DredgedMaterialManagementPreliminaryAssessment

ColumbiaRiverFederalNavigationChannel,

RiverMile3to105.5

Columbia&LowerWillametteRiversProject

U.S.ArmyCorpsofEngineersPortlandDistrict

December2017

Thispageisintentionallyblank

ExecutiveSummaryThepurposeofthisPreliminaryAssessment(PA)istodocumentthecontinuedviabilityoftheLowerColumbiaRiverfederalnavigationchannel(FNC)anddeterminetheavailabilityofdredgedmaterialplacementsitecapacitysufficienttoaccommodate20yearsofmaintenancedredging.ContinuedmaintenanceiswarrantedbasedonthesignificanteconomicbenefitsoftheColumbia‐SnakeRiverNavigationSystem,whichprovidedefficientmovementofover61milliontonsofcargovaluedat$30billionin2014andisthethirdlargestgrainexportsystemintheworld.However,thereisashortageofcapacityformaterialdredgedfromthechannelandtherealestateeasementsandrightsofentryforexistingplacementsiteswillexpirebeforetheendofthenext20yearchannelOperationsandMaintenance(O&M)period.TheforecastedaverageannualdredgingneedtomaintaintheLowerColumbiaRiverFNCis6.5mcy(130mcytotalforthenext20years).Thirteenofthenineteenexistinguplandplacementsitesarealreadyfullorhavecapacityforjustoneortwomoreplacementevents.Manyoftheselimitedcapacitysitescouldbefullwithinthenextfiveyears.Additionally,stablein‐waterplacementlocations,whichtheCorpsdependsonfor70%ofdredgedmaterialplacement,arebecomingincreasinglylimitedbecausethosesuitablelocationsarefillingupandbecomingtooshallowfordredgingequipmenttoaccess.Hydraulicanalysisshouldbeusedtoimprovein‐waterplacementtechniquesandexpandoptions.Further,thisassessmentidentifiedchallengesrelatedtodredgeequipmentavailabilityandthepotentialneedforadditionaloralternativeequipment.ThereisalsoaneedtoevaluateandplanformaintenanceofexistingrivertrainingstructuresthatsupportchannelO&Mbecausetheirconditionswillaffectfuturedredgingplansandvolumes.Forthesereasons,anewDredgedMaterialManagementPlan(DMMP)mustbedevelopedtoidentifynewchannelmaintenanceandplacementalternativesandprovidesufficientdredgedmaterialcapacitytoaccommodate20yearsofforecastedmaintenanceoftheLowerColumbiaRiverFNC.

i

TableofContents

1  StudyAuthorityandPurpose.....................................................................................................................1 

2  ScopeofAssessment......................................................................................................................................1 

3  ProjectDescription.........................................................................................................................................2 

  ProjectHistory.........................................................................................................................................2 

  CurrentProject........................................................................................................................................3 

4  Non‐FederalSponsors...................................................................................................................................6 

5  LowerColumbiaRiverContext..................................................................................................................6 

  Introduction..............................................................................................................................................6 

  Hydrology,HydraulicsandTides....................................................................................................6 

  Morphology...............................................................................................................................................7 

  SedimentBudget.....................................................................................................................................8 

  ShoalFormation......................................................................................................................................9 

  Conclusion..............................................................................................................................................12 

6  ChannelMaintenanceAssessment........................................................................................................13 

  Introduction...........................................................................................................................................13 

  Dredging..................................................................................................................................................13 

  RiverTrainingStructures................................................................................................................19 

  Assessmentofneedsforthenext20years..............................................................................22 

7  DredgedMaterialPlacementAssessment.........................................................................................24 

  Introduction...........................................................................................................................................24 

  UplandPlacement...............................................................................................................................27 

  ShorelinePlacement...........................................................................................................................30 

  OpenWaterPlacement.....................................................................................................................32 

  RegionalSedimentManagement(RSM)....................................................................................36 

  Assessmentofneedsforthenext20years..............................................................................37 

8  RealEstate.......................................................................................................................................................40 

  Non‐FederalSponsorResponsibilities.......................................................................................40 

  ExistingLands/Easements/Rights‐of‐Way..............................................................................40 

  Assessmentofneedsforthenext20years..............................................................................44 

ii

9  EnvironmentalandGovernmentConsultationsandCompliance...........................................44 

  ExistingEnvironmentalCompliance...........................................................................................44 

  ExecutiveOrder13175,ConsultationandCoordinationwithIndianTribalGovernments.......................................................................................................................................................47 

  ConsistencyofExistingDocumentswithOngoingO&MActivities................................48 

  Assessmentofneedsforthenext20years..............................................................................48 

10  EconomicAssessment............................................................................................................................49 

  EconomicBenefits...............................................................................................................................49 

  MaintenanceCosts..............................................................................................................................53 

  DeterminationthatContinuedMaintenanceisWarranted...............................................54 

11  Findings........................................................................................................................................................54 

12  Recommendation.....................................................................................................................................56 

13  References...................................................................................................................................................57 

1

1 StudyAuthorityandPurposeThisPreliminaryAssessment(PA)ispursuedundertheauthorityfortheColumbia&LowerWillametteRiversbelowVancouver,WAandPortland,OR(C&LW)Project.Overtime,thefederalnavigationchannel(FNC)hasbeenimprovedbyRiversandHarborsActs(RHA)of1878,1892,1902,1912,1930,and1962,andmostrecentlytheWaterResourcesDevelopmentAct(WRDA)of1999andConsolidatedAppropriationsActof2004.ThisPAhasbeenpreparedinaccordancewithU.S.ArmyCorpsofEngineers(Corps)EngineeringRegulationER1105‐2‐100AppendixE‐15ofthePlanningGuidanceNotebookdated22April2000.

Allfederallymaintainednavigationprojectsmustdemonstratethatthereissufficientdredgedmaterialplacementsitecapacityforaminimumof20years.BecausetheColumbiaRiverchannelservesmultipledeep‐waterportsasanintegratedsystemalonga103‐milelongprojectlength,reliableserviceoftheFNCispredicatedontheavailabilityoftheentirechanneltoprovideuninterruptedtransittofullyloadedvesselsdraftingtoauthorizedchanneldimensions.TheLowerColumbiaRiverportsandshipoperatorsdependonfullavailabilityofthepresentlyauthorizedFNCtorealizetheproject’sNationalEconomicDevelopmentbenefits.ThepurposeofthisPAistodocumentthecontinuedviabilityoftheprojectanddeterminetheavailabilityofdredgedmaterialplacementsitecapacitysufficienttoaccommodate20yearsofmaintenancedredging.Thisassessmentsuggeststhereisnotenoughcapacitytoaccommodatemaintenancedredgingforthenext20years,andtheassessmentthereforerecommendsadetailedDredgedMaterialManagementPlan(DMMP)studyandprovidesinformationnecessarytorecommenditsprioritizationintheCorpsPortlandDistricts’budgetaryprocess.

2 ScopeofAssessmentThisPAisformaintenanceofthemainColumbiaRiverFNCportionofC&LWProjectfromVancouver,Washington(RiverMile[RM]105.5)downstreamtotheMouthoftheColumbiaRiver(MCR)entrancechannelthePacificOcean(RM3).TheLowerWillametteRiver(PortlandHarbor)portionofC&LWProjecthasshallowerdepthsandareasoflimitedaccessibility,ahigherproportionoffinegrainedmaterial,shoalingrelatedtoextensiveportandbankinfrastructure,andenvironmentalrestrictionsthatrequireamaterialmanagementstrategywhichisdifferentfromthestrategyfortheColumbiaRiverchannel.Therefore,thisassessmentfocusesonthemainColumbiaRiverFNCanddoesnotrepresenttheLowerWillametteRiver,auxiliarychannelsorotherfeatureswhicharealsoauthorizedaspartoftheC&LWProject.Otherfederalandnon‐federaldredgingwithintherelatedgeographicareamayalsoaffectplacementcapacityfortheColumbiaRiverFNC,buttoalimitedextentbecausethevolumesareproportionallyless.

Project‐levelsummariesaresufficientforthisPA.TheDMMPwillstudyindividualreaches.

2

ThePAfirstsummarizesthehistoryandcurrentfeaturesoftheLowerColumbiaRiverFNCandchannelO&Mchallengesrelatedtothephysicalenvironment.Next,thePAreviewscurrentchannelO&Manddredgedmaterialplacementpractices,forecastsneedsforthenext20years,andrecommendstopicsforfurtherstudy.ThePAalsoassessesthestatusofexistingrealestateandenvironmentalcompliance,andfutureneedsandrecommendationsforimprovement.Lastly,thePAincludesaneconomicassessmentoftheproject.

3 ProjectDescription

ProjectHistoryTheRHAof1878authorizeda20ftdeepnavigationchannelintheColumbiaRiver.Theauthorizeddepthwasincreasedto25ftbytheRHAof1892andtheauthorizedwidthwassetat300ftbytheRiversandHarborsActof1902.

Theauthorizeddepthwasthenincreasedto30ftbytheRiversandHarborsActof1912.Priortoconstructionofthe30ftchannel,dredgingwaslimitedtoafewveryshallowreachesoftheriverwherethenaturalcontrollingdepthswereinthe12‐to15‐footrange.Whenthechanneldepthwasincreasedto30ft,therewassignificantincreasedshoalingassociatedwiththenewdepth.Maintenancedredgingwasincreasedandmanyhydrauliccontrolstructures(piledikes)werebuilttomaintaintheauthorizedchannel.

Theauthorizeddepthandwidthwereincreasedto35ftand500ft,respectively,bytheRiversandHarborsActof1930.Constructionoccurredfrom1930to1935.From1936to1957,channelalignmentadjustmentsweremadethataddedtothedredgingrequirements.Duringthisperiod,dredgingaveraged6.7millioncubicyards(mcy)peryear.By1958,thechannelalignmenthadstabilizedbutdredgingwasaugmentedtoincreasethedepthofadvancemaintenancedredgingfrom2to5ftbelowauthorizeddepthtoallowthechanneltoshoalforayearbetweendredgingeventsandstillprovideauthorizeddimensions.

Theauthorizeddepthwasincreasedto40ftandtheauthorizedwidthwasincreasedto600ftbytheRiversandHarborsActof1962.Constructiontookplaceinstagesbetween1964and1976.Thenavigationchannelgenerallyfollowedtheriver'sthalweg(thedeepestpartoftheriverchannel),andmostofthechannelwasnaturallydeeperthantherequired40ft.Shoalstendedtoforminchannelreacheswherethenaturaldepthwaslessthan40ft.From1976to1996,dredgingaveragedapproximately5.5mcyperyear(excludesemergencydredgingrelatedtothe1980eruptionofMountSt.Helens).

ThepreviousLowerColumbiaRiverDMMPwaspreparedin1998andbecamethebasisforthe2003ColumbiaRiverChannelImprovementProjectSupplementalIntegratedFeasibilityReportandEnvironmentalImpactStatement(SEIS)finalplanforconstructionandthefirst20yearsofmaintenanceofthe43‐footColumbiaRiverchannel.Thecurrent43‐footchannelwasauthorizedbytheWRDAof1999andConsolidatedAppropriationsAct

3

of2004.Constructionofthe43‐footchanneloccurredfrom2005to2010.TheplacementsitecapacitiesusedasthebasisfortheCRCIP2003SEISwerefromthe1998DMMP.Theseprojectedcapacitieswerenotreducedbythevolumeofdredgedmaterialplacedatthesitesfromongoingmaintenanceoftheexisting40‐footchannelduringtheperiodoftimebetweenthe1998DMMPandtheconstructionofthe43‐footchannel.Asaresult,whendredgedmaterialcontinuedtobeplacedinuplandsitesfrom1999‐2004,thissignificantlyreduceduplandsitecapacityavailableforconstructionandmaintenanceofthe43‐footchannelstartingin2005.Also,severaluplandsitesidentifiedintheCRCIP2003SEISwereeliminatedforvariousreasons,andremainingsiteswerenotusedasplannedduring43‐footchannelconstruction.Together,thesechangesresultinthelossofanestimated24mcyofuplandplacementcapacityforthelongtermmaintenanceofthe43‐footchannel.

TheCorpsdevelopedtheColumbiaRiverFederalNavigationChannelInterimOperations&Maintenance(O&M)Plan(interimO&MPlan)in2013forchannelmaintenancethrough2018.However,placementofdredgedmaterialundertheinterimO&MPlanislimitedtotheactualremainingcapacityandreducednumberofsuitablesitescomparedtowhatwasinitiallyselectedintheCRCIP2003SEIS.RefertotheinterimO&MPlanforadditionaldiscussion.

CurrentProject Constructionofthe43ftchannelwascompletedin2010andtheProjectisnowinO&Mphase.Thechannelismaintainedusingacombinationofdredgingandhydrauliccontrolstructures(suchaspiledikes).TheinterimO&MPlanprovidesguidanceforannualdredginganddredgedmaterialplacement.Advancedmaintenancedredging,thepracticeofexcavatingshoalstoadepthand/orwidthgreaterthantheauthorizednavigationchanneldimensionsforthepurposeofmaintainingtheauthorizeddimensionsforalongerperiodoftimebetweenmaintenancedredgingevents,iscurrentlyallowedupto5ftbelowauthorizeddepth(generally48ft)andupto100ftoutsidetheauthorizedchannelwidth.

TheLowerColumbiaRiverdeepdraftFNCevaluatedinthisPAisdefinedas:

Mainnavigationchannel,43ftdeepandgenerally600ftwide,fromtheMouthofColumbiaRiver,RM3toVancouver,WA,RM105.5.

Turningbasin43ftdeepatAstoria,OR,RM13. Turningbasin40ftdeepatLongview,WA,RM66.5. Turningbasin43ftdeepatKalama,WA,RM73.5. LowerTurningbasin43ftdeepatVancouver,WA,RM105.5. Navigationchannel43ftdeepand400ftwidefromtheColumbiaRiverRM102

extending1.5milesintolowerOregonSlough.

4

ColumbiaRivernavigationchannelreachesaredefinedasfollows:    Table3‐1:NavigationChannelReacheswithinLowerColumbiaRiver

Reach #/ID 

Reach Name  Downstream RM* Limit 

UpstreamRM Limit 

Turning Basins

01/LDS  Lower Desdemona  03+00 06+22 ‐ 

02/UDS  Upper Desdemona  06+22 10+00 ‐ 

03/FLV  Flavel Bar  10+00 13+30 RM 13, 43 ft

04/USN  Upper Sands  13+30 17+28 ‐ 

05/TNG  Tongue Point Crossing 17+28 21+20 ‐ 

06/MLN  Miller Sands  21+20 25+15 ‐ 

07/PIL  Pillar Rock Ranges  25+15 28+40 ‐ 

08/BKW  Brookfield‐Welch  28+40 32+30 ‐ 

09/SKM  Skamokawa Bar  32+30 36+31 ‐ 

10/PGT  Puget Island  36+31 40+40 ‐ 

11/WAN  Wauna Driscoll  40+40 44+30 ‐ 

12/WST  Westport Bar  44+30 48+15 ‐ 

13/EUR  Eureka Bar  48+15 51+45 ‐ 

14/GUL  Gull Island Bar  51+45 55+30 ‐ 

15/STL  Stella‐Fisher Bar  55+30 59+20 ‐ 

16/WLK  Walker Island Bar  59+20 63+10 ‐ 

17/SLG  Slaughters Bar  63+10 67+06 RM 66.5, 40 ft

18/LDB  Lower Dobelbower Bar 67+06 69+50 ‐ 

19/UDB  Upper Dobelbower Bar 69+50 72+40 ‐ 

20/KLM  Kalama Bar  72+40 76+25 RM 73.5, 43 ft

21/LMT  Lower Martin Island Bar 76+25 80+20 ‐ 

22/UMT  Upper Martin Island Bar 80+20 83+42 ‐ 

23/STH  St. Helens Bar  83+42 87+15 ‐ 

24/WAR  Warrior Rock Bar  87+15 90+20 ‐ 

25/HEN  Henrici Bar  90+20 94+05 ‐ 

26/WLW  Willow Bar  94+05 97+40 ‐ 

27/MGN  Morgan Bar  97+40 101+20 ‐ 

28/VBR  Lower Vancouver Bar** 101+20 104+30 ‐ 

29/VTB  Vancouver Turning Basin*** 104+30 105+28 RM 105, 43 ft

*RiverMiles(RM)arelabeledasRiverMileNumber+Hundredsoffeetupstream(e.g.RM3+25=2500feetupstreamofRiverMile3).Certainrivermilenumbersareintentionallysetatrecognizablefeaturesandasaresult,individualrivermilescanbedifferentlengths.Onaverage,rivermilesintheColumbiaRivermorecloselyapproximatethedistanceofastatutemilethananauticalmile.

**OregonSloughislocatedatRM102+00.

***VancouverTurningBasin(Upper)RM105+28to106+24ismaintainedtolessthanauthorizeddepth35ftbasedoncurrentuserneedsandisnotincludedinthisPA.

SeeoverviewmapinFigure3‐1.

5

Figure3‐1:LowerColumbiaRiverFNCReaches

6

4 Non‐FederalSponsorsThenon‐FederalsponsorsforthisprojectarethePortofPortland,OR;thePortofVancouver,WA;thePortofKalama,WA;thePortofLongview,WAandthePortofWoodland,WA.Thenon‐FederalsponsorsandU.S.ArmyCorpsofEngineers(Corps)enteredintotheProjectCooperationAgreement(PCA)forConstructionofImprovementsforEcosystemRestorationandNavigationontheColumbiaRiverportionoftheColumbia&LowerWillametteRiversFederalNavigationChannel,OregonandWashingtononJune23,2004.ThisPCAcontinuestoapplytoongoingchannelmaintenanceforaslongastheprojectremainsauthorized.

5 LowerColumbiaRiverContext

IntroductionTheColumbiaRiverisadynamicsystemthatposesanannualchallengeformaintenanceoftheFNCtotheauthorizeddepthof43ft.Thissectionprovidesimportantcontextfortheassessmentofpotentialimpedimentstocontinuedmaintenance.RefertotheColumbiaRiverFederalNavigationChannelInterimOperations&Maintenance(O&M)Planforadditionaldetail.Forpurposesofthisreport,theLowerColumbiaRiverisdefinedastheColumbiaRiverdownstreamofVancouver,Washington(RM105.5)totheMouthoftheColumbiaRiver(MCR)entrancechannelatthePacificOcean(RM3).

Hydrology,HydraulicsandTidesTheColumbiaRiverflows1,210milesfromCanadathroughtheStatesofWashingtonandOregontothePacificOcean,anddrainsanareaof259,000squaremiles(Hickson,1961).MajortributariesaretheSnakeandWillametteRivers.Theriverisregulatedbyaseriesofdams.BonnevilleDamisthefurthestdownstreamatRM145.ColumbiaRiverdischargesaredependentonweather,reservoiroperations,andoceantides.ThehighestflowsgenerallyoccurinMayorJuneasaresultofsustainedsnowmeltintheupperwatershedandthe2‐yrfloodpeakatTheDalles,Oregon(RM192)is360,000cubicftpersecond(cfs)withregulation.Lowflows,typicallyinthe100,000cfsrange,occurinSeptemberandOctober,afterthesnowmeltbutbeforethewinterrains(Eriksen,1989).

Thelowerriversub‐basins,thosewestoftheCascadeCrest,containonlyabout8‐percentofthetotalbasinarea,butcontribute24‐percentofthetotalriverflowbelowBonnevilleDam;thus,briefwinterfreshetscausedbyrunofffromrainfall,orrain‐on‐snowinthelowersub‐basinsmayoccurfromDecemberthroughMarch.Forexample,onFebruary11,1996themaximumdailyColumbiaRiverflowatTheDalleswas376,000cfs,andflowintotheColumbiaRiverfromtheWillametteRivertributaryatRM101wasnearly400,000cfs.

7

Thecombinedeffecttotaled865,000cfsatRM55oftheLowerColumbiaRiver(downstreamofLongview,WA)(Simenstadetal,1984).Overall,peakwaterlevelsintheLowerColumbiaRivergenerallyoccurinJanuaryandJune,andminimumlevelsoccurAugustthroughOctober(seeFigure5‐1).

Figure5‐1:RiverLevelatVancouver,WA

TidalinfluenceonriverineflowisgreatestinthereachesdownstreamofRM33andchieflyduringlowflowperiods.PartialflowreversalcanoccurasfarupstreamasRM90duringlowflowperiods(Eriksen,1989).Theverticalplaneofreferenceismeanlowerlowwater(MLLW)intheriverdownstreamofHarringtonPoint(RM22)andadoptedlowwater(ColumbiaRiverDatum[CRD])upstreamtoVancouver.Theauthorizednavigationchanneldepthis43feetbelowzerodatum.Zero(0)CRDroughlycorrespondstotheriverlevelatminimumoperatingdischargefromBonnevilleDam(70,000cfs).Averagetidalrangeisabout8ftatthemouthoftheColumbiaRiver(extremeis13ft)andabout3ftatlowriverstagesatVancouver.AnnualfreshetshavelittleeffectonriverlevelatthemouthoftheColumbiaRiver,butaverageabout12ftatVancouver(Headquarters,U.S.ArmyCorpsofEngineers,2014).

MorphologyTheestuaryis4‐5mileswideandextendsupstreamfromtherivermouthtoaboutRM25.UpstreamofRM25,themainriverchannelis1,700‐3,000ftwide,withminorbifurcations

8

aroundislands(bifurcationisaforkintheriverwhereitbranchesintomorethanonestreamofflow).Bendstendtobegradual,exceptwherebasaltcliffscontrolthealignment.

Thebedofthemainchanneliscomposedoffineandmediumsands(0.125‐0.500mm).Thenaturalriverbanksconsistof10to20ftofclay‐silt,overlyingmuchdeepersanddeposits.Sandybeachesoccuronlywheredredgedmaterialhasbeenplacedalongtheshore(Eriksen,1989).

SedimentBudget

5.4.1 SuspendedSedimentLargely,thedrainagebasin(ColumbiaPlateau)oftheColumbiaRiverconsistsofexposedbedrock,andregionsofrockoverlainwiththin,surficialsoildeposits.TheclimateoftheColumbiaPlateaurangesfromsemi‐aridtoarid.Asaresult,thesedimentyieldfromthebasinislow–thelowestofanymajordrainageinNorthAmerica.MostmeasurementsandestimatesofannualsuspendedsedimentloadpassingBonnevilleDamwereperformedbeforethespringfreshetwaseliminatedbyflowregulation,howevertheacceptedfigureforannualloadforthemodernperiod(post1969)is4.5to5.1mcy(VolumemeasurementswereconvertedfromMetricTons(Tonnes)toCubicYardsusingthefollowingformula,which

assumeswetsanddensity(notcompacted)at1,922kg/m3: , .

,

1.47 ).AftertheeruptionofStHelensin1980,theannualsuspendedsedimentload

measuredattheriverine‐estuaryboundarytemporarilyincreasedto27mcy(Sherwoodetal,1984).

Duringhighregulateddischarges,75to80percentofthesuspendedloadbyweightiscoarsesilt‐sizeandfiner(modalaverage=0.030mm(mediumsilt)).Priortoflowregulation,siltscomprised45‐50percentofthesuspendedload,andfine‐andvery‐finesandmadeupmostoftheremainingfractionofthesuspendedsedimentload.Mostofthisfinesedimentdoesnotdepositinthenavigationchannel,butinsteadsettlesoutinlowervelocityareasoftheriverorremainssuspendeduntilitreachesthePacificOcean(Beasleyeta,1986),(Karlin,1980),(Simenstadetal,1984).Since1980,sedimentfromMountSt.HelenshasincreasedthetotalannualsedimentloadsdownstreamoftheCowlitzRiver(RM68)butmostofthesedimenthasbeensmallerthanthatfoundinthebedoftheColumbiaRivernavigationchannel(Eriksen,1989).

5.4.2 BedMaterialandBedloadThebedmaterialoftheColumbiaRiverfromBonnevilleDam(RM145)downstreamtoRM15consistsofmediumsand,withsomefinersandfractions.FromRM15downstreamtoRM11,coarsesandrepresentsanincreasingfractionofthebedmaterialasmarinetransport(floodcirculation)increases.FromRM11downstreamtotheocean,asflood‐

9

inducedtransportdominates,thefractionofcoarsesandmayexceedthemediumsandfractiononthechannelbottom(Sherwoodetal,1984).

Verylittledataareavailableforthebedloadbudgetinboththeriverandestuary.However,researchershaveestimatedthefluvialsupplyofbedloadsedimentdownstreamofBonnevilleat500kcy/year(Haushildetal,1966)(VolumemeasurementswereconvertedfromMetricTons(Tonnes)toCubicYardsusingtheformulainSection5.4.1).

ShoalFormation

5.5.1 SandWaveShoalsSandwaves,giantripplesordunesofsandformedfrommaterialontheriverbed,havelongbeenrecognizedasashoalingproblemintheColumbiaRiver.Large,migratingsandwavesarethepredominantbedformoftheColumbiaRiverfromBonnevilleDam(RM145)downstreamtothemouth.BetweenBonnevilleDamandtheWillametteRiver(RM101);sandwavescover45%oftheColumbiaRiverchannelbottom;fromtheWillamettetotheCowlitzRiver(RM68),sandwavecoverageis80%;andfromtheCowlitztothemouth,coverageincreasesto86%(Whettenetal,1969).Mostofthetime,onlythepeaks(crests)ofsandwavesgrowshallowerthanauthorizedchanneldepthandrequiredredging.Dredgingtypicallyinvolvestheselectiveremovalofthecrestofeachindividualsandwave,whichisnotefficientforconventionaldredgingtechnologybecausethecrestsareseparatedbydeeperareasthatdonotrequiredredging(Levinetal,1992).Whilethevolumeofmaterialdredgedfromanindividualsandwaveshoalissmall,typicallylessthan10kcy;collectivelytheyarenumerousenoughtorepresentasignificantamountofthetotaldredgingvolume.

FromBonnevilleDamtoRM15intheestuary,bedforms(sandwaves)inthenavigationchannelareunidirectionalandmigratedownstream;fromRM14to11,bedformsaretidallyreversing;andfromRM11tothemouth,wheretransportisflood‐currentdominated,sandwavesmigrateupstream.Sandwavesmayformanywhereintheriverandestuarywhereflowvelocitiesapproachorexceed2feet/s.Therateofmigrationandsizeofsandwavesincreasewithhigherflowvelocities.Duringlowdischarges,migrationratesmaybe1‐2feet/day;athigherregulateddischarges,migrationratescanbe10to20timeshigher.Duringhighwinterfreshets(e.g.February1996),migrationratesofsandswaveswereestimatedtobeashighas200feet/daydownstreamoftheWillametteRiver(RM101).Migrationratesareanindicatoroftransportmode–atlowrates,sedimentmovesasbedload;athigherrates,bedmaterialistransportedinsuspension(i.e.bedmaterialload)(Hubelletal,1971),(Royetal,1979).SeesandwavesinFigures5‐2and5‐3.

10

Figure5‐2:Sandwavemovementandgrowthover3‐weekperiodatWillowBar(RM97).PointAshowsasandwavecrestmoving100ftdownstreamandPointBshowsasandwavecrestgrowing2ftshallower,creatingashoalaboveauthorizeddepth.ColumbiaRiverdischargefromBonnevilleDamduringthistimerangedfrom300to400kcfs.

Figure5‐3:Sandwavepeakformintermittentshoalingaboveauthorizeddepthof43ftshowninred.LocationisUpperMartinBar;surveydated4‐Oct‐2011.

11

5.5.2 CutlineShoalsCutlineshoalsformfromthecutlinetowardthechannelcenterandcanextendseveralthousandfeetalongthechannellengthparalleltoflow.Theseshoalsaremuchlargerinvolumethansandwaves(dredgingvolumestypicallyover100kcy)andoccurannuallyatthesamelocations,mainlydownstreamofLongview,WA(RM68).Theyareespeciallysevereinareasoftheriverthatwerelessthanauthorizeddepthpriortoconstructionoftheexistingchannel.Theseshoalsoccurontheinsideoflongbendsandonstraightriverreaches.SeecutlineshoalsinFigures5‐4and5‐5.Theprimarycauseisgravitypullingbedloaddownthesideslopesandintothenavigationchannel.Asrivercurrentsmovebedloaddownstreamoverareaswheretheriverbottomslopesdowntowardthechannel,gravitydeflectsthesedimentdowntowardthechannel.

Figure5‐4:Cutlineshoalformationfrombedloadmaterialmovingacrossandalongtheriverbottom.

12

Figure5‐5:Cutline,continuousshoalingformsaboveauthorizeddepthof43ftshowninred.LocationisSkamokawaBar;surveydated20‐Jul‐2011.

ConclusionTheColumbiaRiverisadynamicsystemthatposesanannualchallengeformaintenanceoftheFNCtotheauthorizeddepthof43ft.

Asdiscussedinthissection,theconvergenceofuniquehydrologyandmorphologycausessedimentbedloadtoformshoalinginthenavigationchannelduringpeakriverlevels,(latespring)whichareimmediatelyfollowedbythelowestriverlevels(latesummerandfall).Sincetheauthorizednavigationchanneldepthisrelativetozerodatum,iftheriseinriverlevel(verticalfeetabovezerodatum)isgreaterthanthedeposition(verticalfeet)ofshoalinginthechannel,shipswillhaveadequatewaterdepthtobeabletopassovertheshoal.However,ifthereisstillshoalinginthechannelabovetheauthorizeddepthwhenriverlevelsapproachzerodatum,shipswillberestricted.

TheColumbiaRiver’snaturalsequenceofpeakriverflowsandshoalingfollowedbylowestriverlevelsresultsinashort,criticalwindowofopportunity,lastingapproximatelytwomonthsfrommid‐Junetomid‐August,toremoveshoals.Duringthiscriticaltime,limiteddredgingequipmentthatissharedregionallymustbemobilizedtoremoveshoalingaboveauthorizedchanneldepthbeforethecombinationofshoalingandlowwaterlevelimpactsnavigationsafetyandefficiency.Advancedmaintenancedredgingatothertimesoftheyearisusedtoreducethevolumeofshoalingaboveauthorizeddepthtoamanageablelevel.

13

6 ChannelMaintenanceAssessment

IntroductionAnnualmaintenanceisperformedusingacombinationofdredgingandhydrauliccontrolstructures(suchaspiledikes).ThepurposeofthissectionistosummarizerecenthistoryandevaluatethecurrentconditionsofchannelmaintenanceintheColumbiaRiverFNCinordertobetterunderstandfuturemaintenanceneedsandhighlightpotentialimpedimentstocontinuedFNCoperationsandmaintenance.Thisassessmentconsidersthreetimeperiodsinordertoforecastneeds:1986‐2004(40ftFNCmaintenance),2005‐2010(43ftFNCconstruction),and2011‐2016(43ftFNCmaintenance).

Dredging

6.2.1 DredgingEquipmentThechannelisannuallymaintainedbythreehopperdredgesandonepipelinedredge.TwoofthehopperdredgesareownedbytheGovernment,theESSAYONSwhichisconsideredamediumsizeddredge,andtheYAQUINAwhichisasmallerdredge.Oneadditionalhopperdredgeisemployedthroughcontract.The30‐inchpipelinedredge,theOREGON,worksundercontractwiththePortofPortland.Clamshelldredges,whichremoveshoalsmechanicallyusingbucketsoperatedbyfloatingcranesonbarges,arebestsuitedformaterialthatcannotberemovedbyhydraulicdredgingorworkincloseproximitytostructureslikedocks,andsoarenotroutinelyneededforchannelO&M.PhotosofdredgingequipmentareshowninFigure6‐1.

Hopperdredgesaremobilevessels(ships)thatcanquicklymovebetweenshoalsandaredesignedtooperateinunprotectedseaconditions.Forthesereasons,hopperdredgesaremostefficientforremovalofsmallvolumesandwaveshoalsintheriverandlargercutlineshoalsintheestuary.Dredgedmaterialispumpedfromtheriverbottomintoatemporarystoragebasin(hopper)locatedinsidethedredge.Oncethehopperisfull,thedredgestopsdredging,transitstotheplacementlocation,andtypicallyplacesthematerialin‐waterbyopeningthebottomofthevesseltoreleasethematerialusingforceofgravity.Thein‐riverplacementlocationmustbedeepenoughforthedredgetosafelyaccessbasedonthevessel’sdraftbelowthewatersurface.TheESSAYONStypicallyneedsdepthsgreaterthan35feetandtheYAQUINAneedsdepthsgreaterthan20feet.Whenpossible,dredgesareassignedtoshoalsthatarelocatedclosesttoin‐riverplacementlocationsthatarebestsuitedtotheirlimitingdraft,tomaximizeproduction.Somecontracthoppersareequippedtohookuptoapipelineandpumpdredgedmaterialbackoutofthehoppertoplacementsitesonshore,buttheESSAYONSandYAQUINAdonothavethatcapability.Becauseittakesapproximatelytwiceaslongtoclearashoalwhenmaterialispumpedbackoutofahopperdredge(comparedwithin‐waterplacement),atasignificantlyhighercost,this

14

methodhasnotbeenusedforrecentchannelmaintenance.Becausehopperdredgesareself‐propelled,theyarenotphysicallylimitedtoplacementsitesnearadredgingarea;however,increasedhauldistancetranslatestoincreasedtimeandcostrequiredtoremoveashoal.

ThepipelinedredgeOREGONismostefficientforremovaloflargercutlineshoalswherethereisalargequantityofmaterialconcentratedwithinasmallarea,becausethedredgeisnotself‐propelledandistypicallyattachedtoonetotwomilesoffloatingpipelineduringoperation,soasignificanteffortisinvolvedtomovethedredgebetweenshoals.Materialispumpedfromtheshoaltotheplacementsitethroughthepipelineinonecontinuousaction,sothedistancebetweentheshoalandtheplacementlocationislimitedbythephysicallengthofpipelineavailable.Thispipelinedredgeshouldbeusedinmoreprotectedreachesoftheriverbecausethefloatingpipelineisnotdesignedtowithstandlargewavesorhighflowvelocitiesandcouldbreakapartunderthoseconditionsinthelowerestuary.Thepipelinedredgeisequippedtoplacematerialin‐wateroruplandatthesameproductionrate,bypumpingmaterialthroughthepipelineeitherbackintotheriverorontoshore.Forthisreason,thedredgeOREGONismoreefficientthanhopperdredgesforuplandandshorelineplacementofdredgedmaterialintheLowerColumbiaRiver.

TheCorpsPortlandDistrictleadsaregionaldredgingprogramontheWestCoastwithotherCorpsDistricts,anddredgingequipmentissharedbetweentheCorpsDistrictsthroughthisprogram.ThisregionalcollaborationisnecessarytocreateaneffectiveandfeasibledredgingplanthatoptimizesprojectfundingandresourcesavailablefromthelimitednationalhopperdredgingfleetofGovernmentandcontracthopperdredges.TheESSAYONSandYAQUINAarebasedontheWestCoastinPortlandDistrict.However,theworkavailableforcontracthopperdredgesislocatedontheEastandGulfcoastsoftheUnitedStates,withtheexceptionoftheannualWestCoastcontract,soeachyearonecontracthopperdredgemusttransitthroughthePanamaCanaltoandfromtheWestCoast(atanincreasingcost)inordertomeettheregionaldredgingprogramneeds.Thescheduleforthisregionaldredgingisestablishedthroughannualregionalplanningmeetings,andismeanttomeettheneedsofalltheCorpsDistrictsinvolved;however,therecouldbetimesthatdredgingisneededintheLowerColumbiaRiverFNC,butequipmentisnotreadilyavailablebecauseitisbeingusedtomeettheneedsofanotherCorpsDistrict.ThisDMMPwillconsiderequipmentavailabilityandproviderecommendationsbasedonlessonslearnedfromprioryearsofregionaldredgeplanning.

15

Figure6‐1:DredgingEquipmentonLowerColumbiaRiver.

6.2.2 Historicaldredgingevaluation 

Figure6‐2showsannualO&MdredgingandConstruction(newwork)dredgingvolumesfortheperiod1986to2016.

Theannual40ftchannelO&Maveragefrom1986to2004was6.8mcy.Withunusuallyhighfloodyears1996‐1997removed,theaveragedropsto6.1mcy.Becausedredgingisoftenlimitedbyannualfundingconstraints,dredgingequipmentavailabilityorworkwindows,andnotalwaysrelatedtoshoalingconditionsordredgingneeds,thesedredgingvolumesmaynotaccuratelyrepresentthepastneedfordredging,onlytheamountsthatwereabletobedredged.

Duringconstructionofthe43ftdeepdraftchannelovera6‐yearperiodfrom2005to2010,theoretically,annualO&Mdredgingvolumesshouldhaveremainedconsistentwiththeannual40ftchannelaverageof6.8mcyandtotalColumbiaRiverdredgingshouldhaveincreasedbythevolumeofconstructionmaterial.Inactuality,annualO&Mdredgingvolumesdecreasedduringthistimetoanaverageof4.5mcy.Thereasonforthisisthatconstructionofthe43ftchanneltooksixyearsandduringthistimethechannelwasmaintainedasa40ftchannel,eveninareasthathadalreadybeendeepenedto43ft.Inotherwords,thefirstareasdeepenedto43ftwereallowedtoshoalbackto40ftwhilethe

16

remainderofthe43ftchannelwasconstructed.TheresultoflessO&MdredgingduringconstructionwasabacklogofO&Mdredgingneedattheendofconstructionin2010.

Eachyearshoalsthatareformedduringannualhighflowsmustbedredgedbeforethelowwaterseason,howeverwithlimitedequipmentresourcesavailable,ittakesmonthsforthedredgestoremovethelargeannualquantitiesofmaterial.Advancedmaintenancedredging(AMD)inthefallandspringisusedwhenpossibletoreducethevolumeofshoalingthatformsaboveauthorizeddepthtoamanageableleveltominimizeimpactstonavigation.Ideally,thechannelisdredgedannuallytoadvancedmaintenancedepthof48ftandwidthsof100ftoutsidetheFNCwhereneeded,andeachdredgeispairedwithshoalingandplacementoptionsthatmaximizeefficiency.

TheactualandplannedO&Mdredgingvolumesforthefirstyearafterconstruction(2011)appeartobeconsistent.However,theplannedO&Mvolumereflectsfulladvancedmaintenancedepth(48ft)alongtheentirechannellength,andtheactualquantitydredgedwasnotabletoachieveauthorizeddepth(43ft).CausesfortheincreasedshoalingvolumesincludethebacklogofO&Mdredgingneededafterchannelconstructionandhigh,sustainedriverflows,whichdestabilizedthenewchannelandcreatedsandsourcesalongthebanksoftheriver.TheactualO&Mdredgingthatwouldhavebeenneededin2011,thefirstyearafterconstruction,toachieveadvancedmaintenancedepthandwidthatcriticalshoalsinthe43ftchannelwouldhavebeenupwardsof12mcy,basedonchannelsurveyvolumes.Becauseoflimiteddredgeavailabilityandfunding,actualdredgingwaslessthan8mcyandasaresultadvancedmaintenancedepthwasnotachieved.

Withoutadvancedmaintenance,shoalsrapidlyre‐forminareasthathavebeendredged,whiledredgesarestillworkinginotherareastocleartheentirelengthofthe100‐milechannel.Inotherwords,shoalsre‐formfasterthandredgescanremovethemandthereisalwaysatleastoneshoalaboveauthorizeddepthinthechannel.Asaresult,situationsarisewhentheonlyavailableequipment(oftennotbestsuitedforthejob)issenttoaddressthehighestpriorityshoalinreal‐time.Thisreducestheefficiencyofdredgingoperationsandincreasesunitcosts.Consequently,thisimpactsrivertrafficbecauseifriverlevelsarenothighenough,commercialshipscannotpassovershoalsthatareshallowerthanauthorizeddepthandmustloadlesscargosotheydonotdraftasfarbelowthewatersurface.Theseshipdraftrestrictionsresultinadverseeconomicimpacts.Thiswasthecasein2011and2012,thefirst2yearsof43ftchannelO&Mandunusuallyhighriverflowandshoalingyears,whenasmuchas80%ofthevolumedredgedwasfromshoalingshallowerthanauthorizeddepth,notadvancedmaintenance,andtherewerecommercialshipdraftrestrictions70%ofthattime.

However,aftersufficientfundingwasprovidedfordredgingtoachieveadequateadvancedmaintenanceinfall2014,thesituationgreatlyimproved.Therewasbelowaveragepeakflowin2015andaveragepeakflowin2016,whichresultedinreducedshoalingvolumes

17

thatwerecloserto40ftchannelaverages.Additionally,becausetheinitialchannelconditionattheendof2014wasaconditionofgreateradvancedmaintenancedepth,whenshoalingdevelopedin2015and2016,mostofthevolumedevelopedbelowtheauthorizeddepthof43ftinsteadofformingrestrictingshoalsabove43ft.Dredgingin2016wasthereforeabletofocusonremovingmaterialasitaccumulatedinthedepthrangeof48ftto43ft,beforeitbecameshallowerthan43ft.AsaresultofbeingabletoachievethissustainedAMDinamajorityofthesystem’sreaches,channelconditionreportsshowedadecreaseinshoalingabovetheauthorizedchanneldepthincomparisontoprioryears.Consequently,therewerenoshipdraftrestrictionsin2016,thefirstfullyearwithoutrestrictionssincemaintenanceofthe43ftchannelbeganin2011.

Additionally,thedredgeassignmentshavebeenoptimizedusinglessonslearnedfromprioryearssothatby2016,eachdredgewasdirectedtoshoalsandplacementsitesthatbestfitthecapabilityofthatspecificdredge.Thecontracthopperdredgeconcentratedonlarger,lessdynamicshoalsbecausecontractdredgesaretypicallylessfamiliarwiththechallengesofremovingsandwaveshoalingandthereisagreatereffortforcontractadministration,acceptanceandpaymentforeachworkareaascomparedtotheGovernmentdredges.ThedredgeESSAYONSremovedtheremainingshiftingshoalsdownstreamofLongview,WAwherethereismorein‐riverplacementcapacityatgreaterdepthsandthemostmaneuverabledredgeYAQUINApickedupsandwavespotshoalsupstreamtoVancouver,WAwheretheriverbottomisshalloweroutsidethechannelandthereislimitedin‐riverplacementcapacityforlargerhopperdredges.DredgeOREGONassignmentswerealsooptimizedbyfocusingonlarge,cutlineshoalsincloseproximitytouplandorshorelineplacementsites,whichismostefficientforthepipelinedredge.Theannualregionalhopperdredgescheduleshavealsobeencraftedtoallowmoreflexibilitytoadjusttothepeakflowperiod,sosummerdredgingintheColumbiaRiverdoesnotoccurtooearly(whileshoalsarestillshifting)ortoolate(afterriverlevelsdrop).Thesedredgingpracticeswillcontinuetomaximizetheefficientuseofavailableequipment.

18

Figure6‐2:O&M+Construction(NewWork)DredgingQuantities(1986‐2016)

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

ColumbiaRiverDredging(O&MandConstruction)CYbyYear:1986to2016

Actual 40‐ft Channel O&M (1986‐2004) = annual average 6,800,000 CY

Actual 43 ft Channel construction (2005‐2010) O&M plus New Work = annual average 7,600,000 CY

Actual 43 ft Channel construction (2005‐2010) O&M Only for comparison = annual average 4,500,000 CY

Actual 43‐ft Channel O&M (2011‐2016) = annual average 6,500,000 CY

Planned (CRCIP 2003 SEIS) 43‐ft Channel O&M (2011‐2016) for comparison = annual average 6,600,000 CY

19

6.2.3 ForecasteddredgingneedsThe2003ColumbiaRiverChannelImprovementProject(CRCIP)FinalSupplementalIntegratedFeasibilityReportandEnvironmentalImpactStatementpredictedthatanaverageof4.6mcywouldbedredgedannuallytomaintainthe43ftchannelovera20yearperiod(2011‐2030).Thisaveragedredgingneedwasbasedontwoassumptions:thatanannualaverageofnearly3mcy(63%)wouldbeplacedupland,andthattheremovalofdredgedmaterialfromtheriverwouldconsequentlydecreasethevolumeofshoaling(dredgingneed)overtime.Theremainingannualaverageof1.7mcy(37%)wouldbeplacedin‐water.

However,actualuplandandin‐waterplacementvolumesfor43ftchannelO&Mfrom2011‐2016arenotconsistentwithplanned(CRCIP2003SEIS)volumes.Actualuplandplacementvolumesaremuchless(annualaverageofonly0.75mcy;12%ofthematerialdredged)andactualin‐waterplacementvolumesaremuchgreater(annualaverageof5.2mcy;80%ofthematerialdredged).Instead,theactualplacementvolumesfor43ftchannelO&Mfrom2011‐2016areclosertotheactualplacementvolumesfor40ftchannelO&Mfrom1986‐2004,whenanannualaverageof1.1mcywasplacedupland(16%ofthematerialdredged)andanannualaverageof4.7mcywasplacedin‐water(69%ofthematerialdredged).

Becausefuturedredgingneedisbasedlargelyonthevolumeofmaterialremainingintheriversystem,itfollowsthatfuturedredgingneedsfor43ftchannelO&Mwouldbesimilartoannualaveragesfor40ftchannelO&M,insteadoftheCRCIP2003SEISprediction.Forthepurposesofthisassessment,theforecastedaverageannualdredgingneedforthenext20yearsisexpectedtobe6.5mcy(130mcytotal)andincludesallplacementoptions.Thisforecastisconsistentwiththehistoricsustainedaveragefor40ftchannelO&M(1986‐2004),thecurrentaveragefor43ftchannelO&M(2011‐2016),andsupportedbycurrentchannelconditionreports.TheseforecastednumbersincludeAMDthatwillhelpmaintainchannelstabilityandlimitfuturedraftrestrictions.

RiverTrainingStructures

6.3.1 PiledikesPiledikes(SeeFigure6‐3)arethemostcommonhydrauliccontrolstructureusedbytheCorpsPortlandDistrictintheColumbiaRiver.Piledikesaresemi‐permeablegroinsconsistingoftworows(riverine)orthreerows(estuary)ofuntreatedtimberpilingsdrivenon2½footcentersalternatelyplacedoneachsideofhorizontalspreaderpiles,whichareboltedinplace.Stoneisplacedalongthepiledikeandaroundtheouterendforprotectionfromscour.Atypicalpiledikeaveragesabout400ftwithhundredsofpilings.Piledikesystemsconsistofaseriesoftimberpiledikes,generallyspacedabout1200‐1500ftapartforoptimumfunctionalefficiency.Piledikestypicallyrunperpendiculartothedirectionofflowandareanchoredintoashoreline.Piledikesfunctiontoslowtheflowofwateratthe

20

edgesofthechannel,therebyacceleratingitintothecenterofthechannel.Piledikesareusedtocontrolchannelalignmentfornavigation,reducecross‐sectionalareaandfocusflowintothenavigationchanneltohelpmaintainauthorizeddepthsbynaturalscouringaction,providebankprotectionbyreducingbankerosion,andprovidestableareasfordredgedmaterialplacement(AECOM,2011).

Piledikeconstructionbeganin1885,butmostpiledikeswerebuiltbetween1917and1939.Thelastsignificantpiledikeadditionswerebuiltduringconstructionofthe40ftchannelinthe1960'stofurtherconstrictflowandreduceerosionatdredgedmaterialplacementsites.Thepiledikesystemsprotectmanymillionsofcubicyardsofdredgedmaterialfromerosion.Thepiledikesystemsweredesignedtofunctioninafluvialregimethathaschangedsignificantlysincetheirinitialconstructionwiththeadditionofflowregulationactionsinthesystem.Theauthorizedchanneldepthshavealsochangedovertimefrom35ftin1935to40ftin1962andmostrecentlythecurrent43ftauthorizeddepthasachievedin2010.Thesechangesmayproducehydrauliceffectsthatexceedthecapacityofthepresentpiledikestofunctionasintended.

Figure6‐3:TypicalPileDikeStructureinLowerColumbiaRiver

21

Ofthe236piledikesconstructedbytheCorpsintheColumbiaRiver,201arewithinthisstudyarea.Ofthe201piledikesintheLowerColumbiaRiver,76areconsideredtobeinpoorstructuralcondition,and12piledikeswereeithernotfoundorareinastateofsubstantialdeterioration(AECOM,2011).Therearesignsoffunctionalfailuresuchasincreasedbankerosionandshiftingchannelalignmentinsomelocations.Ifthesestructuresarenotrepairedpriortolosingfunctionality,thedredgingneedisexpectedtoincrease.Functionalpiledikesarecriticalforcontinuednavigationchannelmaintenance.TheDMMPwillsupportprioritized,programmaticpiledikerepaireffortsbydetermininghowtheserepairsfitintotheoverallplanforthenext20yearsofchannelmaintenance.Thepiledikesareassumedtohaveacurrentlevelofreducedfunction,andtheassumptionoffuturepiledikerepairswillguidehowtheDMMPistodevelopalong‐termchannelmaintenancestrategy.The2011analysisofpiledikesalsoidentifiedpotentialopportunitiesforhabitatimprovementsuchasplacingdredgedmaterialaroundexistingpiledikestoimprovehabitatdiversity.

6.3.2 DredgedmaterialfillDredgedmaterialhasalsobeenusedintentionallytomaintainthenavigationchannelbyreducingrivercross‐section(placingfillinshallowwaternearthebankswhichincreasesvelocitiesinthenavigationchanneltocreatenaturalscouringaction)andtocontrol

22

channelalignment(byredirectingflow).Inmanycases,theserivertrainingfillsiteswereconstructedalongwithpiledikestoprotectthedredgedmaterialfromerosion.ExamplesofislandsbuiltorexpandedtoimprovechannelmaintenanceincludeRice,MillerSandsSpit,PillarRock,Tenasillahe,Coffeepot,Brown,Crims,Hump,Lord,Howard,Sandy,Goat,andSandIslandnearSt.Helens.HenriciBarisagoodexampleofthesuccessfuluseofrivertrainingstructureswhereFNCdepthsincreasedbyupto20feet(combinationofpiledikesanddredgedmaterialfill).Before(1909)andafter(1959)resultsoftrainingstructuresatHenriciBarareshowninFigures6‐4and6‐5.

Figure6‐4:HenriciBar–rivertrainingusingpiledikesanddredgedmaterialfillColumbiaRiverShipChannelImprovementandMaintenance(Hickson,1961).

Figure6‐5:HenriciBar–rivertrainingusingpiledikesanddredgedmaterialfillColumbiaRiverShipChannelImprovementandMaintenance(Hickson,1961).

Withoutfunctionalpiledikesupportand,ifneeded,supplementarydredgedmaterialfill,theserivertrainingsitescoulderodeandshiftlocation,whichwillincreasemaintenancedredgingneeds.Thecurrentconditionofrivertrainingfillsiteshasnotbeenevaluated.

Assessmentofneedsforthenext20yearsAnestimatedaverageof6.5mcyofdredgedmaterialisprojectedtoberemovedannually(130mcytotal)inordertomaintaintheLowerColumbiaRiverFNCthroughthedurationofthis20yearplan.Thisestimateisbasedonthehistoricsustainedaverageforthe40ftchannel(1986‐2004),currentaveragemaintenanceafter43ftchanneldeepening(2011‐2016),andsupportedbycurrentchannelconditionreports.However,6.5mcyisanaverageandexperienceindicatesthatannualdredgingneedswillfluctuatehigherorlowerdependingonvariousfactorsthatinfluenceshoalingconditions,includingpeakriverflowandamountofAMD.TheDMMPwillcontinuetolookforwaystoimprovecurrentdredgingpractices.

23

SandwavesareachronicshoalingproblemfortheColumbiaRiverandalternativetechniquesforaddressingsandwaveshoalingneedtobefurtherinvestigated.Sandwavedredgingisinefficient,evenforhopperdredges,andbecausesandwavesmoveandgrowcontinuously,itwouldbeusefultohaveaccesstoadditionaldredgingequipmentdesignedspecificallytoclearsandwaveshoalsmoreefficientlyortoclearsandwaveshoalswhentheotherdredgesarenotimmediatelyavailable.Thelackofdredgingrequiredbetweenthewaves(wherematerialisbelowauthorizedandAMDdepth)createsinefficientdredging.The2013ValueEngineeringStudy:ProgrammaticProjectDredging‐VariousCorpsPortlandDistrictLocationsrecommendsuseofatowanddragbeamforlevelingsandwavesintheColumbiaRiver.Theideaisthatthetowanddragbeamwouldsupplementexistingdredgingequipmenttoclearshoalingfasterandmoreefficiently.However,thistechniquehasnotbeenpreviouslyappliedtocoursegrainedsandwavesintheColumbiaRiver.FurtherliteratureresearchandanalysisisneededtodetermineifthismethodisphysicallycapableofandcosteffectiveforclearingsandwaveshoalingtoauthorizeddepthintheLowerColumbiaRiverFNC,andtounderstandtheenvironmentalimpacts.Ademonstrationprojectmaybewarranteddependingontheoutcomeoftheresearchandanalysis.

Piledikesystemsthroughouttheprojectareawillneedtobeeitherrepairedorreplacedduringthe20‐yearDMMPperiodinordertomaintainfunctionundercurrentconditions.Dredgedmaterialmayneedtobeaddedtoexistingrivertrainingfillsitestorestoreerodedareasinordertomaintainfunction.Thecurrentinventoryandconditionofrivertrainingfillsitesmustfirstbedetermined.

The2013ValueEngineeringStudyalsorecommendsstudyingchannelmodifications,additionalhydrauliccontrolstructureopportunities,andotherengineeringpracticesasidentifiedthroughplanformationtoalterflow,preventsandwaveformation,andimproveoverallchannelconditions.

24

7 DredgedMaterialPlacementAssessment

IntroductionMaterialplacementmethodsandlocationsarestrategicallybalancedtominimizefutureshoalingandColumbiaRiverFNCO&Mdredgingneedswhilealsomaintaininganavailablesedimentbudgetfortheriversystemecology.Otherfactorsthatdeterminehowmaterialisplacedincludetheproximityofplacementlocationstodredgingareasanddredgeequipmentcapabilitiesandlimitations(forinstance,thepipelineDredgeOREGONisbestequippedforuplandplacementbutifthereisnotanuplandplacementsitewithinphysicalpipelinelengthofthedredgingarea,in‐waterplacementistheonlyoption).Managementofdredgedmaterialisalsodependentongeographicandtemporalvariabilityofshoaldevelopment.ThematerialbeingdredgedfromtheLowerColumbiaRiverFNCiscleansand,whichallowsforacombinationofupland,shoreline(beach),andopenwaterdredgedmaterialplacementmethodstobeused(seeFigure7‐1).

Uplandandshorelineplacementareasarewelldefined(seeFigure7‐2),whilelocationsforin‐waterplacementintheColumbiaRivervarydependingontheconditionofthechanneleachyear.Inmostcases,whendredgedmaterialisplacedin‐wateritisnotintendedtobemovedagainbydredges.Instead,asdeeperareasintheriverarefilledwithdredgedmaterialovertime,newdeepareasareformedelsewhereasaresultofnaturalriverprocesses.However,insomecaseswhereshoalsarelocatedtoofarfromanuplandsitefordirectplacement,dredgedmaterialmaybetemporarilyplacedin‐waternearbytoclearshoalingquicklyandthenrehandledbyanotherdredgetotheuplandsite.Nearthoseuplandsites,adredgecreatesatemporarysumpwhichisadeeperareaoftheriverbottomoutsideofthemainchannelfortemporaryin‐waterplacementofdredgedmaterialandstoragebeforethatplacedmaterialispumped(rehandled)intotheuplandsite.Placementatdesignatedoceansitesisalsoallowedandmaybeneededinthefuturetoensureabalancedapproachtochannelmaintenanceascapacitiesofothersiteschangeovertime.UtilizationoftheoceanplacementsitesformaterialfromtheLowerColumbiaRiverFNCislessefficientandmoreexpensivebecausematerialmustbetransportedasignificantdistancefromthedredginglocationouttothedesignatedoceansites.

Theremaybemorethanoneplacementoptionforagivendredgingevent.Placementsiteselectionconsiderationsincludedredgeequipmentcapabilities,distancefromthedredginglocation,cost,remainingsitecapacities,competingplacementneedsofotherdredgingeventsthatareongoingorplanned,andhowitwillcontributetooverallprojectstrategies.

ThepurposeofthissectionistosummarizeandevaluatetherecenthistoryandcurrentconditionofdredgedmaterialplacementcapacityintheColumbiaRiverFNCtounderstandanylargersystemconstraintsondredgingandplacementandassesspotentialimpedimentstocontinuedFNCoperationsandmaintenance.

25

Figure7‐1:RecentDredgedMaterialPlacementbyMethod(2014‐2016)

72% ‐ 5.6 mcy 69% ‐ 3.9 mcy80% ‐ 4.4 mcy

9% ‐ 0.7 mcy  14% ‐ 0.8 mcy

8% ‐ 0.7 mcy

19% ‐ 1.5 mcy 17% ‐ 1 mcy12% ‐ 0.5 mcy

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2014 ‐ 7.8 mcy 2015 ‐ 5.7 mcy 2016 ‐ 5.6 mcy

Recent Dredged Material Placement by Method

In‐Water Shoreline Upland

26

Figure7‐2:LowerColumbiaRiverUplandandShoreline(Beach)PlacementAreas

27

UplandPlacement

7.2.1 HistoricaluplandplacementevaluationFigure7‐3showsuplandplacementvolumesfortheperiod1986to2016.

TheCRCIP2003SEISpredictedthattheannualaverage43ftchannelO&Muplandplacementfor2011‐2016wouldbe4mcy,whichwasnearly4timesgreaterthantheannualaverageof1.1mcyofuplandplacementduring40ftchannelO&M.However,itdidnotconsiderthedredgeequipmentavailablefor43ftchannelO&M,whichhasbeenunabletoachievetheincreasedvolumeofuplandplacement.ThepipelinedredgeOREGONcancosteffectivelyplacematerialupland,butonlywherethedistancebetweenshoalingandavailableuplandplacementsitesdoesnotexceedthephysicalpipelinelength.Ittakesapproximatelytwiceaslongforahopperdredgetoclearashoalwhenmaterialispumpedupland,comparedwithin‐waterplacement,atasignificantlyhighercost.Becausehopperdredgesareneededtoremoveshoalsquickly,ithasnotbeenfeasibleforhopperdredgestoplacematerialuplandduring43ftchannelO&M.

Asaresult,theannualaveragevolumeof750kcyplaceduplandduring43ftchannelO&M(2011‐2016)isjust19%ofthe4mcythatwasplannedintheCRCIP2003SEIS.Asstatedearlier,thisisconsideredtobeoneofthereasonswhyfutureO&MdredgingneedsareexpectedtobegreaterthanthoseplannedintheCRCIP2003SEIS.

28

Figure7‐3:UplandPlacementQuantities(1986‐2016)

Note:Nouplandplacementoccurredin1988,1989or2003.

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

4,500,000

5,000,000

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

ColumbiaRiverUplandPlacementCYbyYear:1986to2016

Actual 40‐ft Channel O&M (1986‐2004) = annual average 1,100,000 CY

Actual 43 ft Channel construction (2005‐2010) O&M plus New Work = annual average 2,000,000 CY

Actual 43‐ft Channel O&M (2011‐2016) = annual average 750,000 CY

Planned (CRCIP 2003 SEIS) 43‐ft Channel O&M (2011‐2016) for comparison = annual average 4,000,000 CY

29

7.2.2 ForecasteduplandplacementneedsOverthenext20years,approximately6.5mcyofmaterialisexpectedtobedredgedfromtheLowerColumbiaRiverFNCannually,butuplandplacementcapacityisonlyneededforaportionofthistotal.AssuminguplandplacementwillcontinuetobeachievedsolelybythepipelinedredgeOREGON,anestimated1‐2mcyofmaterialcouldbeplacedatuplandsiteseachyear.Thelowernumberintherangeisbasedon43‐ftChannelO&Myears2013‐2016,whenanaverageof1mcyofdredgedmaterialwasplacedupland,andthe40ftchannelO&Maverageof1.1mcy(1986‐2004).ThehighernumberintherangeispossibleifagreaterpercentageofthetotalannualdredgingvolumeofthedredgeOREGONwasplacedupland.Therefore,inordertocontinuethestrategyofbalanceddredgedmaterialplacementforthis20yearperiod,if1‐2mcyofmaterialcouldbeplaceduplandeachyear,anestimated20‐40mcyoftotaluplandcapacityisneeded.Additionalrehandlesumpsmaybeneededaswell,forthoseuplandsiteswherethedistancetothenearestshoalexceedsthephysicalpipelinelengthofthedredgeOREGON.

7.2.3 RemaininguplandplacementcapacityTheestimatedcapacityremainingatexistinguplandplacementsitesafter2016is16.75mcy(seeTable7‐1).Additionally,thirteenofthenineteensitesarealreadyfullorhavecapacityforjustoneortwomoreplacementevents.Manyoftheselimitedcapacitysitescouldbefullwithinthenextfiveyearsandthemajorityofsitesareexpectedtobecomeunusableoncefilled.Therearecurrentlysandresaleoperationsatfivesitesthatcouldrestorecapacityovertime;however,becauseresaleoperationsarenotunderthefederalgovernment’scontrol,thecontinuationandpredictabilityoffutureoperationsarenotcalculable.ItisalsoimportantthatuplandcapacitymustbedistributedwhereneededthroughouttheentiretyoftheLowerColumbiaRiverFNC(RM3toRM105.5)overthis20yearperiod.

Table7‐1:UplandPlacementCapacity(ColumbiaRiverFederalNavigationChannelInterimOperations&Maintenance(O&M)Plan,revisedtoreflectactualplacement2014‐2016)

DredgedMaterialPlacementSite

State(WA,OR)‐RiverMile

Remainingcapacityendof2016

Remainingplacementevents(approx.)

Critical statuswithin5years

RiceIsland W‐21.0 2,550,000 8 PillarRockIsland O‐27.2 2,000,000 5 WelchIsland O‐34.0 400,000 2 FullTenasillaheIsland O‐38.3 300,000 1 FullJamesRiver O‐42.9 1,350,000 4 PugetIsland W‐44.0 2,200,000 5 BrownIsland W‐46.3 700,000 2 FullCrimsIsland O‐57.0 550,000 2 1eventremainHumpIsland W‐59.7 600,000 2 1eventremainLordIsland O‐63.5 400,000 2 1eventremainDibbleePoint O‐64.8 0 0 Full

30

DredgedMaterialPlacementSite

State(WA,OR)‐RiverMile

Remainingcapacityendof2016

Remainingplacementevents(approx.)

Critical statuswithin5years

HowardIsland W‐68.7 2,500,000 10 CottonwoodIsland W‐70.1 250,000 1 FullSandyIsland O‐75.8 0 0 FullLowerDeerIsland O‐77.0 450,000 2 1eventremainMartinBar W‐82.0 300,000 1 FullAustinPoint W‐86.5 300,000 1 FullGateway W‐101.0 600,000 2 1eventremainWestHaydenIsland O‐105.0 1,300,000 4

ShorelinePlacement

7.3.1 Historicalshorelineplacementevaluation 

Figure7‐4showsshorelineplacementvolumesfortheperiod1986to2016.

Shorelineplacementvolumesforthe43ftchannelarelessthanhalfofthe40ftchannelO&Maverage.Inresponsetoadditionalenvironmentalrestrictionsonshorelineplacementandchangesindredgingneedandequipmentovertime,thenumberofsitesavailablehasbeenreducedfrom80in1975to14in1993andto3intheCRCIP2003SEIS.Currently,onlythepipelinedredgeisequippedforshorelineplacement.

Average43ftchannelO&Mshorelineplacementisconsistentwithwhatwasplanned.

31

Figure7‐4:ShorelinePlacementQuantities(1986‐2016)

Note:Noshorelineplacementoccurredin1986,1987,2001or2003.

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

4,500,000

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

ColumbiaRiverShorelinePlacementCYbyYear:1986to2016

Actual 40‐ft Channel O&M (1986‐2004) = annual average 1,000,000 CY

Actual 43 ft Channel construction (2005‐2010) O&M plus New Work = annual average 400,000 CY

Actual 43‐ft Channel O&M (2011‐2016) = annual average 550,000 CY

Planned (CRCIP 2003 SEIS) 43‐ft Channel O&M (2011‐2016) for comparison = annual average 450,000 CY

32

7.3.2 ForecastedshorelineplacementneedsTherecurringneedfordredgingatshoalsadjacenttoexistingshorelineplacementsitesisexpectedtocontinueatfrequenciesandquantitiesthatareconsistentwithrecentyears.However,additionalshorelineplacementcouldbeusedasrivertrainingfilltoimprovechannelmaintenanceandbalancebetweenplacementmethods.Inordertomaintainandpossiblyincreasethecurrentshorelineplacementamounts;theDMMPneedstoidentifylocationsthroughoutthesystemthatcanaccommodate500kcyto1mcyofdredgedmaterialor10‐20mcyoverthenext20years.

7.3.3 RemainingshorelineplacementcapacityTherecurringcapacity(timingandvolume)restoredbynaturalerosionofexistingshorelineplacementsites(andsandresaleoperationsatSkamokawa‐VistaPark)isgenerallywellbalancedwiththeneedfordredgingatshoalsadjacenttothosesites.Thistrendisexpectedtocontinueoverthenext20years.Inotherwords,theexistingsitesarebeingfullyutilizedandthereisnocapacityfordredgedmaterialfromadditionalshoalsthatwouldotherwisebeplaceduplandorin‐water.TheprimaryshorelineplacementsitesarelistedinTable7‐2,althoughshorelineplacementisalsopermittedtorestoreerodeduplandareasneededforcapacityatRiceIsland(W‐21.0)andPillarRockIsland(O‐27.2).

Table7‐2:ShorelinePlacement Sites

DredgedMaterialPlacementSite RiverMile

MillerSands O‐23.5Skamokawa‐VistaPark W‐33.4SandIsland O‐86.2

OpenWaterPlacement

7.4.1 HistoricalopenwaterplacementevaluationTherearetwotypesofopenwaterplacement:in‐waterplacementintheColumbiaRiverandatdesignatedoceandisposalsites.MostmaterialdredgedfromtheFNCduringtheperiodfrom1986to2016hasbeenplacedbackintotheriver.Thissectionfocusesondredgedmaterialthatisplacedbackintotheriver,remainsintheriver,andissubjectedtonaturalriverineprocessesovertime.Oceandisposalwasusedbrieflyduringconstructionofthe43ftchannel,buthasnotyetbeenusedformaterialdredgedfor43ftchannelO&Mbecausetheotherplacementmethodscombinedhavehadsufficientcapacityandaremoreefficientandlesscostlythanlonghaulsouttosea.

Figure7‐5showsin‐waterplacementvolumesfortheperiod1986to2016.

33

Theannualaveragevolumeofdredgedmaterialplacedin‐waterduring40ftchannelO&Mfrom1986to2004was4.7mcy.TheCRCIP2003SEISpredictedthattheannualaverage43ftchannelO&Min‐waterplacementfor2011‐2016wouldbe2.2mcy,lessthanhalfofthehistorical40ftchannelO&Mvolume.ThereasonforthedifferenceisthattheCRCIP2003SEISplannedforagreaterpercentageofdredgedmaterialtobeplaceduplandinsteadofin‐water.However,itdidnotconsiderthedredgeequipmentavailablefor43ftchannelO&M,whichhasbeenunabletoachievetheincreasedvolumeofuplandplacement.Instead,theactualaverageannualin‐waterplacementvolumefor43ftchannelO&Mduringtheyears2011‐2013wasabout6mcy.Mostrecently,during2014‐2016,theaverageannualin‐waterplacementvolumefor43ftchannelO&Mwas4.7mcy,whichisthesameasthehistoricalaveragefor40ftchannelO&M.

Locationsforin‐waterplacementmustbeselectedcarefullytominimizeshoalingofplacedmaterialbacktothechannel,whereitwillneedtobedredgedagain.In‐waterplacementsitesarenotdesignatedpermanentlybutinsteadchosenforeachdredgingeventbasedondepthsfromrecentsurveysoftheriverbottomoutsidethenavigationchannel.During40ftchannelO&M,materialwasgenerallyplacedinthenearestflow‐laneareainandadjacenttothechannelatdepthsof35‐65ft,tomaximizedredgingefficiency.Itwasacceptableforplacedmaterialtoaccumulateinthechannelaslongasitdidnotbecomeshallowerthantheadvancedmaintenancedepthof45ftsoitwouldnotgrowtoshoalingabovetheauthorizedchanneldepthof40ft.Nowthatthechannelismaintainedto43ftwithadvancedmaintenanceto48ft,placingmaterialwhereitcouldaccumulateto45ftinthechannelconflictswithadvancedmaintenanceneedsandisnolongeracceptablesothereislesscapacityintheriverforin‐waterplacement.Also,increasedshoalingwasobservedatcertainlocationsdownstreamofin‐waterplacementsitesusedforinitial43ftchannelO&M,raisingconcernsabouttheefficiencyoftheoveralldredginganddredgedmaterialplacementapproach.

In‐waterplacementoptionsarealsolimiteddependingondredgeequipment.AllmaterialdredgedbyhopperdredgesforO&Mofthe43ftchanneltodatehasbeenplacedin‐waterindepthsgreaterthan20ft.Thesmallesthopperdredge(YAQUINA)cansafelyaccessdepthsasshallowas20ft,butlargerhopperdredgescanonlysafelyaccessdepthsgreaterthan30or35ft.Thepipelinedredgealsoplacesmaterialin‐wateratcertainshoalswhereotherplacementoptions(uplandorshoreline)arenotavailable.Adownspoutisusedsothedischargefromthepipelinedredgeisgreaterthan20ftbelowthesurfaceofthewater,generallyinareaswheretheriverbottomisgreaterthan30to35ftdeep.

Toaddressthesein‐waterplacementcapacitychallenges,CorpsPortlandDistricthydraulicengineerswereaddedtothetechnicalteamin2012toconsultonin‐waterplacementlocationsandoperations.Ahydrodynamicmodelwasusedtoexaminecurrentsanddepthsandselectsitesandplacementmethodstominimizeand/ordelaythereturnofplacedmaterialtothechannel.Thefindingsofthateffortjustifiedhaulingmaterialmuchfarther

34

downstream(vs.ashorthaulupstream)atmorethanonecriticalshoalandchangedin‐waterplacementpracticesatseveralreachesfromplacingalargeamountofmaterialinasingle,erosive,deepwatersitetoplacingmaterialinthinlayersoverseveral,stable,shallowerwatersites.

Recently,someareastraditionallyusedforin‐waterplacementhavebecomeinformalshipanchorageareas.Thishasrestrictedtheuseofthoseareasforin‐waterplacementintwoways:first,dredgescannotaccesstheareawhenthereisashipatanchorandsecond,dredgedmaterialaccumulationislimitedtothewaterdepthneededforshipstoanchorsothereislesscapacityforin‐waterplacement.

35

 Figure7‐5:In‐WaterPlacementQuantities(1986‐2016

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

9,000,000

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

ColumbiaRiverIn‐WaterPlacementCYbyYear:1986to2016

Actual 40‐ft Channel O&M (1986‐2004) = annual average 4,700,000 CY

Actual 43 ft Channel construction (2005‐2010) O&M plus New Work = annual average 4,600,000 CY

Actual 43‐ft Channel O&M (2011‐2016) = annual average 5,200,000 CY

Planned (CRCIP 2003 SEIS) 43‐ft Channel O&M (2011‐2016) for comparison = annual average 2,200,000 CY

36

7.4.2 ForecastedopenwaterplacementneedsOpenwaterplacementmethodisexpectedtocontinuetobeusedforallofthematerialdredgedbyhopperdredgesbecauseoftheirequipmentcapabilitylimitationsandlowcostforin‐waterplacement.Itisthereforeassumedthattheneedforopenwaterplacementwillcontinueatthecurrentrate(consistentwithhistoricalaverage)of4‐5mcyor80‐100mcyforthenext20years.Evenwiththeadditionalhydraulicanalysistooptimizein‐waterplacementsites,thesustainedvolumeofin‐waterplacementwillstillaffectshoalinginthechannelovertime.Thebestwaytominimizeshoalingisthroughinformedandstrategicdecisionmaking.TheCorpsPortlandDistrictneedstoupdatetheirhydraulic,sedimenttransport(mobilebed)andparticletrackingmodelsinordertodeterminethebestin‐waterplacementpracticesmovingforward.TheCorpswillalsoseekincreasedadaptabilityforenvironmentalcoordinationtogainaccesstosuitablelocationswherein‐waterplacementofdredgedmaterialcanoccurinwaterdepthsoflessthan20ft.Thiswouldprovideforincreasedin‐waterandshorelineplacementvolumecapacitywhileenablingtheenhancementofrivermorphologywithintheLowerColumbiaRiver.

7.4.3 RemainingopenwaterplacementcapacityItischallengingtoquantifyremainingin‐waterplacementcapacityintheColumbiaRiverbecauseitvariesdependingontheconditionofthechanneleachyear(asdeeperareasarefilledwithdredgedmaterial,newdeepareasareformedelsewhereasaresultofnaturalriverprocesses).However,therearestrongindicationsthatin‐watercapacityforthe43ftchannelisbecomingincreasinglylimited.Thefirstindicationisthatbecauseofdredgedmaterialaccumulation,manyoftheideal,stablein‐waterplacementareasusedfor43ftchannelO&Marenowtooshallowforlargerhopperdredges.Conditionsurveysin2016didnotshownewideal,stableareasformingelsewheretoreplacethosethatarenowtooshallow.Instead,dredgedmaterialfromlargerhopperdredgeswillincreasinglybeplacedinlocationsthatarelessstablesoplacedmaterialismorelikelytobetransportedbackintothechannelasfutureshoaling.Also,insomelocations,materialplacedin‐waterisalreadyshoalingbackintothechannel,whichsuggeststhatthosesiteshavereachedcapacityandrendersthemunsuitableforfutureplacement.

Oceandisposalsites,availableformaterialdredgeddownstreamofRM30,areassumedtohave14mcyofcapacityremaining(2mcyusedfor43ftchannelconstructionofthe16mcyplannedforconstructionandfirst20yearsofmaintenanceinthe1999CRCIPFeasibility/EIS&interimO&MPlan).

RegionalSedimentManagement(RSM)AnothergoaloffuturechannelmaintenanceplanningintheCorpsPortlandDistrictistocontinueutilizingandbuildinguponRegionalSedimentManagement(RSM)‐informeddecisionmaking.RSMisasystemsapproachtodeliberatelymanagesedimentsinamannerthatmaximizesnaturalandeconomicefficienciestocontributetosustainablewater

37

resourceprojects,environments,andcommunities.WithinanRSMframework,sedimentisviewedasanaturalresourcetobeconservedwithinthesystemthatsedimentisactive.RSMfosterssustainablebalancebetweenprojectsandnaturalsystemprocesses:Theobjectiveistoreduceprojectcostsandachievegreaterbenefits.RSMbroadensthe“planninghorizon”forprojectsbyconsideringtheextendedtime‐spacescaleasdefinedbynaturalsedimentprocesses.WithinaDMMP,RSMcanlinkdredging(anddredgedmaterialplacement)projectswithina“Region”andrequiresfullcollaborationamongagencies,levelsofgovernment,andstakeholders.RSMprovidesopportunitiestoimproveenvironmentalhabitatwhileoptimizingtheuseofsediments.

In‐waterplacementandshorelineplacementstrategiesareessentialformaintainingtheriver'smorphology.Thepresentrivermorphology(sedimentshoals,islands,andriverbanks)actstostabilizethethalweg,provideasustainableFNC,andprovideforecologicalsubstrate.In‐waterplacementandshorelineplacementstrategieswereusedprominentlyinthepasttodevelopthepresentLowerColumbiaRivermorphologythatenableddevelopmentoftheFNC.ThesestrategieswillneedtobeusedinasimilarmannertosustaintheFNCintothefuture,astheFNChasbeenrecentlydeepened.Over‐relianceonuplandplacementcannegativelyaffecttheLowerColumbiaRivermorphology,whichcouldjeopardizeFNCsustainabilityandtheenvironment.

Assessmentofneedsforthenext20yearsThe40ftchannelO&Mandplansfor43ftchannelConstructionandO&Mconsidereduplandplacementtobebeneficialbecauseitremovesmaterialfromthesystemsoitisnolongerasourceforshoaling.However,subsequentresearchbyDavidJay,ProfessorPh.D.inPhysicalOceanographyatPortlandStateUniversity,suggeststhatlong‐termuplandplacementmayactuallycontributetolowerwaterlevelsfornavigation(Jay,2013).Forinstance,thelossofsedimentfromuplandplacementcouldresultindeeperriverbottomconditionsbetweenriverbanks;then,inconcept,assumingthesamequantityofriverflowcrosssectionalarea,theactualcrosssectionofwaterwouldshiftlowerintothedeeperriverbottomconditions,whichwouldconsequentlylowerthewatersurfacelevel.Uplandplacementneedstobefurtherinvestigatedtodeterminewhatthelong‐termplanshouldbe.

Thisassessmentassumesanestimatedannualaverageof1‐2mcyofuplandplacementoverthedurationofthis20yearplan(totalestimated20‐40mcyofuplandcapacity).Thisvolumeisintendedtoprovideabalancingstrategyformaintainingin‐waterplacementcapacityoverthelengthoftheplan.Tomeetthisneed,anestimated10‐20newuplandplacementsitesshouldbeidentifiedwithintheLowerColumbiaRiverprojectarea.Basedonlessonslearnedfrompastchannelmaintenanceplansandpractices,theCorpswillseekmultipleuplandplacementopportunitieswithinthemostcommonlydredgedreachesoftheLowerColumbiaRiver.

38

Inadditiontoidentifyingnewuplandplacementsites,theplanwilllooktoextendthelifeofcurrentuplandsitesthatarereachingcapacity.Thiscanbedonethroughsandremovaloperationsorbyexpandingthesizeofcurrentuplandsiteswithinthesystem.TheteamwillalsoperformadvancedvolumeanalysisoncurrentuplandsitesusingLIDARdatatogetmoreprecisecapacitycalculations.

TheDMMPshouldcalculatethesustainablerateofuplandplacementthatcanberealized(perriverreach),withoutnegativelyaffectingtheLowerColumbiaRiversedimentbudgetormorphology.Also,theplanneedstodevelopavisionforwhattherivermorphologyneedstobeinthefutureandhowtosustainthatmorphologyusingdredgedsediment,andtrainingstructureswhereneeded.TheLowerColumbiaRivermorphologyvisionisdirectlyassociatedwithRSM,andisexemplifiedinDr.DavidA.Jay’s2013presentationTheTrajectoryoftheLowerColumbiaRiverandEstuary,1850‐2013.

Additionalshorelineplacementsitesareneededtoprovidecapacityforthe10‐20mcyofdredgedmaterialthatisestimatedforthe20yeardurationofthisplan.Shorelineplacementisneededtosupporterodinguplandsitesandprovideplacementcapacitywhereuplandandin‐watersitesmaynotbeavailable.Shorelineplacementmayalsobeusedforrivertrainingtoimprovechannelmaintenance.

Improvementofin‐waterplacementtechniquesusinghydraulicanalysisisessentialtoproperlyaccommodatethe80‐100mcyofdredgedmaterialthatisprojectedtobeplacedin‐waterthroughoutthe20yeardurationofthisplan.DuringdevelopmentofthisDMMP,AdH(AdaptiveHydraulic)shallow‐waterhydrodynamicmodelandAdHsedimenttransportmoduleshouldbeusedtoanalyzepastin‐waterplacementpracticesandtomakerecommendationsmovingforward.

Astraditionalin‐waterplacementcapacitybecomesmorelimited,increaseduseoftemporaryin‐waterdredgedmaterialrehandlesites(foreventualuplandorshorelineplacement)shouldbeconsidered,i.e.sumps.Also,thereisadditional(untapped)capacityforshallowwaterplacementthatisnotbeingutilizedbycurrentdredgedmaterialplacementpracticesintherangeofdepthsbetweenshorelineplacementandin‐waterplacementdepthsof20ftorgreater.Modificationstodredgeequipmentandenvironmentalcompliancewouldberequiredtoplacematerialin‐wateratdepthsshallowerthan20ft.

Theplanshouldseektodefinesustainablethresholdsfortheratesatwhichin‐waterplacementsitescanbeexpectedtocontributetofutureFNCshoaling;basedontheneedtobalanceRSMconceptswiththeneedtoprovidereliabledeepdraftnavigationwithintheLowerColumbiaRiverFNC.Thequantityofdredgedmaterialplacedin‐waterthatisallowedtocontributetoFNCshoalingoverspecifiedperiodsoftime(1year,2years,etc.)shouldbecalculatedanddefinedwithineachmajormorphology‐hydrauliczone.

39

Considerationsincludecostanddredgeequipmentavailabilitytoremovetheforecastedvolumeofshoaling.

Inresponsetorecentincreasesinanchorageareasthatrestrictin‐waterplacementcapacity,theplanshouldresearchfuturetrendsinanchorageareasrequiredbychannelusers,aswellashowanchoragesanddredgedmaterialplacementwillco‐existoverthedurationoftheplan.

Onealternativetolongerhauldistancestoreachdeeperareasthatarefartherfromthedredginglocationcouldbehopperdredgelightloadingtoaccessshallowerwaterdepthsthatareclosertothedredgearea.Theplanshouldincludeastrategytooptimizein‐waterplacementbyconsideringthistrade‐off,whichcouldleadtomoreefficientandeffectivechannelmaintenancepractices.

Placementatdesignatedoceansitesisalsoallowedandmaybeneededinthefuturetoensureabalancedapproachtochannelmaintenanceascapacitiesofothersiteschangeovertime.Theplanmustconsideradditionaltimerequiredforlonghaulstooceansites.

ThemostcriticalconsiderationisthatdredgeequipmentavailabletotheprojectmustbeabletoimplementthestrategiesselectedundertheDMMPforupland,beachnourishment,andin‐waterplacementinorderforthemtobefeasible.TheteamwillneedtodetermineifitiswithinscopetoevaluatealternativedredgeequipmentaspartoftheDMMP.Also,thehopperdredgingfleetisagingandtherewilllikelybechangesduringthe20‐yearperiod.TheplanmustthereforeoptimizeandinformthecurrentandfuturedredgingfleetavailableforLowerColumbiaRiverFNCO&M.

40

8 RealEstate

Non‐FederalSponsorResponsibilitiesTheNon‐FederalSponsorsareresponsibleforacquiringalllands,easements,orrights‐of‐wayfordredgedmaterialplacementsitesthattheCorpsdeterminestoberequiredforProjectO&M,andshallperformorensureperformanceofallrelocationsthattheCorpsdeterminestobenecessary(ref:PCAArticleII,C).Further,theyareresponsibleforensuringthattheselands,easements,andrights‐of‐wayareretainedinpublicownershiporcontrolforusescompatiblewithauthorizedProjectpurposesforaslongasitremainsauthorized(ref:PCAArticleIII,A).Itisimportanttonotethatthedateofissuanceandexpirationofaneasementandaright‐of‐waycandifferfromeachotherforasingleproperty.

ExistingLands/Easements/Rights‐of‐WayThecurrentrealestatestatusislistedbyplacementsiteinTable8‐1,RealEstateSummary.Withtheexceptionofopenwaterareas,allexistingsiteshaverightsofentryfordredgedmaterialplacementthatwillexpirebeforetheendofthenext20yearchannelO&Mperiod.ThroughNavigationalServitude,thegovernmentmayutilizeopenwaterplacementareas.NavigationalServitudeisdescribedinER405‐1‐12(1May1998).“ThenavigationservitudeisthedominantrightoftheGovernmentundertheCommerceClauseoftheU.S.Constitution(U.S.Const.ArticleI,Section8,Clause3)touse,controlandregulatethenavigablewatersoftheUnitedStatesandthesubmergedlandsthereunderforvariouscommercerelatedpurposesincludingnavigationandfloodcontrol.Intidalareas,theservitudeextendstoalllandsbelowthemeanhighwatermark.Innon‐tidalareas,theservitudeextendstoalllandswithinthebedandbanksofanavigablestreamthatliebelowtheordinaryhighwatermark(OHWM)*.”

*OrdinaryHighWaterMark(OHWM)isdefinedat33CFR328.3(e)"Thetermordinaryhighwatermarkmeansthatlineontheshoreestablishedbythefluctuationsofwaterandindicatedbyphysicalcharacteristicssuchasclear,naturallineimpressedonthebank,shelving,changesinthecharacterofsoil,destructionofterrestrialvegetation,thepresenceoflitteranddebris,orotherappropriatemeansthatconsiderthecharacteristicsofthesurroundingareas.Provided,thatinanyareawheretheordinaryhighwatermarkcannotbefound,theordinaryhighwatermarkadjoiningsaltwatershallbethelineofmeanhigherhightideandtheordinaryhighwatermarkadjoiningfreshwatershallbethelineofmeanhighwater."

RefertotheColumbiaRiverFederalNavigationChannelInterimOperations&Maintenance(O&M)Planfordetailedinformationaboutrequirementsandresponsibilitiesforexistingeasementsandcoordinationrelatedtositeavailabilityandmaterialremovalprocedures.

41

Table8‐1:RealEstateSummary

Placement Site Name

WA or OR State side of Navigation Channel and River Mile Designation

State property is physically

located within

Property Name (if multiple)

Ownership Status

Easement from Owner Right of Entry to the Corps

Date Granted

Date Expires Acres Date

Issued Date

Expires

Remaining Years

(December 2016)

Rice Island W-21.0

OR - OR DSL 25 year easement 2/17/2005 2/17/2030 226.7 6/28/2006 2/16/2030 13

WA - WA DNR 30 year easement 10/26/2007 10/26/2037 37.3 10/27/2009 12/31/2037 21

Miller Sands O-23.5 OR - OR DSL 25 year easement 11/17/2005 11/17/2030 116.48 6/28/2006 11/16/2030 14

Pillar Rock Island O-27.2 OR - OR DSL 25 year

easement 2/17/2005 11/17/2030 51.59 6/28/2006 2/16/2030 13

Skamokawa - Vista Park W-33.4 WA - Port of

Wahkiakum II 20 year

easement 4/7/2016 4/6/2036 15.07 4/7/2016 4/6/2036 19

Welch Island O-34.0 OR - OR DSL 25 year easement 11/17/2005 11/17/2030 40.66 6/28/2006 11/16/2030 17

Tenasillahe Island O-38.3 OR - OR DSL 25 year

easement 2/17/2005 2/17/2030 40.57 6/28/2006 2/16/2030 13

James River O-42.9 OR - GP Consumer Products

20 year easement 10/17/2007 10/17/2027 53 10/17/2007 10/17/2027 11

42

Placement Site Name

WA or OR State side of Navigation Channel and River Mile Designation

State property is physically

located within

Property Name (if multiple)

Ownership Status

Easement from Owner Right of Entry to the Corps

Date Granted

Date Expires Acres Date

Issued Date

Expires

Remaining Years

(December 2016)

Puget Island W-44.0 WA

Vik Vik - - - 86.91 TBD - 0

Weeks Washington Ports Fee Title - - 5.86 3/25/2005 3/25/2025 8

Bacon Washington Ports Fee Title - - 0.59 12/23/2010 12/23/2030 14

Mickelson Washington Ports Fee Title - - 0.38 12/23/2010 12/23/2030 14

Whitney Washington Ports Fee Title - - 0.93 12/23/2010 12/23/2030 14

Schmuland Washington Ports Fee Title - - 1.28 3/25/2005 3/25/2025 8

Brown Island W-46.3 WA - WA DNR 30 year easement 10/26/2007 10/26/2037 102.1 8/14/2009 12/31/2037 11

Crims Island O-57.0 OR - OR DSL 25 year easement 2/17/2005 2/17/2030 58.82 6/28/2006 2/16/2030 13

Hump Island W-59.7 WA - WA DNR 30 year easement 10/26/2007 10/26/2037 64.57 8/14/2009 12/31/2037 11

Lord Island Upstream O-63.5 OR - OR DSL 25 year

easement 2/17/2005 2/17/2030 46 6/28/2006 2/16/2030 13

Dibblee Point

(Rainier Industrial)

O-64.8 OR - OR DSL 25 year easement 2/17/2005 2/17/2030 51.49 6/28/2006 2/16/2030 13

43

Placement Site Name

WA or OR State side of Navigation Channel and River Mile Designation

State property is physically

located within

Property Name (if multiple)

Ownership Status

Easement from Owner Right of Entry to the Corps

Date Granted

Date Expires Acres Date

Issued Date

Expires

Remaining Years

(December 2016)

Howard Island W-68.7 WA

Davis Washington Ports Fee Title - - 107.36 5/9/2013 5/9/2033 16

WA DNR WA DNR 30 year easement 10/26/2007 10/26/2037 153 5/4/2009 12/31/2037 21

Cottonwood Island W-70.1 WA - Washington

Ports Fee Title - - 654.17 8/15/2007 8/15/2027 11

Sandy Island O-75.8 OR - OR DSL 25 year easement 2/17/2005 2/17/2030 31.85 6/28/2006 2/16/2030 13

Lower Deer Island O-77.0 OR - OR DSL 25 year

easement 5/25/2005 5/25/2030 24.32 5/19/2006 5/24/2030 13

Martin Bar W-82.0 WA - Port of Woodland Fee Title - - 32 3/11/2005 3/11/2025 8

Sand Island O-86.2 OR - OR DSL 25 year easement 2/17/2005 2/17/2030 28.3 6/28/2006 2/16/2030 13

Austin Point W-86.5 WA - Port of Woodland Fee Title - - 26 3/11/2005 3/11/2025 8

Gateway W-101.0 WA - Port of Vancouver Fee Title - - 40 9/13/2005 9/13/2025 8

West Hayden Island

O-105.0 OR - Port of Portland Fee Title - - 116.3 3/9/2005 3/9/2025 8

Open-Water Placement*

Entire Project Area (O, W – 3-105.5)

OR and WA - OR DSL and

WA DNR NA NA NA NA NA NA NA

44

Assessmentofneedsforthenext20yearsAsdescribedabove,newsiteswillberequiredwithinthenext20yearstoprovidesufficientdredgedmaterialplacementcapacityforcontinuedchannelmaintenance.ThetimerequiredfortheNon‐FederalSponsorstoacquirelands,easements,andrights‐of‐wayisnotdefiniteandvariesbysite.Recently,theprocesstoacquiresomesiteeasementshastakenmanyyears.Therefore,thisDMMPmustallowreasonabletimefornewrealestateacquisitionsbasedonpreviousexperience.Additionally,challengessuchas:returnwateraccess,industrialdevelopments,sitecontamination,anddistancefromdredgingareas,preventedtheacquisitionofsitesaftertheywereselected,shouldbetakenintoaccountduringthedevelopmentoftheDMMP.Onemethodtohedgeagainstunforeseenobstaclestobringingnewplacementsitesonlinewouldincludeidentifyingadditional(substitute)siteoptionsifaprimarysitecannotbereasonablyacquired.TheDMMPshouldincludeaplanforrealestaterightsneededtoconductpiledikemaintenance.

9 EnvironmentalandGovernmentConsultationsandCompliance

ExistingEnvironmentalComplianceThissectionprovidesasummaryofexistingcompliancedocumentationforongoingProjectO&Mactivities.

CorpsProjectO&MactivitiesmustcomplywiththerequirementsofFederalenvironmentallawsandregulations.Thiscomplianceincludesevaluatingandminimizingprojecteffectsonphysical,biologicalandculturalresourcesandconsultingwithregulatoryagenciestoobtainapprovalsforprojectactions.Dredgedsedimentqualityisroutinelyevaluatedtomeetthecompliancerequirementsofmultipleenvironmentallawsandregulations.

AlistofexistingcompliancedocumentationpreparedorobtainedbytheCorpsforCorpsProjectO&MactivitiesisshowninTable9‐1,ExistingEnvironmentalComplianceSummary.ThesecompliancedocumentsareroutinelyrenewedbytheCorpsasneededtomaintaincompliance.

45

Table9‐1:ExistingEnvironmentalComplianceSummary.

Requirement Agency Compliance Document Date Issued Date Expires

Remaining Years (As of December

2016)

National Environmental Policy Act (NEPA)

Corps

Integrated Feasibility Report for Channel Improvements and Environmental Impact Statement (EIS)

Aug-1999 N/A N/A

Columbia River Channel Improvement Project Final Supplemental Integrated Feasibility Report and Environmental Impact Statement (SEIS)

Jan-2003 N/A N/A

Columbia River Navigation Improvement Project Record of Decision (ROD) 1/9/2004 N/A N/A

Columbia River Channel Improvement Project Supplemental Evaluation Aug-2008 N/A N/A

Caspian Tern Management to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary Final Environmental Impact Statement

Jan-2005 N/A N/A

Caspian Tern Management to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary Record of Decision

11/27/2006 N/A N/A

Columbia River Federal Navigation Channel Operations and Maintenance Dredging and Dredged Material Placement Network Update –Environmental Assessment

6/10/2014 N/A N/A

Columbia River Federal Navigation Channel Operations and Maintenance Dredging and Dredged Material Placement Network Update – Environmental Assessment

9/8/2015 N/A N/A

Fish and Wildlife Coordination Act

U.S. Fish & Wildlife Service

USFWS Fish and Wildlife Coordination Act Report and Corps responses to the recommendations are located in Exhibit C of Integrated Feasibility Report for Channel Improvements and Environmental Impact Statement (EIS)

Aug-1999 N/A N/A

46

Requirement Agency Compliance Document Date Issued Date Expires

Remaining Years (As of December

2016)

Endangered Species Act (ESA)

NOAA - National Marine Fisheries Service (NMFS)

Biological Opinion and Magnuson-Stevens Fishery Conservation and Management Act Essential Fish Habitat Response Columbia River Navigation Channel Operations and Maintenance No. 2011/02095

7/11/2012 N/A N/A

U.S. Fish & Wildlife Service

Biological Assessment Columbia River Channel Operations and Maintenance with letter of concurrence for “may affect but is not likely to adversely affect”

9/29/2010 N/A N/A

Biological Opinion Corps Nav Channel Dredging 2014 (Streaked Horned Lark) 6/6/2014 12/31/2018 2

Clean Water Act Section 401

State of Washington, Department of Ecology (DOE)

Water Quality Certification for Columbia River Operation and Maintenance Dredging between River Miles 3.0 to 145 and Amendments

2/19/2013; 8/14/2012; 4/29/2014; 7/15/2015

2/18/2018 1

State of Oregon, Department of Environmental Quality (DEQ)

Water Quality Certification for Columbia River Channel Improvement Project (CRCIP) and Columbia River Operations and Maintenance Dredging (O&M) and Amendment

5/19/2014; 9/3/2015 5/19/2024 7

Clean Water Act Section 404

Corps

Section 404(b)(1) Evaluation is Exhibit E of Columbia River Channel Improvement Project Final Supplemental Integrated Feasibility Report and Environmental Impact Statement

Jan-2003 N/A N/A

Coastal Zone Management Act

Corps

Coastal Zone Consistency Determination is Exhibit F of Columbia River Channel Improvement Project Final Supplemental Integrated Feasibility Report and Environmental Impact Statement

Jan-2003 N/A N/A

State of Washington, Department of Ecology (DOE)

Coastal Zone Management Consistency – Conditional Concurrence for Columbia River Channel Improvement Project

6/23/2003 N/A N/A

O&M Letter 4/18/2011 N/A N/A State of Oregon Department of Land Conservation and Development (DLCD)

Coastal Zone Management Decision for Deepening of Columbia River Federal Navigation Channel

6/23/2003 N/A N/A

O&M Letter 6/1/2007 N/A N/A

47

National Historic Preservation Act Section 106 Cultural Resources

Corps Corps Portland District Dredge Program Inadvertent Discovery Plan N/A N/A N/A

Oregon State Historic Preservation Office (SHPO)

Consultation Ongoing N/A N/A N/A

State of Washington Department of Archaeology & Historic Preservation

Consultation Ongoing N/A N/A N/A

National Pollutant Discharge Elimination System (NPDES)

Environmental Protection Agency (EPA)

Dredged Material is Exempt - 40 CFR 122.3(b) N/A N/A N/A

Migratory Bird Treaty Act Bald and Golden Eagle Protection Act

Corps Corps Portland District Dredge Program Migratory Bird Treaty Act and Bald and Golden Eagle Protection Act Guidance

N/A N/A N/A

Sediment Evaluation

Corps Lower Columbia River Federal Navigation Channel RM 3 to 106.5 Sediment Quality Evaluation Report

4/21/2017 Mar-2026 10

Portland Sediment Evaluation Team (PSET)

Portland Sediment Evaluation Team Level 2 dredged material suitability determination 7/5/2017 Mar-2026 10

InadditiontoCorpsProjectO&Mactivities,itisimportanttorecognizethattherearealsoNon‐FederalSponsoractivitiesconnectedtoProjectO&M.TheNon‐FederalSponsorsare“solelyresponsiblefortheoperationandmaintenance”ofdredgedmaterialplacementsitesspecificallylistedinArticleVIII,Subparagraph1.A.1ofthePCA.Inotherwords,theNon‐FederalSponsorsareresponsibleforpreparingthosesitestoreceivedredgedmaterialfromO&MoftheFNC(i.e.constructingcontainmentberms)andforsecuringallnecessarypermitsandapprovalsfortheiractivities.TheNon‐FederalSponsorshaveobtainedcompliancedocumentsfortheiractivitiesconnectedtoongoingProjectO&M.Currently,site‐specificpermitsareissuedtotheNon‐FederalSponsorsforshortdurationsandareroutinelyrenewedasneededtomaintaincompliance.

ExecutiveOrder13175,ConsultationandCoordinationwithIndianTribalGovernments

FederalagenciesshallestablishregularandmeaningfulconsultationandcollaborationwithtribalofficialsinthedevelopmentofFederalpoliciesthathavetribalimplications,andstrengthentheUnitedStatesgovernment‐to‐governmentrelationshipswithIndiantribes.Government‐to‐governmentcoordinationforculturalandnaturalresourceswasmost

48

recentlycoordinatedbytheCorpsvialettercorrespondence(3December2013)withtheConfederatedTribesandBandsoftheYakamaNation,theCowlitzIndianTribe,theConfederatedTribesofGrandRonde,theConfederatedTribesofSiletzIndiansofOregon,theConfederatedTribesoftheUmatillaIndianReservation,theNezPerceTribe,andtheConfederatedTribesoftheWarmSprings.Noresponseswerereceivedfromthetribes.

ConsistencyofExistingDocumentswithOngoingO&MActivities

TheexistingenvironmentalcompliancedocumentationiscompleteandconsistentwithcurrentO&Mdredginganddredgedmaterialplacementactivities.Newand/orextendedauthorizations,certificationsandclearancesareroutinelyobtainedbytheresponsiblepartypriortothestartofthedredgingseasonortheexpirationdateofexistingdocuments,whichevercomesfirst.BestmanagementpracticeshavebeenestablishedandtheenvironmentalconsequencesofongoingColumbiaRivernavigationchannelmaintenancedredginganddredgedmaterialplacementaregenerallywellunderstood.However,thereisnotenvironmentalcomplianceinplacetoallowforcontinuingmaintenanceofpiledikes.

Assessmentofneedsforthenext20yearsAsdiscussedabove,newsiteswillberequiredwithinthenext20yearstoprovidesufficientdredgedmaterialplacementcapacityforcontinuedchannelmaintenance.Structuralmeasurestoreducedredgingrequirementsorchangestomaintenancepracticesmayalsobeneededinordertomaintainareliablenavigationchanneloverthistimeperiod.Consultationswithresourceagencieswillberequiredandexistingenvironmentalcompliancedocumentationwillneedtobeupdatedaccordingly.TheColumbiaRiverisanaturallydynamicsystemandpreviousexperienceteachesusthatchannelmaintenancemustcontinuallyadapttochangingconditions.Ifactionsaretooprescriptive,frequentmodificationsarerequired,whichgreatlyincreasestheworkloadsofCorpsandresourceagencies.Instead,programmaticenvironmentalcoordinationwithintentionalflexibilityisstronglyrecommendedforthenextDMMPandpermitsassociatedwiththeproject.

TheremayalsobeopportunitiestoincreasebeneficialuseofdredgedmaterialforESA‐listedspeciessuchassalmonandstreakedhornedlarksthrucooperationwithresourceagencies.Also,analysistoidentifyadditionalshorelineplacementsitesisrecommendedbecauseoftheenvironmentalandchannelmaintenancebenefitsofshorelineplacement.Ideasrequiringfurtherevaluationinclude:placingdredgedmaterialtoreduceshipwakebeachstrandingofjuvenilesalmonathighrisksites,workingwiththestatesofOregonandWashingtontopromotethesaleofsandfromdredgedmaterialplacementsites,andcontinuingthepracticeofremovingdredgedmaterialtorenewsparsely‐vegetatedhabitatforstreakedhornedlarks.Addingnewplacementsitesandremovingmaterialfrom

49

placementsitesprovidesadditionalcapacityformaintenancedredging,andmaterialsalesgenerateroyaltiesfortheStatesofOregonandWashington.

TherelativedeclineinabundanceofPacificlamprey,anaquaticspeciesvaluedbyColumbiaRiverBasintribes,iscurrentlybeingstudied.TheeffectsofColumbiaRivernavigationchannelmaintenanceonlampreywillbeevaluated.TheCorpsisanactiveparticipantintheLampreyWorkingGroup,whichisamulti‐stakeholdergroupthatdevelopsbestmanagementpracticesforminimizingadverseimpactsonlampreyandistaskedwithdevelopingstrategiestosustainlampreypopulationsthroughouttheregion.

Fullenvironmentalcompliancemustbecompletedfortheactionofmaintainingpiledikes.

10 EconomicAssessment

EconomicBenefitsTheColumbiaRiverFNChasasteadyhistoryofprovidingregionalandnationaleconomicbenefits,whichincreaseovertime.In1907,morethan1.7milliontonsofcommoditieswereshippedon1,220ocean‐goingvesselsfromPortland,ORviatheColumbiaRiverwhichatthattimehadanauthorizednavigationchanneldepthof25ft.Thecargoesofthesevesselsincluded175millionftoflumberand18millionbushelsofwheat,flourincluded.Duringthisperiod,Portlandbecameanationalleaderasawheatandflourshippingport,leadingGalvestonandNewYorkatsometimes(Lyman,1909).In1962(channeldepth35ft),exportstotaledabout4.7milliontonsandimportswerenearly1milliontons.Grainsaccountedfornearlythree‐fourthsofallexports(WaterborneCommerceStatisticsfortheColumbiaandLowerWillametteRiverin1962).Afterchannelimprovementto40‐ftdepth,fromtheperiodof1987to1997,10to15milliontonsofwheatwasexportedannually,inadditionto5.5milliontonsofcorn(onaverage)andothercommoditiesincludingbarley,alumina,andcontainers(ColumbiaRiverChannelImprovementStudy–FinalIntegratedFeasibilityReport&EnvironmentalImpactStatement,1999).

In2014,the43ftdeepLowerColumbiaRiverFNCwasusedtotransportover61milliontonsofcargovaluedat$30billion,whichisanincreaseoverthe5‐yearaverage(2010thru2014)of56milliontonsworth$26billion.Vesselsdraftingthefullauthorizedchanneldepthof43ftcarriedapproximately13milliontonsofexportshipmentsworthnearly$5billionin2014.TonnageamountsrefertoCorpsWaterborneCommerceStatisticsCenter(WCSC)datafortheColumbia&LowerWillametteRiversbelowVancouver,WAandPortland,ORWaterwayasprocessedbytheCorpsChannelPortfolioTool(CPT).CargovaluesareestimatedbytheCPTbasedontheWCSCtonnageamountsmultipliedbynationalaveragecommodityunitprice($perton)dataderivedfromUSATradeOnline(https://usatrade.census.gov/).

50

TheColumbiaRiveristhenation'slargestwheatexportgatewayandthethirdlargestgrainexportcorridorintheworld(2014wheatexporttonnagebyproject,WCSCdatafortheColumbia&LowerWillametteRiversbelowVancouver,WAandPortland,ORWaterwayasprocessedbytheCorpsCPT;andOverviewofWheatMovementontheColumbiaRiverReportpreparedAugust17,2016basedonfiveyearaveragesdata(2011‐2015)byU.S.WheatAssociates;http://www.pnwa.net/wp‐content/uploads/PNWA_Handout.pdf).

TheColumbiaRiverFNC,asconstructedtochanneldepthof43ft,continuestoprovidesignificantregionalandnationaleconomicbenefits.Basedonrecentcapitalinvestmentsbychannelusers,thesebenefitsareexpectedtoremainstrongoverthenext20years.

MajorRecentandPlannedInvestmentsbychannelusers

AJune2015reportbythePortofPortlandandthePacificNorthwestWaterwaysAssociationentitled,“ImpactsofChannelDeepeningontheColumbiaRiver,”detailssomeofthemajorregionalinvestmentsthatweremadepossiblebythedeepeningoftheLowerColumbiaRiverFNCfrom40to43ft.Anexcerptfromthereportstates,“CompletionofthedeepeningoftheColumbiaRivershippingchannelin2010openedafloodgateofinvestmentsatterminalsandportsalongtheriver.Accordingtoaportrepresentative,thedeepeningandtheinvestmentsthatfollowedprovidesshippingandcommodityfirmswithcertainty—certaintythatports,terminalsandvesselscanmanagethemixofcommoditiesandtonnagethattoday’sglobaleconomyrequires.Firmshaveconfidencethatshipmentswon’tfacebacklogsatportsduetocapacityconstraints.Shipmentsmoveefficiently.Firmsalsospendlesstimemonitoring,planning,anddevelopingcontingencyshippingplans.”

Thereportgoesontodetailsomeofthoseinvestments:Table10‐1liststheinvestmentsinthestudyconductedbythePortofPortlandandPacificNorthwestWaterwaysAssociation.Itreferencesthefactthatprivateandpublicentitiesinvested$370millioninthePortlandHarbor,and$1billionatterminalsandportsalongtheColumbiaRiver,since2010.Thetablebelowdepictsinvestmentsplannedalongtheriveramountto$4.65billion.

Investmentscompletedtodateinclude:

▪ ThefirstnewgrainterminalbuiltintheU.S.in25years(atthePortofLongview)

▪ExpansionofthelargestexportgrainterminalontheWestCoastoftheU.S.

▪ ThefirstnewgrainbargeontheColumbiaRiversince2011

▪ Thelargestdry‐dockontheWestCoast(atVigor)

Maintainingtheshippingchannelto43ftwillhelpensurethecontinuedgrowthincargomovementandrelatedeconomicactivitythathasoccurredsincethedeepening.

51

Table10‐1:CurrentandPlannedPortInvestmentsalongtheColumbiaRiversince2010,ImpactsofChannelDeepeningontheColumbiaRiver,PortofPortlandandPacificNorthwestWaterwaysAssociation,2015.

Current and Planned Port Investments along the Columbia River since 2010

Current Investments Port  Project  Investment Amount  Description 

Longview  Export Grain Terminal (2012)  $230 million  New grain terminal 

Kalama  Temco LLC (2015)  $100 million  Increase capacity (grain) 

Kalama  Port of Kalama (2014‐15)  $7 million  Rail upgrades at Port 

Kalama  Kalama Export Grain (2011)  $36 million  Increase storage capacity 

Vancouver  United Grain Corp. (2012)  $80 million  Enlarge storage and 

handling capacity 

Vancouver  West Vancouver Freight Rail 

Access (2015) 

$228 million  Rail expansion, new loop 

track and road improvement 

Vancouver  Tidewater Barge Lines 

(2015) 

$30 million  Three new tugboats 

Portland  Columbia Grain (2015)  $44 million  Upgraded grain storage and 

handling 

Portland  Kinder Morgan Bulk 

Terminal (2013) 

$10 million  New ship loading facilities 

Portland  International Raw Materials 

(2014) 

$2 million  Improvements to rail and 

storage tanks 

Portland  LD Commodities (2014)  $21 million  Expanded grain storage and 

moving facilities 

Port  Project  Investment Amount  Description 

Portland  Vigor Industrial (2014)  $50 million  Largest drydock in the US 

Portland  Rivergate Road and Rail 

Improvements (2012) 

$82 million  Improve road and rail access 

and capacity 

Portland  Canpotex – Portland Bulk 

Terminal (2013) 

$140 million  Increase efficiency of 

shiploading 

Portland  Shaver Transportation 

(2014) 

$21 million  New barge, new tug and 

new engines 

Sub Total Current    $1.08 Billion  

52

Proposed Investments Longview  Millennium Bulk Terminal 

(2018) 

$600 million  New coal terminal 

Longview  Millennium Bulk Terminal 

(2018) 

$25 million  Smelter removal and 

environmental cleanup for 

new bulk terminal 

Kalama  NW Works (2017‐18)  $1.8 billion  New methanol plant 

St. Helens Port Westward  Global – Columbia Pacific Bio 

Refinery (2018) 

$80 million  Increased storage and rail 

improvements 

St. Helens Port Westward  NW Works (2017‐18)  $1.8 billion  New methanol plant 

St. Helens Port Westward  Ambre energy (2018)  $242 million  Coal transport 

Vancouver  Vancouver Energy (2018)  $100 million  Rail improvements and 

loading facilities 

Sub Total Proposed    $4.65 Billion

Total Current and Proposed since 2010  $5.73 Billion 

Vesselsloadedtofullauthorizeddepthuseentirenavigationchannelprojectarea

Theentirenavigationchannellength,fromRM3toRM105.5atthePortofVancouver,isutilizedbyvesselsloadedtothefullauthorizedchanneldepthof43ft.AsreferencedaboveinTable10‐1,thePortofVancouverhasthreecurrentprojectsandoneplannedprojectequatingtoatleast$438Mininvestments.Inparticular,the$80McapitalinvestmenttoenlargegrainstorageandhandlingintheUnitedGrainCorporationprojectdemonstratestheneedforcontinuedmaintenancefortheentiretyoftheprojectarea.InthePortofPortlandandPacificNorthwestWaterwaysAssociation’sreport(referencedabove),theUnitedGrainCorporationprojectisdetailedasfollows:“Withtheir$80millioninvestmenttoexpandtheirgrainterminal,UnitedGrainCorporationnowhasthelargestexportgrainterminalontheWestCoast,andthesecondtallestgrainstructureintheworld.Thedevelopmentstartedin2008‐2009,anticipatingthechanneldeepeningcompletionandlargershipswithdeeperdraftscallingonColumbiaRiverports.LikeothergrainterminalsalongtheColumbiaRiver,UnitedGrainCorporation’sexpansionincludedaddingstorageandtransportcapabilitiesforgrainsnewtothismarket—cornandsoybeans—alongwiththeirtraditionalwheatproduct.”TheinformationquotedabovecomesfrominterviewswiththeUnitedGrainCorporationandPortofVancouverinMarch2015(ImpactsofChannelDeepeningontheColumbiaRiver,PortofPortlandandPacificNorthwestWaterwaysAssociation,2015),andclearlysupportsthefactthattheproject’ssuccessisdependentonloadeddeepdraftvesselshavingaccesstotheupperreachesoftheLowerColumbiaRiverFNC.

53

In2015,thePortofVancouverexported5,540,913metrictonsofcargo,a3.9%increasefrom2014.Ofthatexportcargo,4.56millionmetrictonsconsistedofgrainproducts(wheat,soybeans,andcorn),a6.9%increasefrom2014.ThePortofVancouveralsoreportedarecordyearforimportsin2015at1,416,308millionmetrictons,a12.1%increasefrom2014(http://www.portvanusa.com/community/year‐in‐review/).Asmadeevidentbytheseinvestmentsandutilization,maintenanceofthefullextentofthe43‐footnavigationchanneliscrucialtotheeconomicstrengthoftheregionandnation.

MaintenanceCostsTheaverageannualcosttomaintaintheColumbiaRiverFNCforthepastfivefiscalyearsisaround$40million(seeTable10‐2).

Table10‐2:FederalFundsObligatedforColumbia&LowerWillametteRiversProject

FiscalYear FederalFundsObligated*

2012 $36.8million

2013 $37.5million

2014 $38.6million

2015 $47.0million

2016 $43.3million**

*doesnotincludecostsforGovernmentdredgemooringsfacilityclean‐upbecauseitwasnotcosttomaintainFNC**doesnotincludeC&LW$2.2millionGovernmentdredgeaccountpaymentbecauseitwasnotcosttomaintainFNC

ThecostsfromFY12toFY16areacombinationofdredgingandmaintenanceofexistingplacementsites.However,theannualcostisexpectedtoincreaseincomingyearstoaddressdeferredmaintenanceofpiledikestructuresusedtomaintaintheColumbiaRiverFNCaswellastheFederalcosttopreparenewplacementsites.Aroughorderofmagnitudeestimateforthisincreasedannualcostis$5to$10million.ThisestimateisbasedontheestimatedaveragecostperpiledikeforrepairstotheCottonwoodIslandpiledikesystem(over$1millioncalculatedfromthecostestimateintheMajorMaintenanceReportdated2017)andatotalneedforrepairstoover140piledikes(StructuralandHydraulicAnalysisofColumbiaRiverPileDikesReportdated2011).Thisestimateassumesthatrepairstomostpiledikeswillproceedaccordingtopriorityatanannuallevelofeffortthatisbelowthebudgetarythresholdformajormaintenanceactions(mostrecently$6.2millionasdefinedinEngineeringCircular11‐2‐214dated31March2017),sothismaintenancecostwillcontinueforatleastthenext20years.Thisalsoassumesthatmostifnotallpiledikesystemsintheprojectareawillneedtobereplacedorrepairedinordertomaintainfunctionundercurrentconditions.Therefore,forcomparisonwiththeeconomicbenefitsdetailedabove,thetotalannualcosttomaintaintheColumbiaRiverFNCisaround$50M.

54

DeterminationthatContinuedMaintenanceisWarranted

AnalysisoftheeconomicbenefitandcostindicatorsshowsthatcontinuingO&MoftheColumbiaRiverFNCbetweenRM3and105.5iswarranted.Annualeconomicbenefitsconclusivelyoutweighannualprojectmaintenancecosts.Additionaleconomicanalysisisnotnecessary.

11 FindingsThepreliminaryassessmentofeconomicbenefitsandcostsprovesthatcontinuedmaintenanceoftheLowerColumbiaRiverFNCiswarranted;however,adredgedmaterialmanagementstudyandDMMPisneededtoaddresskeyprojectinformationgapsandchallenges.

Themostcriticalconsiderationisthedredgeequipmentavailabletotheproject.Existingdredgeequipmentavailabilityisuncertain,especiallythelimitednationalhopperdredgingfleetofGovernmentandcontracthopperdredges,andadditionaloralternativedredgingequipmentshouldbeconsidered.SandwavesareachronicshoalingproblemfortheColumbiaRiver;however,sandwavedredgingisinefficientfortheexistingdredgeequipmentandalternativetechniquesforaddressingsandwaveshoalingshouldbefurtherinvestigated.TheteamwillneedtodetermineifitiswithinscopetoevaluatealternativedredgeequipmentaspartoftheDMMP.Also,thehopperdredgingfleetisagingandtherewilllikelybechangesduringthe20‐yearperiod.TheplanmustthereforeoptimizeandinformthecurrentandfuturedredgingfleetavailableforLowerColumbiaRiverFNCO&M.

Forthepurposesofthisassessment,theforecastedaverageannualdredgingneedforthenext20yearsisexpectedtobe6.5mcy(130mcytotal).However,thisvolumedependsonmanychannelO&Mvariablesthataffectshoaling,suchasrivertrainingstructures.Aninventory,condition,andplanforexistingrivertrainingstructuresneedstobedeveloped.

Differentplacementmethodsalsoaffectfutureshoaling.Thesustainablerateofuplandandin‐waterplacementneedstobedeterminedtosupportregionalsedimentmanagement.

Thirteenofthenineteenexistinguplandplacementsitesarealreadyfullorhavecapacityforjustoneortwomoreplacementevents.Manyoftheselimitedcapacitysitescouldbefullwithinthenextfiveyears.AmajorityoftheuplandplacementsitesreachingcapacityarelocatedbetweenRMs34and86.5,whichwillresultincriticalchannelmaintenancechallengesincludingsignificantcostincreasestoplacedredgedmaterialinotherlocations,unlessnewalternativesareidentified.Overthenext20yearperiod,theprojectedneedforuplandplacementisupto40mcyandtheremainingcapacityafter2016isjust16.75mcy,adifferenceof23.25mcyadditionalcapacityneeded.

55

Althoughthecapacityforin‐waterplacementinthisdynamicrivercannotbereasonablyquantified,therearestrongindicationsthatcapacityisbecomingincreasinglylimited.Thoseindicationsinclude:stablein‐waterplacementlocations,whichareusedfor70%ofdredgedmaterialplacement,arebecomingdepth‐limitedbecauseofdredgedmaterialaccumulationandsomepastsitesappeartobecausingshoalinginthechannelwhichmakesthemunsuitableforfutureplacement.Improvementofin‐waterplacementtechniquesusinghydraulicanalysisisessentialtoproperlyaccommodatethe80‐100mcyofdredgedmaterialthatisprojectedtobeplacedin‐waterthroughoutthe20yeardurationofthisplan.Anotheroptionistheincreaseduseoftemporaryin‐waterdredgedmaterialrehandlesites(sumps).Table11‐1providesestimatedvolumesfordifferentdredgedmaterialplacementmethodsforthenext20yearsofchannelO&M.Forthepurposesofthisassessment,theestimateassumestheplacementmethodallocationisconsistentwithcurrentpractices.

Table11‐1:EstimatedDredgedMaterialPlacementVolumeforNext20Years

PlacementMethod EstimatedVolume(CY)

Upland 20to40mcy

Shoreline 10to20mcy

In‐Water(River) 80to100mcy

Ocean Unknownifneeded

Lastly,thereareenvironmentalcomplianceandrealestateneeds.AlthoughtheexistingenvironmentalcompliancedocumentationiscompleteandconsistentwithcurrentO&Mactivitiesfordredginganddredgedmaterialplacement,additionalcomplianceisneededforpiledikemaintenance.Therealestaterightsforexistingplacementsiteswillexpirebeforetheendofthenext20yearchannelO&Mperiod.

57

13 References

AECOMforPortlandDistrict,U.S.ArmyCorpsofEngineers.2011.StructuralandHydraulicAnalysisoftheColumbiaRiverPileDikes.

AdamJ.HeinemanandJudithRichardson.1968.SoThatShipsMayPass:Historical,Structural,andOperationalDevelopmentofNavigation–LowerColumbiaandWillametteRivers.

BeasleyT.M.;Jennings,C.D.;andD.A.McCullough;1986.SedimentAccumulationRatesintheLowerColumbiaRiver;J.Environ.Radioactivity,103‐‐123.

DavidA.Jay,ProfessorPh.D.inPhysicalOceanography,PortlandStateUniversity,March2013.TheTrajectoryoftheLowerColumbiaRiverandEstuary,1850‐2013.

Eriksen,Karl.W,PortlandDistrict,U.S.ArmyCorpsofEngineers,Portland,Oregon.1989.ColumbiaRiverShoalingAnalysis.

Haushild,W.L.;Perkins,R.W.;Stevens,H.H.;DempsterG.R.;Glenn,J.L.1966.RadionuclidetransportinthePascotoVancouver,WashingtonreachoftheColumbiaRiverJuly1962toSeptember1963.

Headquarters,U.S.ArmyCorpsofEngineers,Washington,D.C.2014.U.S.ArmyCorpsofEngineersAnnualReport.

Hickson,RobertE.1961.ColumbiaRiverShipChannelImprovementandMaintenance.

Hubbell,D.W.;GlennJ.L.;Stevens,H.H.Jr.1971.StudiesofsedimenttransportintheColumbiaRiverEstuary.Proceedings1971TechnicalConferenceonEstuaries,ofthePacificNorthwest.Proc.Circ.42,Eng.ExperimentStation.Corvallis:OregonStateUniversity.

58

Karlin.R.;1980.SedimentsourcesandclaymineraldistributionsofftheOregoncoast.J.Sed.Pet.,543‐60.

Levin,DouglasR.,W.JeffLillycrop,andAlexander,MichaelP.WaterwaysExperimentStation,U.S.ArmyCorpsofEngineers.September1992.TechnicalReportHL‐90‐17SandWaves:Report1SandWaveShoalinginNavigationChannels.

Lyman,WilliamD.1909.TheColumbiaRiver:ItsHistory,ItsMyths,ItsScenery,ItsCommerce.

PortofPortland.November1991.GuidetoNavigationontheLowerColumbia.

PortofPortland.2011.ColumbiaRiverReflections.AMemoirbyOgdenBeeman.

PortofPortlandandPacificNorthwestWaterwaysAssociation.June2015.ImpactsofChannelDeepeningontheColumbiaRiver.

PortlandDistrict,U.S.ArmyCorpsofEngineers,Portland,Oregon.June1998.ColumbiaandLowerWillametteRiverFederalNavigationChannel,FinalIntegratedDredgedMaterialManagementPlanandSupplementalEnvironmentalImpactStatement.

PortlandDistrict,U.S.ArmyCorpsofEngineers,Portland,Oregon.August1999.IntegratedFeasibilityReportforChannelImprovementsandEnvironmentalImpactStatement,Columbia&LowerWillametteRiverFederalNavigationChannel.

PortlandDistrict,U.S.ArmyCorpsofEngineers,Portland,Oregon.January2003.TheColumbiaRiverChannelImprovementStudy–FinalSupplementalIntegratedFeasibilityReport&EnvironmentalImpactStatement.

PortlandDistrict,U.S.ArmyCorpsofEngineers,Portland,Oregon.30September2013.ColumbiaRiverFederalNavigationChannelInterimOperations&Maintenance(O&M)Plan.

59

PortlandDistrict,U.S.ArmyCorpsofEngineers,Portland,Oregon.1986‐2016.USACEDredgingandPlacementRecords.

Roy,E.H.;Creager,J.S.;Walter,S.R.;Borgeld,J.C.1979.AninvestigationtodeterminethebedloadandsuspendedsedimenttransportovertheoutertidaldeltaandmonitorthesedimentaryenvironmentofsitesEandDnearthemouthoftheColumbiaRiver.

Sherwood,C.R.,J.S.Creacher,E.H.Roy,G.GelfenbaumandT.Dempsey;1984.SedimentaryprocessesandenvironmentsintheColumbiaRiverEstuary.ColumbiaRiverEstuaryDataDevelopmentProgram,ColumbiaRiverEstuaryStudyTaskforce,Astoria,Oregon317pp.

Simenstad,C.A.,D.A.Jay,C.D.McIntyre,C.Sherwood,andL.Small,1984.ThedynamicsoftheColumbiaRiverEstuaryecosystem,CREST,Astoria,Oregon,695pp.,twovolumes.

U.S.ArmyCorpsofEngineers,U.S.EnvironmentalProtectionAgency,WashingtonDepartmentofEcology,WashingtonDepartmentofNaturalResources,OregonDepartmentofEnvironmentalQuality,IdahoDepartmentofEnvironmentalQuality,NationalMarineFisheriesService,andU.S.FishandWildlifeService.2016.SedimentEvaluationFrameworkforthePacificNorthwest.PublishedJuly2016,bytheU.S.ArmyCorpsofEngineers,NorthwesternDivision,172pp+Appendices.

Whetten,J.T.;Kelley,J.C.;Hanson,L.G.;1969.CharacteristicsofColumbiaRiversedimentandsedimenttransport.J.Sed.Pet.39:1149‐1166.