutiveSummary 1.0 Introduction 1.1 PurposeofDocument 1.2 ProjectOverview 1.3 RegulatoryProcesses 1.4 Stakeholders 2.0 AvoidanceandMinimizationofAdverseImpacts 2.1 AvoidanceandMinimizationofAquaticandWildlifeEnvironmentalImpacts 2.2 AvoidanceandMinimizationofWetlandsandRecreationalImpacts 3.0 BenefitsoftheProject 4.0 MitigationofUnavoidableAdverseImpacts:FishandWildlife 4.1 ReservoirOperationsPlan General Definitions SpecificProvisions AdaptiveManagementforOperations 4.2 FisheriesandAquaticHabitat FisheryandAquaticHabitatintheSouthPlatteRiver Habitat and Recreation in the South Platte above Chatfield Reservoir Habitat and Recreation in the South Platte below Chatfield Reservoir FisheryandAquaticHabitatwithinChatfieldReservoir ChatfieldStateFishUnit AdaptiveManagementforAquaticLifeandFisheries 4.3 FluctuationZone FluctuationZoneMitigationMeasuresOverview PlumCreekRestoration NoxiousWeedControlPlan AdaptiveManagementforWeedControl ShorelineStabilizationPlan 4.4 WaterQuality WaterQualitywithinChatfieldReservoir WaterQualityintheSouthPlatteRiverbelowChatfieldReservoir AdaptiveManagementforWaterQuality 4.5 Wildlife,WetlandsandRiparianHabitat OverviewoftheCompensatoryMitigationPlan 1

3 4.5.2 CMPMitigationApproach SummaryofCMPMitigationMeasures AdaptiveManagementforWildlife,WetlandsandRiparianHabitat TreeManagementPlan AdaptiveManagementforTreeClearingwithintheFluctuationZone 5.0MitigationofUnavoidableAdverseImpacts:Recreation 5.1RecreationalFacilities 5.1.1RecreationalFacilitiesModificationPlan MarinaReplacementPlan HiringofTemporaryCPWResidentEngineer 5.2 FinancialPlan 6.0 Schedule 7.0 Conclusions References 2

4 Figures 1 ProjectAreaMap 2 ChatfieldProjectParticipants ServiceAreas 3 ReallocationAlternatives 4 PlumCreekExistingConditions(1) 5 PlumCreekExistingConditions(2) 6 PlumCreekConceptualStreamRestorationImprovements 7 ShorelineStabilizationPlan 8 Preble shabitatatchatfieldstatepark 9 BirdHabitatatChatfieldStatePark 10 WetlandHabitatatChatfieldStatePark 11 LocationsofProposedOnsiteMitigationAreas 12 LowerMarcyGulchPotentialOnsiteMitigationArea 13 SouthPlatteRiverPotentialOnsiteMitigationArea(1) 14 SouthPlatteRiverPotentialOnsiteMitigationArea(2) 15 SouthPlatteRiverPotentialOnsiteMitigationArea(3) 16 PlumCreekPotentialOnsiteMitigationArea(1) 17 PlumCreekPotentialOnsiteMitigationArea(2) 18 PlumCreekPotentialOnsiteMitigationArea(3) 19 AreasImpactedbyRecreationalFacilitiesRelocation,BorrowAreas,andHaulRoads 20 PotentialOffsiteMitigationAreas 21 SugarCreekOffsiteMitigationAreawithintheUpperSouthPlatte 22 PotentialPreble scriticalhabitatmitigationatsugarcreek 23 WestPlumCreekCriticalHabitatUnitforPreble s 24 Bird Habitat Complex Targeted for Cottonwood Regeneration and Mature Cottonwood Conservation 25 ChatfieldStateParkRecreationalAreas 26 ChatfieldMarinaExistingMarinaLocation(5,426 Elevation) 27 ChatfieldMarinaExistingMarinaLocation(5,440 Elevation) 28 ChatfieldMarinaExistingMarinaLocation(5,444 Elevation) 29 ChatfieldMarinaRoxboroughCoveMarinaLocation(5,426 Elevation) 30 ChatfieldMarinaRoxboroughCoveMarinaLocation(5,440 Elevation) 31 ChatfieldMarinaRoxboroughCoveMarinaLocation(5,444 Elevation) Tables 1ProposedMitigationsforProposedAction 2Acute(1day)lowflows(cfs)forthe10yearperiod1Oct1999through30Sep2000forthe SouthPlatteRiverbelowChatfieldDamtoMarcyGulch(fromAppendixJofFR/EIS) 3

5 Abbreviations AF AcreFeet(ameasureofwatervolumeequivalentto325,851gallons) BMP BestManagementPractice CDPHE ColoradoDepartmentofPublicHealthandEnvironment CDWR ColoradoDivisionofWaterResources cfs cubicfeetpersecond,ameasureofflowrate CHU Criticalhabitatunit(forPreble smeadowjumpingmouse) CMCC ChatfieldMarinaCoordinationCommittee CMP CompensatoryMitigationPlan CPW ColoradoParksandWildlife CRMC ChatfieldReallocationMitigationCompany C.R.S. ColoradoRevisedStatute CSFU ChatfieldStateFishUnit CWCB ColoradoWaterConservationBoard DNR ColoradoDepartmentofNaturalResources DWR ColoradoDivisionofWaterResources EDAW EDAW,Inc.,aconsultingrecreationalplanningfirm(nowAECOM) EFU EcologicalFunctionUnit EIS EnvironmentalImpactStatement ER EngineeringRegulation ERO EROResourcesCorporation,aconsultingenvironmentalplanningfirm ESA EndangeredSpeciesAct Fed.Reg. FederalRegister FEIS FinalEnvironmentalImpactStatement FR/EIS FeasibilityReport/EnvironmentalImpactStatement FWMP FishandWildlifeMitigationPlan msl meansealevel NEPA NationalEnvironmentalPolicyAct OHWM OrdinaryHighWaterMark PCT ProjectCoordinationTeam RFMP RecreationFacilitiesModificationPlan ROD RecordofDecision RSUA ReallocatedStorageUsersAgreement SWSI StateWaterSupplyInitiative,astudybytheCWCB TBD Tobedetermined USACE U.S.ArmyCorpsofEngineers USDA U.S.DepartmentofAgriculture USC U.S.Code USEPA U.S.EnvironmentalProtectionAgency USFS U.S.ForestService USFWS U.S.FishandWildlifeService WSA WaterStorageAgreement 4

6 ExecutiveSummary This Fish, Wildlife and Recreation Mitigation Plan has been prepared in response to the requirementsofc.r.s ItidentifiesactionsthattheChatfieldReservoirStorage Reallocation Project Participants will implement to mitigate unavoidable adverse impacts the Chatfield Reallocation Project will have on fish, wildlife, and recreation. (C.R.S does not require that a mitigation plan for recreation impacts be approved by the Colorado Parks and Wildlife Commission, however, significant efforts will be undertaken to mitigate unavoidable impacts to recreation facilities and amenities. These mitigations are included hereintoensurethatcoloradoparksandwildlifeconcernsarefullyaddressed). TheChatfieldReservoirStorageReallocationProject(Project)isaprojectwherebyagricultural andmunicipalwateruserswillusereallocatedspaceinanexistingfederalfacilitytodevelop newwatersupplies.chatfieldreservoirisa350,653acrefoot(af)reservoirsouthofdenver builtandoperatedbytheu.s.armycorpsofengineers(usace). The USACE currently allows 27,405 AF of water to be stored in Chatfield Reservoir for recreational,environmentalandwatersupplybenefits.theprojectwillreallocateanadditional 20,600AFoffloodspaceforwaterstoragetobenefitagriculturalandmunicipalwaterusersin the South Platte Basin resulting in up to 48,000 AF of storage space for recreational, environmentalandwatersupply. The Project began in 1996, when the Colorado Water Conservation Board (CWCB), as the Projectsponsoronbehalfof15waterproviders,formallyrequestedthattheUSACEconsider reallocating space within Chatfield Reservoir. This request was in response to a 1986 CongressionalauthorizationallowingtheUSACEtodeterminewhetheradditionalwatercould bestoredinthereservoirforwatersupplybenefitswhilenotcompromisingchatfield sflood controlfunction.theusacehasdeterminedthatupto20,600afofspacecanbereallocated withoutdiminishingthereservoir sfloodcontrolcapability.theprojectparticipantscurrently includeelevenmunicipalandagriculturalwaterusersandthecwcb. This Project will contribute to meeting a portion of the water supply needs of the Project Participants.Thereallocationof20,600acrefeetofstorageisestimatedtoresultinanaverage annual yield of 8,500 acrefeet of new water supplies. The CWCB Statewide Water Supply Initiative(SWSI)projectedthatColorado spopulationwillnearlydoubleby2050.thismeans thatthewatersupplyshortageinthesouthplattebasin(includingthedenvermetroarea),will beatleast100,000afperyearassumingthatpreviouslyidentifiedprojectssuchaschatfield Reallocationare100%successful.Totheextentthatidentifiedprojectsarenotallsuccessful, the gap in the South Platte and Metro basins could be as large as 360,000 AF per year. As shownintable12ofthefr/eis,thewatersupplyshortageforprojectparticipantsin2020is 119,200 AF with 85,000 AF of the shortage coming from agricultural participants. The 5

7 opportunitytouseanexistingreservoirtostorewateranddevelopnewsurfacewatersupplies partiallyaddressesthissignificantwatersupplyneed. TheFinalFR/EISidentifiesthereallocationof20,600AFastheTentativelyRecommendedPlan. TheFinalFR/EISwasmadeavailablefora90daypublicreviewfromJunethroughAugust,2012, andthefinalfr/eishasbeenmadeavailablefora30daypubliccommentperiodbeginningon August2,2013.TheRecordofDecisionisprojectedtobeissuedbylate2013orearly2014. The Project is located in Chatfield State Park, managed by the Colorado Parks and Wildlife (CPW). Environmental resources at Chatfield State Park will be negatively impacted by increased water storage in Chatfield Reservoir. Higher water levels will inundate some recreation facilities and environmental resources that have developed around the reservoir sinceitwasconstructed.inits38yearsofoperation,thereservoirgenerallyhasbeenmanaged to maintain waterlevels within a 9foot range (elevation 5,423 5,432 feet above mean sea level (msl)). The Project will result in an additional 12 feet of water level fluctuations. The ProjectwillalsoimpactenvironmentalresourcesaboveandbelowChatfieldReservoir.More detail regarding the actions to mitigate all identified adverse impacts are described in the FR/EIS. ThestorageofadditionalwaterinChatfieldReservoirisalsoexpectedtohavebeneficialeffects to the aquatic and wildlife environmental resources at or near Chatfield Reservoir. These beneficial effects will include improving the inreservoir fishery, enhancing raptor and bird habitatasaresultofanimprovedinreservoirfishery,enhancingthehabitatforshorelineavian speciesandflowaugmentationandprobabletemperaturereductioninthesouthplatteriver belowthereservoirfromsummerandfallwaterreleasesfromchatfieldreservoir.someofthe mitigation measures will provide additional benefits beyond accomplishing the targeted mitigations.forexample,improvinghabitatinsugarcreekforthepreble smeadowjumping mousewillhavetheadditionalbenefitofimprovinghabitatforthebrooktroutfisheryinsugar Creek(anoffsitemitigationsite). The Final FR/EIS identified what the USACE considers to be the Project s significant adverse impacts and the mitigations necessary to compensate for them. Project Participants will address additional environmental and recreational concerns identifiedby Colorado Parks and WildlifethroughtheadoptionandimplementationofthisStateFish,Wildlife,andRecreation Mitigation Plan. This plan is a compilation of, and includes by reference, the following documents: TheFinalFR/EIS TheCompensatoryMitigationPlan(CMP)(AppendixKoftheFinalFR/EISissuedon 6/8/2012), TheRecreationFacilitiesModificationPlan(RFMP)(AppendixMoftheFinalFR/EIS) ThenewMarinaMitigationPlanbeingdevelopedfromanongoingstudy, TheTreeManagementPlan(AppendixZoftheFinalFR/EIS), 6

8 TheUSACEAdaptiveManagementPlan(AppendixGGoftheFR/EIS),and ComparativeReviewofReservoirFluctuationZoneChatfieldReallocationProject (AppendixHHoftheFR/EIS) There are two key contracts currently being developed for the Project, The Water Storage Agreement (WSA) and the Reallocated Storage Users Agreement (RSUA). The WSA is a mechanismwherebytheusacegrantsthepermanentrighttostorageinchatfieldreservoirin exchangeforcommitmentstofulfillallfinancialandmitigationobligations.thewaterstorage Agreement establishes an oversight committee, called the Project Coordination Team (PCT), consistingofrepresentativesfromtheusace,stateofcoloradoandprojectparticipants.the PCT will oversee the implementation of all aspects of the project. The USACE has ultimate responsibilityforapprovalofprojectplansandthecompletionofmitigationrequirements. The Chatfield Water Providers are committed to responsibly avoiding, minimizing and mitigatingtheproject sidentifiedadverseimpacts.theadverseimpactstotheenvironmental andrecreationalresourcescausedbytheprojectandtheproposedmeasurestomitigatesuch impacts,includingcosts,aresummarizedinthefollowingtable1. 7

9 Table1:ChatfieldReallocationProjectFish,WildlifeandRecreationMitigationPlan(FWRMP) ProposedMitigationsforProposedAction RESOURCE IMPACT MITIGATIONS SECTIONOFFWRMPWHERE DISCUSSED ESTIMATEDCOST WILDLIFERESOURCES WithinChatfieldStatePark InReservoirAquatics FishWalleye DisruptionofWalleyeSpawnperiod March1April15 1)Participantscommittoensurereleasesdonotexceed420cfsduringMarch1April15period,understandingthat criticaltimeismarch )RegularcoordinationmeetingsbetweenParticipantsandCPWtoforecastupcomingoperationsclosecoordinationto minimizeadverseimpactfromreleases (B)(1) FishSmallmouthBass WaterQuality DisruptionofSmallmouthBassspawn periodjune1june30 Increaseinphosphateandammonia loading; DecreasedDissolvedOxygen; Increasedmercurymethylationfrom anoxicorincreaseddissolvedoxygenin thereservoir MitigationdealtwithinoperationsagreementsParticipantscommittolimitreleasesMay1July15waterdeclinewillnot begreaterthan8000aft,july16aug31waterleveldeclinenotgreaterthan4000aft,may1aug31collectivedaily dischargeshallnotexceed420cfs 1)ParticipantsagreetowaterqualitymonitoringandmodelingprogramincoordinationwithChatfieldWatershed Authority. 2)WetlandcreationandhabitatimprovementsonPlumCreekintheCMP. 3)PlumCreekriparianrestoration (B)(2) 4.4.1;4.5;4.3.2 $1,300,000(est.)forwater qualitymonitoringand modeling,$6,088,600for PlumCreekrestoration Terrestrialwildlife Preble'sMousePlum CreekCriticalHabitat Preble'sMouseSouth PlatteCriticalHabitat 75acresofcriticalhabitat/65EFU's 80acres/2.8miles 1)FromCMP:Onsite:6acres/3EFUshabitatcreation. 2)FromCMP:Offsite:unknownacresprivatelandprotectionandenhancement/62EFU'sneeded. 1)FromCMP:Onsite:17acreshabitatcreation; 2)Offsite:73acresprivatelandprotectionandenhancement.ChatfieldResMitigationCompanywillcoordinatewCPWin thedevelopmentofthisprocess; 3)4.5milesand381acresofSugarCreekimprovements 4.5 $58,500,000forCMP 4.5 Preble'sMouseNon CriticalHabitat 298acres/210EFUs 1)FromCMP:Onsite:111acresofhabitatcreation/43EFUs. 2)FromCMP:Offsite:unknownacresprivatelandprotectionandenhancement/167EFU'sneeded 4.5 Otherterrestrialwildlife andbirds 586acres(inundationzone)/377EFUs 1)FromCMP:Onsite:165acreshabitatcreationandenhancement/9birdEFU's. 2)PlumCreekRestorationPlan; 3)Treemitigationplanwilladdressimpactsaswell. 4)FromCMP:Offsite:unknownacres/368EFU'sneeded. 4.5;4.3.2 Amphibians/Reptiles Erosionoflandarea /habitat Groupedinto Preble s/wetlands/terrestrial Sedimenterosionduetonewstorage andwaterfluctuation MitigationactionscoveredunderPreble s/wetlands/terrestrialresources 4.5 1)Bankstabilization/Erosioncontrol/PlumCreekerosionandstreamerosion 4.3.4;4.3.2 $716,100forshoreline stabilizationplan CMP 8

10 MatureCottonwoodsand othercottonwoods 42.5acres 1)13acresnewcottonwoodgenerationonsite(inCMP). 2)22.5acresprotectionofexistingoffsitehabitat(inCMP). 3)10acresnewcottonwoodgenerationoffsite(inCMP). 4)Recreationmodificationplanwillmitigateforadditionalcottonwoods. 5)Treemanagementplan. 6)Resoperationsplanwaterlevelinsummer ;5.1.1;4.5.5; Wetlands upto159acres/123efu's 1)InCMP:Onsite:47acres/30EFUs. 2)InCMP:Offsite:Unknownacres/93EFU's InvasiveSpecies/Weeds Increasedinvasives 1)BMPstocontrolspread(inCMP). 2)Monitoringandtreatmentofnoxiousweedsinprojectarea(greaterthan400ft) 3)Weedmonitoringandweedcontrolfor5yearsinrevegetation/mitigationsites(inCMPandAMP). 4)Weedcontrolinfluctuationzoneisongoingobligation(inCMP) DOWNSTREAMOFCHATFIELDSTATEPARK AquaticResources Downstreamaquatic habitat AquaticHabitatwater quality Decreasedstreamflowimpacton aquatichabitat; Increasedlowflows/zeroflowdays IncreaseE.colifromreducedflows; Increasetemperaturefromreduced flows 1)0.5miofstreamhabitatimprovement(ChatfieldDamtoMarcyGulch),potentialuseofCPWwaterrightstocreatean environmentalpooltomitigatelowflowdays. 2)Besteffortstotargetreleasestolimitzeroflowdaysandmitigatewithenvironmentalpool. 3)Potentialdevelopmentofenvironmentalpoolfortargetreleases(firstgoal)and/orenvironmentalflowreleases. 4)Requiredreleasesforcriticallowflows. 1)Waterqualitymonitoringprogrambelowdam. 2)Besteffortstotargetreleasestolimitzeroflowdays(inoperationsplanaddcitation). 3)Requiredreleasesforcriticallowflows. 4)Potentialdevelopmentofenvironmentalpoolfortargetreleasesand/orenvironmentalflowreleases. ChatfieldStateFishUnit Decreasedflows AgreenottoexerciserightsseniortothehatcheryifwouldcausecurtailmentofCSFUrights(onlyifhistoricflowswould havepassedbycsfu) ; (D) 4.4.2; (D) (A);4.2.3 Increaseinzeroflowdays Potentialdevelopmentofenvironmentalpooland/orenvironmentalflowreleases UPSTREAMOFCHATFIELDSTATEPARK Aquatichabitat Inundationofupstreamfishhabitat Permanenthabitatconversionfrom sedimentdeposition; Lossofstreamchannelfornativefish frominundationimpactsonplumcreek 1)Fundhabitatimprovementfor0.7milesupstream. 2)PlumCreedRestorationplan. 3)WetlandsimprovementsinCMPmightmitigateintermittentstreammileage. 4)SugarCreekImprovements ;4.5.3;4.3.2 RECREATIONALRESOURCES WITHINCHATFIELDSTATEPARK FacilitiesandRecreational Use Lossoffacilitiesduetoinundation. 1)RMPdetailsmitigationmeasuresforfacilitiesandrecreationalusesincludescontingencyapproachthatgivestheplan flexibility. 2)NewtemporaryCPWengineeringemployeehiredduringdesignandconstructionofrecreationalfacilities 5.1.1;5.1.3 $265,000for.5mile streamenhancement $369,600for.7mile streamenhancement $31,600,000for recreationalfacilities modificationplan, $225,000(est.)for temporaryresident engineer Marinaunusableduetoinundation ChatfieldMarinaCoordinationCommittee(CMCC)workingonseparatemitigationplanforthemarina $15,700,000 9

11 Lossofwildlifeviewingandshade 1)CMP&TreeManagementPlansdetailmitigationforwildlifeviewingandshadePlumCreekrestoration(ifapproved) wouldaddressaccesstoviewingopportunities. 2)13acresofonsitemitigation(formaturecottonwoods). 3)32.5acresofoffsitemitigation. 4)Treemanagementplanmodifiedtoleavetreesdownto5432anduseofadaptivemanagementtoremovedeadordying treeswithinthefluctuationzone ;4.5.5;4.3.2 Facilityvulnerabilitytofutureflooding Couldbeaddressedinthedesignphasetoraisetheroadsbyswimbeach,balloonareaandDeerCreektomakeroadsstill abletohandle10yearfloods QualityofRecreationalExperiences 1)Restrictreleasesto8,000ac/fttotalfromMay1July15thand12,000totaltoAugust31st. 2)Fluctuationzonemitigationsthatincludes:vegetationandweedcontrol,newcottonwoodregenerationalongshoreline andfacilities,shorelinestabilizationplan,plumcreekimprovements. IncreasedBoatingHazards Fundingofcontractlaborandequipmentforhazardremoval,signing,operationalimpactsduetoincreasedinundationand fluctuations.operationalissueswillbecoveredinthefinancialmitigationplan. WaterQualityraisedelevationcauses erosionwhichwillaffectaccessbelow campground ;4.3.3;4.5.3;4.3.4; )Monitoringandmodelingofwaterquality.2)PlumCreekrestorationplan 4.4.1;4.3.2 PublicUnderstanding 1)ProjectParticipantshaveagreedtoamarketingplantobeimplementedpriortoconstructionandcontinuingafter constructioniscompletepartoffinancialmitigationplan,whenapproved. Streamfishing Streamfishing ReducedRecreationalOpportunities reducedfishingfromadditionalzeroor lowflowdays ReducedRecreationalOpportunities reducedfishingfromintermittent inundation 1)Establishanenvironmentalpooltomitigatelowflowdaysuseofhatchery,downstreamuses. 2)Mitigationof0.5miofstreamhabitatimprovement 3)Operationsplanlanguageofgoodfaitheffortstostrategicreleases. 1)0.7miofstreamhabitatimprovements. 2)SugarCreekimprovements 5.2 $200, ; (D) ;4.5.3 RevenueandOperatingExpenses ParkRevenue Decreasedrevenuesduring constructionandpostconstruction 1)FinancialMitigationplan. 2)WPtocoverlostrevenue 5.2 $1,000,000(est.)for financialplan ParkOperating Increasedoperatingexpenses WPtocoverincreasedoperatingcostsattributabletoproject 5.2 EstimatedCostTotals Costsformitigations requiredbytheusace Additionalcostsfor FWRMPmitigations $107,100,000 $8,864,300 TotalMitigationCosts $115,964,300 10

12 1.0Introduction 1.1PurposeofDocument This Fish, Wildlife and Recreation Mitigation Plan (Mitigation Plan) has been prepared in response to the requirements of C.R.S and identifies actions that the Project Participants will implement to mitigate the unavoidable adverse impacts that the Chatfield Reallocation Project will have on fish, wildlife, and recreation. The Colorado Statute requires that fish and wildlife resources that are affected by the construction, operation or maintenanceofwaterdiversion,deliveryorstoragefacilitiesshouldbemitigatedtotheextent, and in a manner, that is economically reasonable and maintains a balance between the developmentofthestate swaterresourcesandtheprotectionofthestate sfishandwildlife resources andthat impactson[fishandwildlife]resourcesshouldbemitigatedbytheproject applicantsinareasonablemanner. This Mitigation Plan includes mitigation for recreation impacts and represents the complete mitigationpackageaddressingcpwconcerns. 1.2ProjectOverview The proposed Chatfield Reallocation Project increases thebeneficial components of Chatfield Reservoirbyreallocatingstoragespacetofacilitatenewwatersupplydevelopment. ChatfieldReservoirandChatfieldStatePark Chatfield Reservoir is located within Chatfield State Park, southwest of Denver at the confluence of the South Platte River and Plum Creek (Figure 1). The reservoir, owned and operated by the USACE, was completed in 1975 to provide flood protection for the metropolitandenverareafollowingthedisastroussouthplatteriverfloodof1965. ChatfieldReservoirhasamaximumcapacityof350,653acrefeet(AF).Upto27,405AFmay currentlybestoredforrecreationalandwatersupplypurposes.denverwateriscurrentlythe only water user storing water in Chatfield Reservoir. In general the reservoir has been managedtomaintainwaterlevelswithina9footrange(elevation5,423to5,432feetabove meansealevel(msl)).theaveragerangeofmeanmonthlyelevationshasbeenapproximately 3 feet from low to high reservoir periods. The current Ordinary High Water Mark (OHWM) elevationis5,432feetabovemsl. Colorado Parks and Wildlife (CPW) manages recreation at Chatfield Reservoir and Chatfield StatePark.ChatfieldStateParkcoversabout5,300acres,1,500acresofwhichincludeChatfield Reservoir. The Park annually receives about 1.6 million visitor days, generating about $2.2 million in revenues that support operations and maintenance of Chatfield State Park and contributetofundingthestateparksystem. 11

13 Chatfield Reservoir is one of three walleye brood lakes statewide, providing up to 33 million walleyeeggsforstockingincoloradowatersstatewide.thesouthplatteriveraboveandbelow thereservoirisutilizedbyanglersonayearroundbasisand,givenitscloseproximitytothe DenverMetroarea,isparticularlyvaluablebecauseitprovidesanopportunitytofishcloseto home. CPWownsandoperatesafishdistributionhatcheryunit,locatedbelowthedamthatplaysa criticalroleinenablingcpwtostockvariousfrontrangewatersinthespringandsummer.this unit is intended to function as a fully operational hatchery but does not due to water availabilitylimitations. HistoryoftheChatfieldReservoirStorageReallocationProject In 1986, in Section 808 of the Water Resources Development Act, Congress authorized the USACEtoconductareallocationstudyforjointfloodriskmanagementconservationpurposes, including whether storage for municipal and industrial water supply, agriculture, recreation, andfisheryhabitatprotectionandenhancementcouldbeaccomplishedwithoutrisktoflood control.theauthorizationrequiredthatthecoloradodepartmentofnaturalresources(dnr) be the local sponsor for the reallocation and that the Chief of Engineers conclude the reallocationisfeasibleandeconomicallyjustified. In 1996, on behalf of 15 water providers, the Colorado Water Conservation Board (CWCB) formally requested that the USACE consider reallocating space within Chatfield Reservoir for watersupplypurposes. In1999,aFeasibilityReportandEnvironmentalImpactStatement(FR/EIS)processwasinitiated toconducttheanalysesrequiredbythechiefofengineers findings(er ,ch.4).the overallfr/eisstudyareaencompassestheareaintheimmediatevicinityofchatfieldreservoir andextendsdownstreamtowheretheriverintersectstheadams/weldcountyline(figure1). TheFR/EISusedtheCWCB sswsi,andotherrelevantplanningstudies,toidentifyalternatives for reallocation. A total of 37 concepts were evaluated in the initial screening process. The developmentofalternativestoreallocationandthescreeningprocessaredescribedindetailin Chapter 2 of the FR/EIS. The FR/EIS evaluates, in detail, the environmental, social, and economiceffectsoftheproposedrecommendedalternative,aswellastwootheralternatives andanoactionalternative. Thealternativereallocating20,600AFofstoragespaceinChatfieldReservoirisboththelocally preferred plan and the USACE s Tentatively Recommended Plan (hereinafter referred to as the Chatfield Project). The average annual water yield from the Recommended Plan is estimatedat8,500af.thisprovidesapartialsolutionfortheestimated360,000afperyear (year2050)gapinwatersupplyforthefrontrangeidentifiedintheswsistudy.totheextent thatidentifiedprojectssuchaschatfieldreallocationare100%successful,theremaining2050 gapisstillestimatedtoberoughly100,000afperyear.asshownintable12ofthefr/eis, the water supply shortage for project participants in 2020 is 119,200 AF with 85,000 AF the shortagecomingfromagriculturalparticipants. 12

14 TheFinalFR/EISwasmadeavailablefora90daypublicreviewfromJunethroughAugust,2012, and the Final FR/EIS is scheduled for completion by September 30, The Record of Decisionisprojectedtobeissuedbylate2013orearly2014. TheChatfieldProjectParticipantsandtheirshareofthereallocatedstoragespace(Reallocation Space)aregivenbelow.TheParticipants serviceareasareshowninfigure2. Storage %oftotal Amount,AF 1 CentralColo.WaterConservancyDist. 2, % 2 WesternMutualDitchCompany 1, % 3 DenverBotanicGardensatChatfield % 4 CentennialWaterandSanitationDist. 6, % 5 CastleRock 1, % 6 CastlePinesNorthMetroDist % 7 CastlePinesMetroDist % 8 SouthMetroWaterSupplyAuthority 1, % 9 MountCarbonMetroDist % 10 CenterofColoradoWCD % 11 ColoradoWaterConservationBoard 5,161.00* 25.05% 20, *Note:CWCBstorageamountsubjecttochangependingtransferswithotherentities Upon final approval of the Project, the Participants will be responsible for the operation, maintenance,andrepairofinfrastructure,treatment,anddistributionfacilitiesassociatedwith their water and their share of the Project rehabilitation and replacement costs. The Participants would fully fund the environmental mitigation and recreation modifications necessarytomitigatetheimpactsofoperatingthereservoirunderthestoragereallocation.the CPWwillbeintegralintheimplementationofthemitigationandwillbeabletoensurethesite specific plans for onsite mitigation are acceptable and consistent with its management of ChatfieldStateParkresources. 1.3RegulatoryProcesses TheProjecthasundergonesignificantregulatoryscrutinyatthefederal,stateandlocallevels. At the federal level, USACE performed extensive and detailed project feasibility and environmentalstudiespursuanttoitsregulatoryandplanningrequirements.theculmination oftheprocessisajointfeasibilityreport/environmentalimpactstatementthatwillserveas thebasisforissuanceofthedepartmentofthearmyrecordofdecision(rod). The following federal, state and local regulatory approvals are required to implement the Project: 13

15 Federal:CompliancewithSection404oftheCleanWaterAct(CWA)fordredgeandfill activities in waters of the U. S. associated with the recreational facilities modification planandothermitigationincidenttothereallocation;compliancewithsection7ofthe EndangeredSpeciesAct(ESA)relatedtoimpactstoPreble smouseanditsdesignated critical habitat; and U.S. Forest Service(USFS) approval for work on USFS land (along SugarCreek). State: Approval by CPW Commission and the Colorado Water Conservation Board of this Fish, Wildlife, and Recreation Mitigation Plan pursuant to C.R.S ; ColoradoDepartmentofPublicHealthandEnvironment(CDPHE)constructionpermits forairquality,waterqualitycertificationforanydischargerelatedmitigationactivities, andpermitsforstormwaterandconstructiondewatering. Local:DouglasCountypermitsforconstructionworkalongSugarCreekandatChatfield Reservoir;andJeffersonCountypermitsforconstructionworkatChatfieldReservoir. 1.4Stakeholders Thestakeholderentitiesinclude: Federal:USACE,USEPA,USFS,andUSFWS; State:DNR,CWCB,CPW,DWRandCDPHE; Local:(InadditiontotheProjectParticipants)DenverWater,CityofLittleton,South SuburbanParksandRecreationDistrict,CityandCountyofDenver,DouglasCounty Commissioners, Jefferson County Commissioners, Weld County Commissioners, MetroWastewaterReclamationDistrict,ChatfieldWatershedAuthority,andUrban DrainageandFloodControlDistrict;and Nongovernmental organizations: The Greenway Foundation, Audubon Society of GreaterDenver,ColoradoEnvironmentalCoalition,SierraClub,WesternResources Advocates,TroutUnlimited,ChatfieldBasinConservationNetwork,andTheNature Conservancy. TheProjectParticipantshaveconsultedandconferredwithabroadrangeoffederal,state,local andenvironmentalstakeholderstosolicitinputonappropriatemitigationofadverseimpacts associatedwiththeproject.publicparticipationeffortsincludednoticesandpublicmeetingsto meet NEPA requirements during the release and review of the Final FR/EIS. Meetings with stakeholderentitiesstartedin1994andcontinuedwithregularlyscheduled,usuallymonthly, meetingshostedbythecoloradowaterconservationboard. 14

16 2.0 AvoidanceandMinimizationofAdverseImpacts Throughouttheprocess,theProjectParticipantssoughtanenvironmentallyresponsibleproject by,first,seekingtoavoidadverseimpactstoaquaticandwildliferesourceswheneverpossible; second,minimizingunavoidableadverseimpacts;andfinally,developingmitigationmeasures tofullycompensatefortheremainingadverseimpactsoftheproject.belowarechangestothe original Proposed Action made to avoid and minimize adverse impacts associated with the Project: 2.1AvoidanceandMinimizationofAquaticandWildlifeEnvironmentalImpacts Actionstoavoidorminimizeadverseaquaticandwildlifeenvironmentalimpacts: IncorporationofBestManagementPracticestoclearlandtobeinundatedofvegetationto minimizethenutrientloadingintothereservoir. Agreement on timing and operational limitations on releases of stored water to avoid adverseimpacttothewalleyeeggcollection,otherfisheryoperations,recreationandtrees. Developmentofacoordinatedoperationsplantominimizewaterlevelfluctuationsduring criticalrecreationandfisheryoperations. Theuseofadaptivemanagementapproachestominimizeadverseimpactsasmanagement knowledgeisgainedfromprojectimplementation.adaptivemanagementresponseswillbe applied to water quality, vegetation, wildlife, wetlands, and threatened and endangered species. 2.2AvoidanceandMinimizationofWetlandsandRecreationalImpacts InordertomaintaintherecreationexperienceofChatfieldStatePark,recreationinfrastructure mustberelocated.thepreliminaryrecreationfacilitiesrelocationplanwaspresentedtothe USACEDenverRegulatoryOfficetodiscuss404permittingimplicationsandhowthedischarge of fill material into waters of the U. S. could be avoided or the effects minimized. Each recreation related facility was reviewed and evaluated to determine if it could be located or constructedinawaytoavoidorminimizethedischargeoffillmaterialintowetlandsandother potentialimpactstowetlandsandsensitiveresourceareas.whileitisfeasibletoaccomplish these activities without a discharge, the desired approach for modification of recreation facilitieswillinvolvesomedischargeofmaterial. ComponentsoftheRecreationFacilitiesModificationPlanrevisedtominimizethedischargeof dredgeorfillmaterialintowetlandsandpreserveuniquerecreationalamenitiesinclude: Gravel Pond Area. The plan includes the rebuilding of the dike north of the gravel pond withanewparkroadontop,inthesamelocationastheexistingroad,inordertominimize impactstothesurroundingareaaswellastopreservethegravelpond.thesideslopesof 15

17 theroad/dikeweresteepenedandtheroadwasrealignedtofurtherreducethefillingof wetlands.theroadontheeastsideofthegravelpondwasrealignedtocompletelyavoid thedischargeoffillmaterialintowetlandsand,topreservethegravelpondfrominundation at5,444abovemsl,willincludeanewdikeatanadditionalcostofapproximately$500,000. These actions preserve the highly valued and relatively rare recreational experiences of scuba diving, long distance swimming, canoeing and kayaking (without the influence of nearbypowerboats)atchatfield. North Boat Ramps. The extension of the north boat ramps was revised to minimize the dischargeoffillmaterialbelowtheohwm.earlyconceptualalternativesforthisareawere replacedwithamoreextensiveplaninvolvingreconstructionoftheparkinglot,entryroad, andboatrampsinordertominimizeexcavationbelow5,432feetabovemslandtoavoid impactstowetlands. Swim Beach. Alternative configurations of the beach and causeway were analyzed to ultimatelydevelopanapproachthatminimizestheamountofwetlandsfilled. Catfish Flats. The Catfish Flats recreation area was redesigned to avoid any discharge of dredgeorfillmaterialintowatersoftheu.s.,includingwetlands. MarinaArea.Thebreakwatersofthemarinawererevisedtoreducetheirfootprintandthe amountofcutandfillbelowtheohwm.substantialmodificationsofthisareaweremade, includingrelocationoftheentryroad,parkinglotandfacilities,andthereconfigurationof thebreakwater. PlumCreekArea.TherelocationofthePlumCreekTrailwentthroughseveraliterationsto minimizethedischargeoffillintowetlands. 3.0 BenefitsoftheProject WaterSupplyBenefits: Approximately8,500AFaverageyearyieldofnewrenewablesurfacewatersupplies are developed from this expanded use of an existing reservoir. These new water supplies benefit water users from Park County, to Douglas County, and to Weld County. 20,600 AF of new, on channel storage space is developed at a location high in the SouthPlattebasin. EnvironmentalandRecreationalBenefits: Apotentiallyimprovedinlakefishery: 16

18 o o o New Reservoir effect of additional water, when available, may result in increased primary productivity within the reservoir and a resulting positive benefittofoodchainproductioninvirtuallyalltrophiclevels; Positive impact to gizzard shad and other forage fish during increased pool elevations,exceptduringmidmaytomidjune;and Benefit to crayfish populations from increased shallow water areas with a resulting enhancement of forage for smallmouth and largemouth bass populations. Newrecreationalandinfrastructurefacilitiesbuilttocurrentcodes. Additionalwaterprovidesadditionalboating,canoeingorkayakingopportunities. Potentialbenefitstoshorelinewildlife: o Increasedexposureofshorelinesmaybenefitmigratingpipingplovers;and o Increasedshorelineareasbenefitleastterns,ducks,geeseandotherwaterbirds andshorelinebirdspecies. Potentialbenefitstootherbirdspeciesfromenhancedfisheryorotherfactors: o Increasedfoodsupplyforbaldeagleandotherraptors; o Increasedfisheryfoodsupplyforwhitepelicanandotherbirdspecies;and o Assometreesintheinundationareaareleftstanding,heronsandcormorants will benefit from the creation of a more secluded area of trees surrounded by water,providingnewnestinghabitat;cavitynestingbirdswillbenefit. Keeping fallen trees as anchored fish structures would create positive shallow water habitat,solongastheyareappropriatelymarkedtopreventbeingboatinghazards. Water that is released from Chatfield Reservoir during mid to late summer and throughout the fall and winter, to convey that water to downstream users, would improve the downstream fishery by increasing flow rates and possibly lowering otherwisehigherwatertemperatures. NewwetlandswillbecreatedasmitigationfortheProject.Thesewetlands,alongwith mitigating the loss of other wetlands, are expected to improve upon current water qualityconditionsinthesouthplatteriverandplumcreek. ImprovementstoPlumCreektorepairseriousexistingdegradationandprovidesome degreeofchannelstabilizationwillalsoenhanceorimprovewaterquality,restore wildlifehabitatandmayimprovethefishery. The Sugar Creek Mitigation project, designed to preserve and enhance the Preble s MeadowJumpingMousehabitatadjacenttoSugarCreek,willprovideancillarybenefits tothebrooktroutfisheryinsugarcreekfromreducedsedimentation. 17

19 4.0 Mitigation of Unavoidable Adverse Impacts: Fish andwildlife Thestorageofupto20,600additionalAFofwaterintheChatfieldReservoirwillperiodically inundaterecreationinfrastructureandenvironmentalresourcesandmayresultinanadditional 12feetofpotentialwaterlevelfluctuations(Figure3).Thefollowingmeasuresaddressimpacts tofisheriesandaquatichabitat,wetlandandriparianhabitat,recreationandwildlifehabitat. 4.1ReservoirOperationsPlan TheintentoftheReservoirOperationsPlanistoensureclosecommunicationsbetweenCPW and the Project Participants regarding reservoir operations and to coordinate operations to lessenimpactsfromtheproject.theplanincludesspecificcommitmentsdesignedtominimize thepotentialforadverseimpactsoncertainspecies,habitatandrecreation General Uncertainty: Reservoir operations are inherently uncertain due to a variety of factors (fluctuating demands, change in water usage, randomness and high variability of natural phenomena, climate change, extreme events, operational variability, and maintenance). The purpose of the Reservoir Operations Plan is to attempt to lessen the uncertainty associated withthesefactors. YieldandUsefulnessoftheWaterfromuseofthestoragespace:Subjecttothecommitments madeinsection below,cpwwillnotseekanyoperationthatwouldresultinareduction of the water right yield or significantly impair the usefulness of the storage space to each ProjectParticipant. OperationsPlanonlypertainstowaterstoredbytheProjectParticipants:Theprovisionsofthis plan do not change the April 3, 1979 agreement between Denver Water and the State of ColoradoDepartmentofNaturalResourcesrelatedtostorageinChatfield Definitions: Parties:CPWandtheProjectParticipants Fluctuations:Waterbeingstoredandreleasedsoastocausethereservoirleveltogoupand down. 18

20 GoodFaithEfforts:WherebyallPartiesworktogethertouseeconomicallyreasonablemethods and means to achieve certain goals while maintaining a mutual understanding that in some situations,suchasdrought,prolongedperiodsofbelowaveragewateryears,actsofgod, or othercircumstancesbeyondthecontrolofthechatfieldparticipants,thesegoalsmaynotbe fullyattained SpecificProvisions: Meetings PartieswillmeetbimonthlyFebruarythroughOctoberofeachyeartosharetheirknowledge ofcurrentconditionsanddiscussforecastsforfuturechatfieldoperations. At the meetings, the Parties will review current conditions and forecasts; discuss operational strategies and expected diversions into and deliveries from storage and include fish health informationtoassistinprotectingfishandtheirhabitat. Sources to be used for forecast information may include NOAA, National Weather Service ClimatePredictionCenter,ColoradoClimateCenterPrecipitationMonitoring,NRCS,theState EngineersOffice,currentoperatingconditionsofeachparticipant,DenverWater,andothers,as determinedbytheparties. Theentitiesattendingthemeetings,thefrequencyanddatesofmeetingsmaybechangedby mutualconsentoftheparties WaterStorage ChatfieldReallocationProjectParticipantsmaystoreanylegallystorablewaterinChatfieldthey areentitledtoatanytime WaterReleases A. Ingeneral,ProjectParticipants,inconsultationwithCPW,willusegoodfaitheffortsto adjust the timing and amount of water releases from Chatfield so as to beneficially impactrecreationandtheenvironment.uponrequestofcpw,waterreleasestothe South Platte River from Participants storage accounts will be made through the Chatfield State Fish Unit, so long as the water released can be appropriately administeredbythestateanddivisionengineersandcreatesnoinjurytootherwater rights.cpwwillbesolelyresponsibleforreplacingintime,locationandamountanyout ofprioritydepletionscausedbytheprojectparticipants waterbeingroutedthroughthe ChatfieldStateFishUnit. B. 1.From March 1 to April 15, to avoid impacts to walleye spawning, Participants committolimitthedecreaseinthereservoirwaterlevelelevationfromtheparticipants 19

21 storageaccountstonomorethan6 perday(whichisequivalenttonomorethan420 cfsofoutflowinexcessofinflow).theparticipantsdonotanticipatethat,undernormal circumstances,theirreleaseswillcausearapidlydecreasingpool.thepartiesrecognize thattheonlytimeduringtheperiodfrommarch1toapril15thatreleaseswouldbe greaterthan6 perdayislikelyduringafloodeventorinanticipationofafloodevent. In such instances, Project Participants are not responsible for decreases in elevation greaterthan6.atalltimes,projectparticipantsareonlyresponsibleforreleasesthat occurasaresultoftheiruseoftheirstoredwater. 2.Toavoidimpactsonsmallmouthbassspawning,Participantswillconsultwith CPW on operational actions to minimize adverse impacts to smallmouth bass propagation. C. Participantswilllimitreleasesfromthereallocatedprojectstoragespace,asaccounted for by the Division of Water Resources and recorded on the Chatfield Storage AccountingSheet,suchthat: 1. BetweenMay1andJuly15,thewaterleveldeclineofthatspaceattributedto Participantreleasesisnotgreaterthan8,000AF; 2. BetweenJuly16andAugust31,thewaterleveldeclineattributedtoParticipant releaseswillnotexceed4,000af;and, 3. DuringtheperiodofMay1toAugust31,thecollectivedailydischargefromthe reservoirfromthechatfieldparticipantsshallnotexceed420cfsofoutflowinexcessof inflow. However,thecommitmentsundertheabovethreeprovisionsmaybesuspendedforthe remainderofacalendaryearifthefollowingtwoconditionsaremet: 1. At any time during the calendar year prior to August 31 the United States DroughtMonitorindicatesthata severedrought (alsoknownasad2severedrought) existsforfourconsecutiveweeksanywherewithintheparticipantssourcewatersheds orserviceareas. 2. Participants who provide a municipal water supply impose some measure of wateringrestrictionsoncustomerswithintheirserviceareas. ItisexpectedthatthePartieswillusethebimonthlyoperationalmeetingsdescribedin Section toforecastwhethertheaboveconditionsarelikelyoccurinagivenyear andusegoodfaitheffortstominimizeenvironmentalandrecreationalimpactsdueto thesuspensionoftheseoperationalcommitments. D. BetweenJuly15andthefollowingMay1,solongasParticipantswillnotloseyieldand are reasonably able to make use of a release of water from storage, Participants will make good faith efforts to work with CPW to time the releases out of Chatfield in a manner that would benefit the fishery and riparian environment downstream of Chatfielddam. 20

22 Thisplanmaybechangedfromtimetotimeonlybymutualagreementoftheparties AdaptiveManagementforOperations Adaptive management uses iterative decisionmaking to adjust compensatory mitigation to meetthecoreobjectives.resultsareevaluatedandfutureactionsareadjustedonthebasisof whathasbeenlearned.boththefish,wildlifeandrecreationmitigationplanandthefr/eis recognizethatadjustmentsmayneedtobemadeasthemitigationactivitiesinthoseplansare implemented. The details of the adaptive management required by the USACE are in the document entitled Adaptive Management Plan, which is Appendix GG of the FR/EIS. That documentdescribesthecoreobjectives,uncertaintiesandcontingenciesforeachoftheareas ofwaterquality,reservoiroperations,weedcontrol,treeclearing,aquaticlifeandfisheries,and thesubjectofthecmp,thetargetenvironmentalresources. In addition to unanticipated issues and challenges, the following are examples of what could requireadjustmentsinthefish,wildlifeandrecreationmitigationplanascurrentlyproposed: Allofthemitigationmeasuresmaynotbecompletelysuccessful; Somemitigationactivitiesmayprovidemorebenefitthancurrentlyestimated; Otheropportunitiesmaybecomeavailabletoprovidemitigation;and Natural disasters, such as forest fires or floods, could adversely affect mitigation activities. Bytheirverynature,adaptivemanagementactionsareimplementedonan asneeded basis and as informed by monitoring. The monitoring of impacts and mitigation will provide important information and feedback for an iterative process of refining action to minimize impacts and address uncertainties. Annual monitoring reports will include information on neededandproposedadjustmentsanduncertainties.monitoringwillbeconcludedwhenallof thecoremitigationobjectivesaremet,whichwillultimatelybedecidedbytheusace. Thecoreobjectivesforoperationsare: 1. Determineatargetelevationrangeandseasonalscheduleofstorageandreleasesthat wouldminimizeadverseeffectsonthetargetenvironmentalresourcesandrecreation; 2. Determineoperationsthatcouldmeetthetargetelevationandseasonalscheduleof storageandreleasesona besteffort basiswithoutadverselyaffectingtheyieldofthe ChatfieldWaterProvidersasidentifiedinthisreallocationproject; 3. Annuallymonitortheeffectsofstorageinthereallocatedspaceonthetarget environmentalresources; 4. Continuetoexplorewaystoadjustoperationsascircumstancesallowminimizing adverseeffectsonthetargetenvironmentalresourcesandrecreation;and 21

23 5. ProvidefeedbackandrevisionsasneededtotheCMPregardingtheneedformoreor lessmitigationbasedonoperationofthereallocatedstorage. TheAdaptiveManagementPlan,AppendixGGoftheFR/EIS,givesfurtherdetails. 4.2FisheriesandAquaticHabitat 4.2.1FisheriesandAquaticHabitatintheSouthPlatteRiver HabitatandRecreationintheSouthPlatteaboveChatfieldReservoir ImpactThe Project will cause fishery and aquatic habitat to be negatively impacted by inundatingupto0.7milesupstreamofchatfieldreservoironthesouthplatteriverandplum Creek.ThissectionoftheSouthPlatteRiverisacoldwatertroutfisheryusedforrecreational fishing. MitigationTheProjectParticipantswillfundstreamhabitatimprovementsonupto0.7miles ofthemainstemofthesouthplatteriverabovechatfieldreservoirabovethehighestpointof potentialinundationfromtheproject.thepurposeofthehabitatimprovementsistoimprove thecoldwatertroutfishery.thespecificsiteandprojectdesignwillbedoneatthedirectionof thecpwatacostofupto$100perlinearfoot(atotalof$369,600forthisproject),whichthe ParticipantsandCPWhavedeterminedisadequatetoaccomplishthenecessarystreamhabitat improvements. The habitat improvement work will be targeted to be completed within five yearsofissuanceoftherecordofdecisionandbeforetheinitiationofstorageofwaterinthe reallocatedstoragespace. Inaddition,aspartoftheCompensatoryMitigationPlan,theParticipantswillimplementthe Sugar Creek Sediment Mitigation Project to substantially reduce sediment inputs into the approximately4.5milereachofsugarcreek,tributarytothesouthplatteriverabovechatfield Reservoir.Thisproject sprimarygoalistherestorationofpreble smousecriticalhabitatbut SugarCreekinthisareaisareproducingbrooktroutfisheryandthesedimentreductionefforts (costinganestimatedtotalof$3,879,000)willhavetheancillaryeffectofimprovingtheaquatic habitatinsugarcreek.thesugarcreeksedimentmitigationprojectisacooperativeproject among the US Forest Service, Project Participants and Douglas County, includes 29 new sedimenttraps,5culvertsremovinganexistingfishpassagelimitation,andotherfeatures,and isfullydescribedinappendixeofthecompensatorymitigationplan. Asathirdmitigationelement,theParticipantswillconstructthePlumCreekRestoration,which is described in further detail later in this document. The Plum Creek Restoration rebuilds portions of Plum Creek that have experienced significant erosion and, when the channel is rebuilt, it will have the benefit of providing more stable fishery habitat for two species of concern,thenorthernredbellydaceandthecommonshiner. 22

24 HabitatandRecreationintheSouthPlattebelowChatfieldReservoir Impact Water will be stored in Chatfield Reservoir from the Reallocation Project when the waterisbothphysicallyandlegallyavailable.increasedstorageofwaterinchatfieldreservoir will result in additional zero and low flow days which may result in additional loss of stream habitatbelowchatfieldreservoir. Mitigation 1. StreamHabitatImprovements:Tomitigatethepotentialimpactsofincreasedstoragein ChatfieldReservoir,theProjectParticipantswillfundstreamhabitatimprovementsonupto 0.5 miles of the main stem of the South Platte River downstream of Chatfield Reservoir. The specific site and project design will be done at the direction of the CPW at a cost of $100 per linear foot (or $264,000 for this project), which the Participants and CPW have determined is adequate to accomplish this work. The habitat improvement work will be targetedtobecompletedwithinfiveyearsofissuanceoftherecordofdecisionandbefore theinitiationofstorageofwaterinthereallocatedstoragespace. 2. ReservoirOperations:TheReservoirOperationsPlan( 4.1above)includesanagreement wherein the Project Participants who release their stored water through the Chatfield OutletManifoldandthensubsequentlyleavethewaterintheSouthPlatteRiverordivert their water at a downstream location will use their individual and collective good faith effortstostrategicallycoordinatetheirreleasestoassistindecreasingthenumberoflow flow or zero flow days in the South Platte River below Chatfield Reservoir. Such strategic releasesofwaterprovidetheopportunitytoincreasetheflowsbelowchatfieldreservoir whentheflowsarealreadylowfrompreexistingconditions. 3. Minimum Flow Requirements for Critical Low Flows. In order to avoid potential adverse effectsonwaterqualityduringcriticallowflowperiods,theusacehasrequiredtheproject ParticipantstopassflowsthroughChatfieldDamtotheSouthPlatteRiverduringstorage events that occur during critical low flows or would cause low flows. The Project Participantshavetheoptionto,attheirdiscretion,passflowsorreleasepreviouslystored water. If the Project Participants choose to release previously stored water, the requirement to pass flows will be deemed to have been met. If the Chatfield Water Providerschoosetoreleasepreviouslystoredwater,theymayworkwiththeStateEngineer toshepherdthereleasedstoragewaterthroughthereachsoughttobeprotectedbythis requirement to any diversion point downstream that any of the Providers are legally entitledtouse.thepassedflowwillequalthecriticallowflowforthemonth(table2),as measured at the Below Chatfield Gage (PLACHACO gage). The occurrence of critical low flowswillbedeterminedbymonitoringthebelowchatfieldgageandthecriticallowflows intable2.anyreleasesrequiredbytheusacewillbeincludedindeterminingoperationspursuant tosection4.1above. 23