Design Bridges Culverts Wildlife Passage 122710

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Design of Bridges and Culverts for

Wildlife Passage at Freshwater Streams

December2010


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ACKNOWLEDGEMENTS

TheDesignofBridgesandCulvertsforWildlifePassageatFreshwaterStreamshasbeencompiledthroughacollaborativeeffortbetweentheEnvironmental,Bridge,Construction,andHydraulicsSectionsoftheMassachusettsDepartmentofTransportationHighwayDivision.MassDOTpersonnelwhohavecontributedtothisdocumentinclude:

LennyAversa ThomasMcGuireHenryBarbaro TimMeyerAlexBardow RichardMurphyRobertBoone AmerRazaWilliamClougherty LarrySalvatoreTimDexter AnnSullivanJessicaKenny VickiVolzBrettLoosian

Thefollowingenvironmentalandregulatoryrepresentativeshaveprovidedtechnicaladviceduringthecreationofthisdocument.

KarenK.Adams,UnitedStatesArmyCorpsofEngineersCarrieBanks,DivisionofEcologicalRestoration,MassDept.FishandGameChristopherBoelke,NationalMarineFisheriesServiceAlisonBowden,TheNatureConservancyScottJackson,UniversityofMassachusettsAmherstGeorgeannKeer,DivisionofEcologicalRestoration,MassDept.FishandGameGregPenta,UnitedStatesArmyCorpsofEngineersTimPurinton,DivisionofEcologicalRestoration,MassDept.FishandGameEdwardReiner,UnitedStatesEnvironmentalProtectionAgencyJohnSargent,UnitedStatesArmyCorpsofEngineers

DavidNyman,P.E.ofComprehensiveEnvironmentalInc.hasprovidedtechnicaladviceandhasplayedakeyroleincompilingthisdocument.


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Contents

1.0 Introduction................................................................................................................................. 12.0 The Massachusetts River and Stream Crossing Standards ................................................. 7

2.1 RationaleforDesigningStreamCrossingsforHabitatContinuity.................................................... 72.2 EvaluatingExistingCrossingsRelativetoWildlifePassage.............................................................. 122.3 Introduction to the Massachusetts River and Stream Crossing Standards ....................................152.4 DeterminingtheBankfullWidthofaRiverorStream.....................................................................202.5 DeterminingOpenness.................................................................................................................. 242.6 ThresholdsforOptimumStandards ................................................................................................. 252.7 RegulatoryContext........................................................................................................................... 27

2.7.1 USArmyCorpsofEngineersMassachusettsGeneralPermit............................................282.7.2 USArmyCorpsofEngineersComprehensivePermitforBridges.....................................322.7.3 Massachusetts401WaterQualityCertificationRegulations ............................................ 33

3.0 Criteria for Wildli fe Passage at Bridges and Culverts ......................................................... 373.1 CriteriaforMaintenanceActivities.................................................................................................. 383.2 CriteriaforReplacementsofExistingStreamCrossingsthatAreNotConsideredMaintenance

Activities............................................................................................................................................413.3 CriteriaforStructuresatNewStreamCrossings............................................................................. 453.4 Exceptions.........................................................................................................................................463.5 ConstraintsAnalysis ..........................................................................................................................473.6 Order of Preference of Alternatives................................................................................................. 48

4.0 Design Approaches for Wildlife Passage at Stream Crossings ......................................... 514.1 Range of Ecological Solutions ........................................................................................................... 514.2 SummaryDescriptionsofDesignApproaches .................................................................................53

4.2.1 ValleySpan.......................................................................................................................... 564.2.2 StreamSpan........................................................................................................................ 594.2.3 Stream Simulation ...............................................................................................................624.2.4 NoSlopeCulvert................................................................................................................. 674.2.5 BridgeReplacementwithRetainedAbutments.................................................................70

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4.2.6 FullSpanEmbeddedMultipleBoxCulvert.........................................................................744.2.7 RoughenedChannelEmbeddedCulvert............................................................................ 784.2.8 SimpleEmbeddedCulvert................................................................................................... 824.2.9 FishPassageHydraulicDesign............................................................................................ 854.2.10 FlowConveyanceDesign.................................................................................................... 89

4.3 SupplementalMeasures ...................................................................................................................915.0 Constraints on Providing Passable Stream Crossings ....................................................... 93

5.1 GeneralDiscussionofDesignConstraints........................................................................................935.2 Typical Considerations and Constraints at Stream Crossing Structures ......................................... 945.3 ConstraintsAffectingReplacementofExistingCrossingStructures ...............................................97

6.0 Project Development and Design for Stream Crossings .................................................. 1076.1 MassDOT Project Development and Design Guide .......................................................................1076.2 MassDOTBridgeManual ................................................................................................................1076.3 Design Development Requirements and Stream Continuity ........................................................1096.4 Priorities of the Design Technique Options ...................................................................................112

References: ................................................................................................................................... 115

List of Tables

Table21. PassageClassificationforExistingStreamCrossingStructures......................................................13

Table23. EquationsforEstimatingBankfullChannelGeometryandDischarge forStreamsintheTable24. EligibilityRequirementsforMassDOTStreamCrossingStructuresunderACOEComprehensive

Table51. DesigningBridgesandCulvertstoMeettheMassachusettsRiverandStreamCrossingTable61. ProjectDevelopmentandDesignGuideProvisionsforHabitatContinuityatStreamCrossings108

Table22. SummaryoftheMassachusettsRiverandStreamCrossingStandards........................................17NortheasternUnitedStates(Source:Bent,2006).................................................................... 23PermitforBridgesandMAGeneralPermitCategories1and2............................................... 35

Table31. OrderofPreferenceforAlternativeDesignMeasuresforMaximizingWildlifePassage.............49Table

4

1.

StreamCrossing

Design

Approaches...............................................................................................

53

Table42. SupplementalMeasuresatStreamCrossings................................................................................ 91

Standards:PotentialDesignConstraints ................................................................................... 95

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List of Figures

Figure21. PerchedCulvertsFragmentAquaticHabitat..............................................................................10Figure22. ConditionsAffectingWildlifePassageatCulverts .........................................................................11Figure23. StreamSimulationCulvertDesign................................................................................................. 16Figure24. BankfullChannelWidth.................................................................................................................. 21Figure25. Openness for Culverts and Bridges ................................................................................................ 24Figure31. MassDOTProjectWildlifeAccommodationScenariosforNewandReplacementStream

Crossings.....................................................................................................................................42Figure41. The Range of Ecological Design Solutions at Stream Crossings ....................................................52Figure42. Range of Stream Crossing Design Approaches (Adapted from Gubernick, 2003). ...................... 55Figure43. ValleySpan......................................................................................................................................57Figure44. StreamSpan.................................................................................................................................... 60Figure45. StreamSimulation.......................................................................................................................... 64Figure46. NoSlopeCulvert............................................................................................................................. 68Figure47. Bridge Replacement with Retained Abutments ............................................................................ 72Figure48. FullSpanEmbeddedMultipleBoxCulvert .................................................................................... 76Figure49. RoughenedChannelEmbeddedCulvert........................................................................................80Figure410. SimpleEmbeddedCulvert ............................................................................................................83Figure411. FishPassageHydraulicDesign...................................................................................................... 87Figure51. ExampleofVerticalClearanceLimitationsforaReplacementStructure.....................................97Figure52. ExampleofWetlandImpactsofRaisingApproachRoadtoReconstructedStreamCrossing.....98Figure53. PotentialAlterationofUpstreamWetlandsasaResultofCulvertReplacement......................100Figure54. ExampleofMeasuretoPreventHeadcutting.............................................................................101Figure55. PotentialAlterationofFloodElevationsasaResultCulvertReplacement................................102Figure56. Utilities at Existing Crossings Can Limit Options for Replacement Structures. ..........................104

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Appendices

AppendixA.MassachusettsRiverandStreamCrossingStandardsAppendixB.MassDOTStreamCrossingStructuresRatingChartandRelatedInformationAppendixC.USArmyCorpsofEngineersMassachusettsGeneralPermitAppendixD.USArmyCorpsofEngineersMassachusettsDepartmentofTransportationComprehensive

PermitforBridgesAppendixE.Massachusetts401WaterQualityRegulations

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DesignofBridgesandCulvertsforWildlifePassageatFreshwaterStreams

1.0 Introduction

TheMassachusettsDepartmentofTransportationHighwayDivision(MassDOT)hasjurisdictionovernumerousroadwaystreamcrossings. Existingbridgesandculverts,aswellasfuturestructures,potentiallyaffectaquaticandterrestrialwildlifemovementalongtheCommonwealthsstreamsandripariancorridors,whichinturnpotentiallyaffectstheviabilityofwildlifepopulationsandecologicalsystems.MassDOTconsidersitimportanttodesignnewandreplacementstreamcrossingstoaccommodatefishandotherwildlifepassageandpreventadverseimpactstoimportantecologicalsystems. Therefore,MassDOThasdevelopedthisguidancedocumenttoaddresswildlifepassageissuesatnewandreplacementbridgesandculvertsandtocomplywithregulatorystandardsforstreamcrossings.InMassachusetts,stateandfederalregulationsofstreamcrossingsapplyrequirementsbasedontheMassachusettsRiverandStreamCrossingStandards.1 Chapter2ofthisdocumentdiscussestheseStandardsindetail,alongwiththeregulatorycontextinwhichthestandardsareapplied. TheremainderofthedocumentpresentsMassDOTguidanceonaddressingtheregulationsandStandards. MassDOTanticipatesthatprojectplannersanddesignerswillusethisguidanceinconjunctionwithotherstandardMassDOTtechnicalreferencestoevaluate,select,anddesignstreamcrossingsforconveyancecapacity,structuralintegrity,andwildlifehabitatcontinuity.Thisdocumentfocusesonfishandotherwildlifepassageatnewandreplacementbridgesandculvertsatfreshwaterstreams. Attidalstreamcrossings,wildlifehabitatcontinuityandfishpassageconsiderationsdifferfromfreshwater,nontidalsystems. Applicationofwildlifeaccommodationmeasuresappropriateforfreshwatersystemsmaybeecologicallyunjustifiedfortidalsystems. Thisdocumentdoesnotaddresstidalsystems. Asthisdocumentfocusesonwildlifepassage,italsodoesnotspecificallyaddressotherpotentialhabitatimpactsassociatedwithplacingstructuresinoroverstreams,suchaspermanentimpactsonbenthicresources,impactsresultingfromshade,andstormwatermanagementimpacts. ProjectplannersanddesignersshouldconsultMassDOTenvironmentalprofessionalsandotherMassDOTreferencematerialsfordirectionabouttheseissues.MassDOThasdevelopedthisdocumentinlightoftheoverallguidingprinciplesprovidedbytheDepartmentsProjectDevelopmentandDesignGuide(2006). Theintroductionofthatprincipleguidancedocumentforthedesignandimplementationoftransportationprojectsstates:

TransportationandqualityoflifeinourCommonwealthcommunitiesareinextricablylinked.Thisconnectionislargelyinfluencedbytherolethathighways,streets,andsidewalksplayinourlives.ExcellenttransportationiscriticaltoahealthyandvibrantCommonwealthMassDOT[formerlyMassHighway],initsroleasstewardforourroadways,mustconsiderabroadrangeoffactorsinmaintainingandimprovingthissystem,including:

Safetyforallusers

1MassachusettsRiverandStreamContinuityPartnership,2006. AppendixAincludesacopyofthecurrentstandards.

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Functionalitytheneedforaccessandmobility Accessibilityforpeoplewithdisabilitiesasaprerequisitetoaccesstoemployment,

recreation,andhealthcare Mutualsupportandcompatibilitybetweentransportationfacilitiesandservicesandthe

adjacentlandusesandassociatedactivitiestheyserve Consistencywithtransportationplansandpolicies,andenvironmentalregulations,that

guidethecommunity,theregion,thestate,andtheFederalgovernment Transportationfacilitydesignandoperationalrequirementsestablishedbyothers Inputandparticipationfromlocalconstituents,andtheappropriatelocal,regionaland

statereviewingagencies CosteffectivenessthevaluereturnedtotheCommonwealthfortheinvestmentsmadeintransportation

TheCommonwealthofMassachusettsiscommittedtocaringforthebuiltandnaturalenvironmentsbypromotingsustainabledevelopmentpracticesthatminimizenegativeimpactsonnaturalresources,historic,scenicandothercommunityvalues,whilealsorecognizingthattransportationimprovementshavesignificantpotentialtocontributetolocal,regional,andstatewidequalityoflifeandeconomicdevelopmentobjectivesWelldesignedtransportationinfrastructurethatisresponsivetoitscontextistheproductofthoughtfulplanning.Bybringingtogethertransportationprofessionals,localresidents,andinterestgroups,transportationplanningcanproducepublicfacilitiesandprogramsthatsupportcommunitygoals,providesafeandefficienttransportationforindividualsandgoods,enhancetheeconomy,andprotectthenaturalenvironment.Thepurposeof[the]ProjectDevelopment&DesignGuide(Guidebook)istoprovidedesignersanddecisionmakerswithaframeworkforincorporatingcontextsensitivedesignandmultimodalelementsintotransportationimprovementprojects.Theemphasisistoensurethatinvestmentsintransportationinfrastructureencourageprojectsthataresensitivetothelocalcontextwhilemeetingtheimportantneedsofthepeopletheyserve.

InkeepingwiththeoveralldirectionestablishedbytheGuidebook,thechaptersofthisguidancedocumentprovidethefollowing:

1. Introduction.2. TheMassachusettsRiverandStreamCrossingStandards.

Thischapterpresentsanoverviewoftherationaleforintegratingwildlifepassageelementsintothedesignofbridgesandculverts,describesamethodforassessingthedegreeofwildlifepassage

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affordedbyastructure,andsummarizesthekeyelementsoftheMassachusettsRiverandStreamCrossingStandards.2Thischapteralsodescribestheregulatoryframeworkfordevelopingstreamcrossingstructuresthatprovidehabitatconnectivity. ThisincludesadiscussionoftheUSArmyCorpsofEngineersMassachusettsGeneralPermit,andtheComprehensivePermitforBridgesissuedforqualifyingMassDOTprojects. ThechapteralsodiscussestheapplicabilityoftheMassachusetts401WaterQualityCertificationregulationsandtheWetlandsProtectionActRegulations.

3. CriteriaforWildlifePassageatBridgesandCulverts.MassDOTactivitiesinclude:

Themaintenanceofroadwayinfrastructure,toprovideforthecontinuingsafetyandserviceabilityofexistingroadways;

Reconstructionandreplacementofroadwaysandroadwaystructures(suchasbridgesandculvertsatstreamcrossings)toimproveandupgradeexistingroadwaystomeetevolvingtransportationneedsandsafetystandards;

ConstructionofnewroadwaystomeetthetransportationneedsoftheCommonwealthofMassachusetts.

Foreachofthesebroadcategoriesofactivities,therearedifferingopportunitiesandconstraintsfortheprovisionoffishandotherwildlifepassage. Chapter3describesMassDOTscriteriaforconsideringtheneedsforwildlifepassageformaintenanceactivitiesinvolvingculvertandbridgerepair;projectsforimprovement/reconstructionofexistingroadways,culverts,andbridges;andprojectsinvolvingtheplanning,selection,anddesignofnewstreamcrossingstructures.Subsequentchaptersthendiscussindetailthedesignmethodologiesandpertinentconstraintsforthesecriteria.

4. DesignApproachesforWildlifePassageatStreamCrossings.Chapter4describesthegeneralrangeofdesignapproachesforconveyanceofflowsatstreamcrossings,whileaccommodatingthepassageoffishandotherwildlife. Thedocumentbrieflydescribesseveralspecificdesignmethodstoachievevaryingdegreesofwildlifepassage. Thesedescriptionsincludesuggestedreferencematerialsthatthedesignershouldconsultfordetailedproceduresfortheanalysisanddesignofbridgesandculvertstomeetwildlifepassageobjectives.Thisguidancedocumentdoesnotpresentdetaileddesigndata,butrathercitespotentialtechnicalresourcesthatdesignersandreviewerscanconsult.

2TheRiverandStreamContinuityPartnership,whichincludestheUniversityofMassachusettsAmherst,MassachusettsDepartmentofFishandGameRiverwaysProgram,andTheNatureConservancy,developedtheMassachusettsRiverandStreamCrossingStandards.

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5. ConstraintsonProvidingPassableStreamCrossings.Thischapteridentifiescommondesignconstraintsthatapplytothedevelopmentofbridgeandculvertdesigns. Theseconstraintscanapplytonewandreplacementcrossings,butareparticularlychallengingatreplacementstructures,wherepastdecisionscanlimitcurrentopportunitiesbecauseofconcernsregardinghydrauliccapacity,floodcontrol,rightofwaylimitations,structuralintegrity,otherregulatoryrequirements,andconstructionfeasibility. Thedesignerneedstoidentifyandcharacterizesuchconstraintsearlyinthedesignofbridgeandculvertimprovementprojects. DefinitionoftheconstraintswillenablecollectionofpertinentinformationforchoosingastructurethatwouldmaximizecompliancewiththeRiverandStreamCrossingStandards,whileaddressingothercriticaldesignparametersandbalancinghabitatcontinuityobjectivesagainstotherregulatoryrequirements.

6. ProjectDevelopmentandDesignforStreamCrossings.ThischapterdescribeshowMassDOTsprojectdevelopmentanddesignprocessintegratesprovisionsforcomplyingwiththeMassachusettsRiverandStreamCrossingStandards. TheMassachusettsHighwayProjectDevelopmentandDesignGuide(2006)andtheBridgeDesignManualincludekeyprovisionsthatensurethattheprojectinitiation,planning,development,anddesignprocessconsidershabitatcontinuityatstreamcrossings,providesforcoordinationwithaffectedenvironmentalagencies,andincorporatescrossingdesignmeasurestoachievecompliancewithapplicableregulations.

TheMassDOThandbookDesignofBridgesandCulvertsforWildlifePassageatFreshwaterStreamsisnotastandalonedocument. Thedesignofstreamcrossingswithadequateflowcapacity,structuralintegrity,andwildlifehabitatcontinuitywillrequirethedesignertousethisguidanceinconjunctionwiththefollowingdocumentsandothertechnicalreferencesonthedesignofhighwaystructures:

TheMassDOT(formerlyMassHighway)ProjectDevelopmentandDesignGuide(2006),inparticularthefollowingchapters:

oChapter2ProjectDevelopment;oChapter8 DrainageandErosionControl;oChapter10Bridges;oChapter14 WildlifeAccommodation.

TheMassDOTBridgeManual(2007),3andinparticular,thefollowingchapter:oChapter2 PreliminaryEngineeringGuidelines.

3AtthetimeofpublicationofthisHandbook,MassDOTisintheprocessofdevelopingtheLRFDBridgeManual. ThishandbookisintendedtobeconsistentwithMassDOTbridgedesignpractice;designersshouldconsultthemostcurrentdesignpracticesadoptedbyMassDOTinconjunctionwiththeuseofthisguidanceonwildlifeaccommodation.

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MassachusettsRiverandStreamCrossingStandards(March1,2006,includedasAppendixAofthisdocument),andfutureupdatesoftheseStandards,asapplicable.

TheMassDOTStreamCrossingStructuresRatingChart,andtherelatedRiver/StreamContinuityProjectresourcematerials(includedasAppendixBofthisdocument)forevaluatingexistingcrossingsrelativetotheirwildlifepassagecharacteristics,including:

oMassDOTStreamCrossingStructuresRatingChart(andfutureupdates,asapplicable);oStreamContinuityPartnershipRoadStreamCrossingInventory(FieldDataForm);o InstructionGuideforFieldDataSheet:RoadStreamCrossingInventory.

Applicableregulationsgoverningstreamcrossings,including:oUSACEMassachusettsGeneralPermit(MGP),includedasAppendixC;oUSACEMassDOTComprehensivePermitforBridges(CPB),includedasAppendixD;oMassachusetts401WaterQualityCertificationRegulations(AppendixE);andoOtherregulationsasapplicable.

Othertechnicaldesignreferencescitedinthisdocument,containingdetailedevaluationanddesignmethodologiesforachievingwildlifepassageatculvertsandbridges.

ImportantNoteonTerminologyUsedinthisHandbookMassDOTterminologyforbridgesasusedinvariousDepartmentreferencematerialsencompassesawidevarietyofstructures,includingbothclearspantypestructuresandsomeculverttypestructures.* Forthepurposesofthishandbook,thefollowingconventionforterminologywillbefollowed:Bridge: Astructurethatsupportsaroadwayorotheraccesswayoverawaterbodybymeansofaspan. This

typeofstructuredoesnothaveaconstructedstructuralinvert(bottom)andthereforedoesnotfullyenclosethechannelthatitspans. Itmayconsistofadecksupportedonabutmentsorpiers,openbottomboxorhalfpipe,orotherstructuralarch.

Culvert:Astructurethatsupportsaroadwayorotheraccesswayoverawaterbodybymeansofafullyenclosedconduit(completepipeorbox)thatalwayshasaconstructedbottomanddoesnottypicallyhaveabutmentsorpiers.Commonculverttypesincludecircular(round)pipe,ellipticalpipe,pipearch(asquashedroundpipecrosssection),andsquareorrectangularbox. Culvertsmayormaynotbeembedded(aninstallationwherestreambedmaterialisplacedorallowedtoaccumulateinthebottomoftheconduit).

*Forexample,MassDOTmayassignaculvertaBridgeNumberandconsideritabridgeundercertainjurisdictionalcontexts.

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2.0 The Massachusetts River and Stream Crossing Standards

Thischapterdiscussestheunderlyingreasonsfordesigningstreamcrossingstoprovideforunobstructedwildlifepassage,orhabitatcontinuity. Thechapterexplainshowconditionsatculvertsandbridgescancreatebarrierstoaquaticandotherwildlifepassage,andpresentsamethodforassessingexistingstructuresrelativetothedegreetheyallowforwildlifepassage. ThechapterthenintroducestheMassachusettsRiverandStreamCrossingStandards. Italsosummarizestheregulatoryframeworkgoverningthedesignofbridgesandculvertstoprovideforhabitatcontinuity.2.1 Rationale for Designing Stream Crossings for Habitat Continui ty

Continuous,unobstructedstreamsystemsarecriticaltomaintaininghealthy,viableecosystems. Streamcontinuity isalsoessentialtothesurvivalof individualsandsubpopulationsofwildlifespeciesthatusestreamandriparianhabitat.Newandexistingbridgesandculvertscaninterruptthecontinuityofstreamsystems,imposingstructural,hydraulic,andbehavioralbarrierstothemovementoffishandotherwildlife. Historically,streamcrossingstructures have been designed to address traffic considerations, structural integrity, and hydrauliccapacity. Crossingstructurescanalsobedesignedtoaddresstheunobstructedmovementofwildlife. Therationaleforprovidingwildlifepassageisdiscussedbelow.Considerthefollowingcomparisonoftransportationsystemsandstreamsystems:

GroundtransportationsystemsHighways, roads, railroads, bicycle paths, and pedestrian ways are linear systems. They areindispensabletothemovementofpeopleandmaterialsacrossthelandscape. Ifaroadwaynetworkis interruptedbyanobstruction, thenpointsoforiginanddestinationalongthe roadwaybecomeisolatedfromeachother.Ifaroadwayisconstructedalonganalignmentthatmeetsariverorstream,thenasuitablecrossingisrequiredtoprovidecontinuityoftheroadwayacrossthestream. Ifthecrossingisabridge,thentoprovideadequateandcontinuousaccess,thebridgemusthaveawidth,slope,andsurfacetreatmentthatprovidesforthefreeflowoftrafficacrossthestructure.Bridgesaredesigned tobe continuous inhorizontal and vertical alignmentwith the approachingroadway, and to accommodate the vehicle types, sizes, speeds, and traffic volumes using theapproachingroadways. Bridgesnotmeetingallthesecriteriawouldrestrictorobstructtheflowoftrafficpotentiallyisolatingpointsoforiginanddestinationfromeachother.StreamsystemsRivers,brooks,andstreamsarelinearecosystems. Streamchannelsandadjacentripariancorridorsarecriticaltothemovementofaquaticandterrestrialwildlifeacrossthe landscape,togetherwithmaterials(largeandsmallwoodydebris,organicdetritus,andnutrients)thataffecttheirhabitat. Ifa

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stream is interruptedbyanobstruction,thenessentialecological infrastructure isunderminedandhabitats along the corridor become isolated from each other (a condition referred to asfragmentation).Ifastreamalignmentcrossesatransportationsystemalignment,thenasuitablecrossingisrequiredto provide continuity of the stream habitat across the transportation corridor. For ecologicalcontinuity, if a bridge or culvert crossing is provided, then the opening that accommodates thestreammust have awidth, slope, and surface treatment that provides for the free flow of theecologicaltrafficthroughthestructure. Inthiscase,theflowthroughthestructure includesthepassageofwater,sediment,andnaturaldebris,andinadditionboththeupstreamanddownstreammovementofaquaticorganisms. Moreover,terrestrialmovementalongthestreamcorridorisalsoimportanttoecosystemintegrity.Forhabitat continuity, the crossingsmustbedesigned tobe continuouswith thehorizontal andverticalalignmentof theupstreamanddownstreamchannel,toconvey the flowofsedimentandnaturaldebris aswell aswater, and to accommodate the full rangeofwildlife types, life stages,movementabilities,andmovementbehaviors found in thenearby stream system. Crossingsnotmeetingallthesecriteriawouldobstructthepassageofwildlifepotentiallyisolatingcriticalareasoftheecosystemfromeachotherandthusfragmentingwildlifehabitats.

Fromtheabovedescriptions,thecommonfeaturesofroadwaynetworksandstreamsystemsshouldbeapparent. Both are long, linear features of the landscape, and the transportation of materials andorganisms is fundamental to their function. The function of both systems is critically dependent onconnectivityacrossthelandscape.Tomaintaintheriparianecosystemofastream,organismsneedunhinderedaccesstoavarietyofhabitatsfoundnaturallyalongthehydrologicnetwork.Aquaticspeciesmustbeabletoaccessfoodsourcesandsafehavens thataredependenton their life stage.Youngorganismsneedprotection frompredators;matureorganismsneedamenablespawninggrounds.Organismsneed tobeable toescape temporarychangesinconditionscausedbynaturalormanmadeprocessesthatrenderanareauninhabitable(e.g.,siltationorchangesintemperature).Groupsoforganismsarehighlyvulnerableiftheyareisolatedinoneareabecausethepopulationbecomessusceptibletoinbreeding,localizedextinctions,anddiseaseduetoovercrowding.Differenttypesoforganismsmovethroughtheriparianecosystemindifferentways. Strongmigratoryfishcannavigateturbulentandrapidlyflowingreacheswithquickburstsofspeedbutrelyonstillwaterpoolstorestandregaintheirstrength.Residentfishareoftenweakswimmersunabletoovercomeevenminorobstacles. Turtlesandsalamandersrelyoncontinuityofthebanksandchannelsubstrateforsuccessfulmovement.Otheraquaticnonswimmerorganismsdependonsymbioticrelationshipswiththeswimmerstomovethroughthesystem.Thus,theabilityforwildlifetomoveisessentialformanyreasons,including: Access to feeding areas (needs vary not only among species, but with various lifestageswithin

species);

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Accesstoshelterandtorefugefrompredators(needsvarynotonlyamongspecies,butwithvariouslifestageswithinspecies);

Accesstocoldwaterhabitats(aquaticorganismsareoftensensitivetotemperature); Accesstoareaswithconditionssuitableforspawningandbreeding; Access to allow populations to exploit new habitats and to sustain natural population growth or

preventpopulationdecline; Interactionwithothergroupsofindividualstomaintaingeneticallyhealthypopulations.Obstructionofmovementthereforecanhaveadverseconsequencesnotonlytoindividualmembersofaspecies,butalsotolargerpopulationsofspeciesandassemblagesofspecies.Traditionally, roaddesignershaveaddressed thekeyelements thatprovide forpassageofpeopleandmaterialsalongtheroadwayatstreamcrossings. Thedesignershavealsoaddressedtheconveyanceofflowsalong the streamsat these crossings. To somedegree, themovementof sedimentandnaturaldebrishasbeentraditionallyaddressedindesignonlyinsofarasthesematerialsaffectstructuralintegrityor flow capacity,butnotwith conscientious regard for the role thesematerialsplay in the ecologicalconditionofthestreamsystem. Themovementofwildlifethroughthesecrossingsisnotwellunderstood(other than for a limited number of fish species at various lifestages) and has usually received littleattentioninthedesignofculvertsandbridges.Asaconsequenceofthedesignofcrossingstomeetprimarilystructuralandhydraulicrequirements,manycrossingshavebecomeobstructionstowildlifemovement.Hydraulicallyefficientstructurescancreateconditionsthatinterferewiththehydraulicandgeologicprocesses(e.g.,erosionanddepositionofsediment)thatoccurinnaturalchannels. Engineeredstructuresfrequentlycreateflowdepthsandvelocitiesthataquaticorganismscannotnegotiate. Hydraulicenergytransitionsattheinletsandoutletsofculvertsresultinimpassablehydraulicconditionsfororganisms,andalsoinphysicalalterationstothechannel,whichaffecttheabilityoforganismstomovefreelythroughthesystem. Forexample,thedissipationofenergyassociatedwithhighvelocitiesattheoutletofaculvertcommonlyresultsnotonlyinscourpoolformation,butalsoinchanneldegradationforsomedistancedownstream. Thiscanresultinaconditionknownasperching,depictedinFigure21.Overtime,adropdevelopsfromthebottomoftheculverttothelowflowwatersurfaceofthedownstreampool. Suchdropslimitthemovementofthoseorganismsthatcannotnegotiatethejumpfromthepooltothebarreloftheculvert.Figure

2

2depicts

some

of

the

following

conditions

at

culverts

(as

well

as

some

bridges)

that

result

in

obstructionofthemovementofwildlife: Outletdrops(perching),whichposestructuralbarrierstopassageofmanyaquaticorganisms; Dropsatculvertinlets,eitherasaresultofinitialinstallationorsubsequentchannelalteration,which

alsoposestructuralorhydraulicbarrierstopassage;

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Figure21. PerchedCulvertsFragmentAquaticHabitat.

Inadequate flow depths under ordinary low flow conditions (not due to drought),which do notprovideminimumdepthsessentialforaquaticorganismstomove;

High velocities under a varietyof flow conditions, ranging from low flows to seasonal high flows(especially flowsoccurringduringperiodsofmigration). Atprevailingvelocitiesduring theperiodwhentheyneedtomove,organismsmusthavesufficientswimmingabilityandendurancetomoveupstream;

Scouringanderosion; Cloggingbynaturalorurbandebris; Pond formation upstream of culverts as a result of clogging, sediment deposition, or inadequate

culvertsize;

Unnatural bed materials that either physically interfere with passage, or affect the movement

behavioroforganismseveniftheyarephysicallycapableofnegotiatingthepassage. Unnaturalbedmaterialsmayincludesyntheticmaterials,suchaspavedchannelsorconcreterubble,butcanalsoinclude rockripraporothernatural liningmaterialsthatsubstantiallydiffer insizeandgradationfromthenearbynaturalstreambed;and



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The lackofsufficientdrybankunderprevailingflowconditions. Theabsenceofbanksorshallow

streammargins inhibits the terrestrialmovementofanimals thatdonotuse thewater columnorstreambedmaterial(streamsubstrate)fortravel.

Figure22. ConditionsAffectingWildlifePassageatCulverts

Adequateaccommodationofwildlifepassagecalls forastreamcrossingdesignapproach thatprovideshydraulic and substrate conditions throughout the structure, to prevent or overcome the aboveconditions. Ideally,abridgeorculvertstreamcrossingshouldsafelycarrytrafficoverastructurallysound,hydraulically adequate structure, and in addition be essentially transparent to wildlife. TheMassachusetts River and Stream Crossing Standards were developed to meet this objective. ThestandardsdescribedinthischapterderivefromaStreamSimulationdesignapproachthataddressesthepotential impeding conditionsby providing a continuous natural or nearnatural channelwithin thecrossing,maintainingconnectivitywiththeexistingstreamsystem.The following references provide additional information on the importance of stream continuity, thepassage problems associatedwith stream crossing structures, and the rationale for designing streamcrossingsforwildlifemovement: MassachusettsDivisionofEcologicalRestoration,DepartmentofFish&GamesMassachusettsStream

CrossingsHandbook(DepartmentofFishandGame,June2005,availableatthewebsite:o http://www.mass.gov/dfwele/der/freshwater4/rivercontinuity/guidancedoc.htm

UniversityofMassachusettsRiverandStreamContinuityProjectwebsite:ohttp://www.streamcontinuity.org/index.htm

DesignofBridgesandCulvertsforWildlifePassageatFreshwaterStreams 11
http://www.mass.gov/dfwele/der/freshwater4%20/rivercontinuity/guidancedoc.htmhttp://www.mass.gov/dfwele/der/freshwater4%20/rivercontinuity/guidancedoc.htmhttp://www.mass.gov/dfwele/der/freshwater4%20/rivercontinuity/guidancedoc.htmhttp://www.mass.gov/dfwele/der/freshwater4%20/rivercontinuity/guidancedoc.htmhttp://www.mass.gov/dfwele/der/freshwater4%20/rivercontinuity/guidancedoc.htm


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2.2 Evaluating Existing Crossings Relative to Wildli fe Passage

ManyofMassDOTsprojectsinvolveimprovementstoorreconstructionofexistingroadsandbridges. Forreconstructionofexistingstreamcrossings,theselectionoftypeofstructurewilldepend,inpart,onthedegreetowhichtheexistingstructureaccommodatesthemovementofaquaticandnonaquaticwildlife.Ifanexistingstructureoffersareasonabledegreeofpassage,thentheoptionsfortheimprovementprojectmayincludeinkindreplacement. Iftheexistingstructureisabarriertoaquaticwildlifepassage,thenalternativesforreplacementshouldincludecrossingstructuredesignsorotherdesignmeasuresthatwouldmitigateforthiscondition.Theassessmentofanexistingstructureregardingitscapacitytopermitwildlifepassagemayrequireconsultationwithpersonswithexpertiseinaquaticandterrestrialpassage,includingearlycoordinationwithMassachusettsDepartmentofFishandGameandotheraffectedresourceagencies. Currentliteraturealsoincludesvariouscriteriaandmethodologiesforassessingwhetherconditionsatculvertsandbridgespermitwildlifemovement.InconjunctionwiththeissuanceoftheACOEComprehensivePermitforBridges(CPB),MassDOThascompiledasimplifiedratingchart,basedonascoringsystemdevelopedbytheMassachusettsRiverandStreamContinuityProject. TheMassDOTratingchartscoresanexistingorproposedstructureusingtheinformationcompiledfromafieldevaluationworksheet,alsodevelopedbytheMassachusettsRiverandStreamContinuityProject.ThefieldevaluationprocedurehasbeenappliedtoexistingcrossingsinseveralNewEnglandstatesfortheassessmentofcrossingsandtheevaluationofstreamnetworksforhabitatcontinuity. AppendixBincludestheMassDOTratingchart,aswellasacopyofthe2010versionoftheStreamContinuityProjectfieldevaluationworksheetandinstructions.4Projectplannersanddesignersmayusethisfieldevaluationandscoringmethodologytoassistinidentifyingthedegreeofpassageaffordedbyanexistingstructure. Plannersanddesignersmayalsoapplythisscoringmethodologytoproposeddesignsofreplacementstructures.Theprocedureconsistsofthefollowing:

Step1. Completethefieldevaluationform,followingtheinstructionspreparedbytheStreamContinuityProject.

Step2. Usingthecompletedworksheet,usetheMassDOTStreamCrossingStructuresRatingCharttodevelopanumericalratingoftheculvertorbridge,onascaleof0to10.

Step3. UsingtheRatingcompiledinSteps1and2determinethepassageclassificationofthestructurefromTable21.

4TheMassachusettsRiverandStreamContinuityPartnershiprevisedthefieldevaluationworksheetandinstructionsin2010. ItalsoisdevelopinganupdatedscoringsystemthatisunpublishedasofthedateofthisHandbook. TheMassDOTratingsystemhasbeenincorporatedintotheComprehensivePermitforBridges(termexpiresin2015).MassDOTwillconsiderincorporatingthemodifiedscoringsystemintofuturerevisionsofthisHandbookandfuturerenewals(ifapplicable)oftheCPB.

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Usingtheclassificationobtainedfromtheaboveprocedure,thedesignercandeterminewhethertheexistingstructureisabarrier,allowsforaquaticpassageonly,orallowsforwildlifepassage. ThedesignercanthenusethisinformationtoaddressthedesigncriteriaidentifiedinChapter3ofthisdocument.

Table21. PassageClassificationforExistingStreamCrossingStructures5

RatingScore PassageClassification Remarks0to1 SevereBarrier Thestructureisconsideredabarriertomostaquaticand

terrestrialwildlife.2 ModerateBarrier Thestructuremayprovidesomepassageforaquaticwildlife,

andislikelyabarriertoterrestrialwildlife. Furtherinvestigationisrequiredtodeterminetheextenttowhichitprovidesaquaticpassage.

3to5 MinorBarrier Thestructureislikelytoprovideaquaticwildlifepassage,buthaslimitedcapacityfornonaquaticspecies.

6to8 MeetsGeneralStandards ThestructureprovidesaquaticandterrestrialpassageconsistentwiththeGeneralStandardsoftheMassachusettsRiverandStreamCrossingStandards.6

9to10 MeetsOptimumStandards ThestructureprovidesaquaticandterrestrialpassageconsistentwiththeOptimumStandardsoftheMassachusettsRiverandStreamCrossingStandards.

Notethatifthecrossingstructureratesasamoderatebarrier,furtherinvestigationisneededtodeterminewhethertheculvertallowssufficientpassageofaquaticorganisms. Suchinvestigationmightinclude(butnotnecessarilybelimitedto)hydraulicevaluationrelativetopassagecriteriaforindividualspeciesofconcern(suchasmigratoryfishspecies). Coordinationwithaffectedresourceagenciesmayalsoberequired.MassDOTrecommendscoordinationwiththeDepartmentsEnvironmentalSectiontodeterminethescopeoffurtherinvestigationswarrantedbasedontheinitialfieldevaluation.

5SeepreviousFootnoteregardingfuturerevisionsofthisscoringandclassificationsystem.

6StructureswithaRatingScoreof8maymeetoptimumstandardswherereducedopenness(>1.64feet(0.5meter))andheight(>4feet(1.2meters))requirementsareapplicable.

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Designersmayconsiderothertoolsormethodologyavailableintheliteraturetoassistinevaluatingexistingcrossingstructuresfortheirabilitytoaccommodatefishandaquaticorganisms. Forexample,theUSDAForestServicehasdevelopedasoftwareprogramcalledFishXing(pronouncedfishcrossing)forevaluatingculverthydraulicsrelativetofishpassage.However,thismodelhaslimitationsforuseinMassachusetts,becauseitrequiresdetailedinformationonstreamhydrologythatmaynotbereadilyavailable,andthecurrentsoftwaredoesnotincludedataformanyofthenativefishspeciesfoundinNewEngland.IfdesignersproposetheuseofFishXing,othermodels,oralternativemethods,theyshouldconsultwithfisheriesbiologistsontheapplicabilityofthosemethods,thespeciesthatshouldbeconsidered,andtheswimmingspeedsandleapingcapabilitiesthatshouldbeusedintheevaluation. Also,notethatthissoftwarefocusesonfishpassage,anddoesnotnecessarilyaddresstheaccommodationofthefullrangeofwildlifespeciesconsideredinthisdesignguidance.

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2.3 Introduction to the Massachusetts River and Stream Crossing Standards

TheMassachusettsRiverandStreamCrossingStandardsrespondtoconcernsthatbridgesandculvertsdesignedaccordingtotraditionalhydraulicandstructuralcriteriaoftenresultinthedisturbanceofhabitatconnectivityandhindrancenotonlytofishpassage,butalsotothepassageofotheraquaticandterrestrialfaunaalongtheripariancorridor. Thestandardsseektoachievefishandotheraquaticorganismpassage,river/streamhabitatcontinuity,andterrestrialwildlifepassageatstreamcrossings. Theseobjectivesaddressthemovementoforganismsacrossthefullrangeofspeciesandlifestagesfoundalongnaturalstreamsystems.TheRiverandStreamContinuityPartnership,whichincludestheUniversityofMassachusettsAmherst,MassachusettsDivisionofEcologicalRestoration,DepartmentofFishandGame(RiverwaysProgram),andTheNatureConservancy,developedthestandards. AninitialdocumentwasissuedinAugustof2004.Subsequently,thedocumentwasrevisedandupdated,andissuedastheMarch1,2006versionincludedinAppendixAofthishandbook.7TheCrossingStandardsaregenerallybasedonanapproachtostreamcrossingdesignreferredtoasStreamSimulation. TheStreamSimulationdesignapproachendeavorstocreateconditionswithinaculvertorbridgeopeningthatreplicatetheconditionsfoundintheadjacentstream.Asaresult,thechannelthroughthecrossingwouldbeexpectedtomaintainthediversityofstructureandmaterialsinherentintheexistingstreamsystem,whichinturnpermitsthemovementofresidentandmigratoryspeciesoverawiderangeofflowconditionsinthestream.Thisdesignapproachprovidesforthedevelopmentofanaturalstreambed(orsubstrate)withinthecrossingstructure,whichiscontinuouswiththeupstreamanddownstreamchannel. Theapproachalsoprovidesacorrespondingwidthandheightofopeningtoensurethelongtermviabilityofthissubstrate,giventhefullrangeofhydraulicconditionsanticipatedforthestructure. Implicitinthisdesignapproachisthedevelopmentofacrossingthathasthefollowingcharacteristics: Itdoesnotconstrictflowsastheyenterthestructure,anddoesnotresultinsignificanthydraulicdrops

orjumpsupstreamof,within,orimmediatelydownstreamfromthecrossing; Itmaintainsvelocitiesandflowdepthsunderavarietyofflowconditionsatvaluessimilartothose

occurringintheadjacentnaturalchannel; Itprovidesbedmaterialsofthetypeandtextureoccurringintheadjacentstreambed,allowingfor

similarpassageconditionsfororganismsabove,on,andwithinthesubstrate;and

7AtthetimeofpublishingofthisHandbook,theMassachusettsRiverandStreamContinuityPartnershipisrevisingtheRiverandStreamCrossingStandards.MassDOTanticipatesafutureupdateofthisHandbookwillincorporatechangescorrespondingtothoserevisedStandards.DesignersshouldconsulttheUSArmyCorpsofEngineers,NewEnglandDistrictwebsite[http://www.nae.usace.army.mil/reg/]underStreamandRiverContinuityforthemostcurrentversionoftheStandardsapplicabletotheMassachusettsGeneralPermit.

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Itprovidesforterrestrialpassageofwildlifeduringnormalflowconditions(thatis,thoseconditions

whenthestreamisconfinedwithinitsbankfullchannelwidth).TheRiverandStreamCrossingStandardsoutlinespecificrequirementstointroducethisstreamsimulationapproachintothedesignofbridgesandculvertsatnewcrossingsandatlocationswhereexistingstructureswillbereplaced. Inaddition,theCrossingStandardsprovideforanopennessofthestructurethatwouldbeconducivetotheterrestrialmovementofwildlifealongtheimmediatestreamcorridorthroughthestructure. Figure23presentsaschematicrepresentationofaculvertthatincorporatesastreamsimulationdesign.

Figure23. StreamSimulationCulvertDesign

Table22presentsasummaryofthestandardsincludedintheMassachusettsRiverandStreamCrossingStandards. AppendixAcontainsacopyoftheStandards.Thestandardsareorganizedintothreemajorsubtopics,asfollows:

1. DesignStandardsforNewCrossings.2. DesignStandardsforCulvertReplacement.3. ConstructionBestManagementPractices.

TheDesignStandardsforNewCrossingsincludeGeneralStandardsandOptimumStandards.GeneralStandardsapplytofishbearingstreamsandriverswherethegoalistoprovidefishpassage,streamcontinuity,andsomewildlifepassage. TheGeneralStandardsareanticipatedtoapplytomoststreamcrossings.



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OptimumStandardsareintendedtoapplytostreamsinareasofparticularstatewideorregionalsignificance. TheOptimumStandardsprovideforagreaterdegreeofwildlifepassage,andastrongeremphasisontheuseofbridgespansforcrossings.Keyelementsofthestandards(GeneralandOptimum)fornewandreplacementcrossingsincludethefollowing:

Astrongpreferenceforbridgespans(whichcouldincludebottomlessculvertstructures). InthecaseofGeneralStandards,welldesignedembeddedculverts,whilenotpreferred,maybeappropriate;

Requirementthateachstructurespanthestreambedandbanks(1.2timestheriver/streambankfullwidth;seefurtherexplanationofthisparameterbelow);

Provisionofnaturalsubstratewithinthestructure(eitherbypreservingthestreambed,orbycountersinkingthestructureanddevelopmentofstreambedmaterialwithinthestructure);

Designofconstructedstreambedmaterialtoresultinvelocityconditionscomparabletothoseinthenaturalchannelunderavarietyofflows;and

Designofthestructurecrosssectiontoprovideaminimumopennesstofacilitatewildlifepassage. Calculationofopennessisdiscussedbelow.

Inadditiontotheserequirements,theMassachusettsStreamCrossingStandardsalsoaddressconstructionBestManagementPractices,toaddresspotentialimpactstostreamsduringtheinstallationofnewandreplacementcrossings.Designersshouldincludeconsiderationofwaterhandlingmethods,erosioncontrol,andsedimentcontrolasanintegralcomponentoftheselectionanddesignofstreamcrossingstructures.ItisimportanttonotethattheMassachusettsStreamCrossingStandardsprescribeminimumrequirementsforbridgesandculvertsforaddressinghabitatcontinuity,butthestandardsdonotincludedetaileddesignguidanceforachievingtheserequirements. Forexample,thestandardsspecifythecontinuityofsubstratematerialswithincrossingstructures,butdonotprovidespecificguidanceonthedesignofthismaterialforlongtermviability. Thedesignerofthestreamcrossingmustseekguidancefromothertechnicalresourcestodevelopabridgeorculvertdesignthatwillmeethydraulicandstructuralstandardsrequiredforhighways,whileaccommodatingthefluvialprocessesthataffectthemorphologyanddynamicstabilityofstreambeds. Laterchaptersofthishandbookdiscussdesignapproachesandtechnicalresourcesforaccomplishingsuchdesign.

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2.4 Determining the Bankfull Width of a River or Stream

Thebankfullwidthofastreamcomprisesakeyparameterinthedesignofastreamcrossingforhabitatcontinuity. TheRiverandStreamCrossingStandardsindicatethatthewidthofstreamcrossingstructureopeningshouldbeatleast1.2timesthebankfullwidthofthestreamchannel. Thisparametershouldbedeterminedbyevaluatingthestreaminthefield,whichrequiresabasicunderstandingofstreamgeomorphology. Insomecases,asdiscussedbelow,fielddeterminationmaynotbefeasiblebecauseofurbanimpactsorotherchanneldisturbance,inwhichcasealternativemethodsforestimatingbankfullwidthmaybenecessary. Engineersorscientistswithtrainingandexperienceinstreamassessmentshouldperformthisfieldwork.ArecommendedreferenceforfieldmethodologyistheUSDAForestServicepublicationStreamChannelReferenceSites:AnIllustratedGuidetoFieldTechnique(Harrelson,et.al.,1994). Variouspublicandprivateorganizationsoffertraininginfluvialgeomorphologyandinthefielddeterminationofbankfullstageandwidth. TheUSForestServicealsooffersaseriesoflearningmodulesonfourCDROMdisks,AGuidetoIdentificationofBankfullStageintheNortheasternUnitedStates(GeneralTechnicalReportRMRSGTR133CD). Thiselectronicpublicationandothertrainingvideosforthedeterminationofbankfullparametersareavailablethroughthefollowingcontact:

USDAForestServiceStreamSystemsTechnologyCenterRockyMountainResearchStation.2150CentreAve,Bldg.A,Suite368,FortCollins,CO80526.(970)2955983http://www.stream.fs.fed.us/publications/videos.html

Thebankfullwidthofastreamisthetopwidthofthewatersurfaceinachannelflowingatbankfulldischarge. Bankfulldischargeisthoughtofasthechannelformingorchannelmaintainingflow,orasasurrogateparameterfortherangeofflowsthatcontroltheformofachannel. Itcorrespondscloselytoeffectivedischarge theflowthattransportsthelargestamountofsedimentinthelongtermundercurrentclimaticconditions. Bankfulldischargeisdefinedasthatflowoccurringwhenstreamwaterjustbeginstooverflowontotheactivefloodplainadjacenttothechannel. Theactivefloodplainisgenerallyaflatareaadjacenttothechannelconstructedbythestreamandoverflowedbythestream. Therecurrenceintervalforsuchflowsistypicallyabout1.5years,butcanvarywidely. Bankfullstageistheelevationofthewatersurfaceatthepointwherethisoverflowontothefloodplainoccurs. SeetheUSDAForestServicereferencerecommendedaboveforfurtherdiscussionofbankfulldischargeanditsfieldindicators. Figure24illustratesbankfullwidthandstageforatypicalstream.Avarietyofindicatorscanhelpindeterminingthebankfullstageandcorrespondingbankfullwidthofastream. Theprimaryindicatoristheflat,depositionalsurfaceoftheactivefloodplain,wherethisfeatureis

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prominent. However,inareaswherethefloodplainispoorlydefinedorabsent,otherindicatorsmaybeusedtoestimatebankfullstageorcorroborateitselevation,includingthefollowing:8 Slopeortopographicbreaksalongthebank; Heightofdepositionalfeatures(especiallythetopsofthepointbars,whichdefinethelowestpossible

levelforbankfullstage); Changeinvegetation(especiallythelowerlimitofperennialspecies); Changeintheparticlesizeofbankmaterial,suchastheboundarybetweencoarsecobbleorgravel

withfinegrainedsandorsilt; Undercutsinthebank,whichusuallyreachaninteriorelevationslightlybelowbankfullstage;and Stainlinesorthelowerextentoflichensonboulders.Notethatwhileanumberoftheseparameterscanhelpcorroboratethedeterminationofbankfullstage,thebestindicatoristhedepositionalsurfaceofthefloodplain.OnNewEnglandStreams,itisnotunusualformostoftheotherindicators,includingsomematuretrees,tobelocatedonthebankatalowerelevationthanbankfullstage.

Figure24. BankfullChannelWidth

8Harrelson,et.al.,1994,p33.

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Whilefieldidentificationisthepreferredmethodforestimatingthebankfullstageofastream,thismethodreliesontheassumptionthattheobservedchannelrepresentsnatural,quasiequilibriumconditions,andisnotintheprocessofsignificantchange. Inwatershedswithchanginglanduse,instreamssubjecttoregulationbyupstreamimpoundments,orinstreamssubjecttorecenthydrologicdisturbancebyextremefloodeventsorothernaturaloccurrences,suchequilibriumconditionsmaynotexist. Inthesecases,alternativemethodsmayberequiredtoestimatebankfullstageandwidth. Inwatershedsundergoingextensivelanddevelopment,bankfullwidthmayevenbeindeterminate.Usingareferencestreamisanalternativewherethesubjectstreamhasbeentemporarilydisturbedorwherethedisturbanceislocalizedandnotduetoextensivewatersheddisturbance. Thismethodcomprisestheidentificationofacomparable,undisturbednearbystream,withsimilargeologicandhydrologiccharacteristics. Fielddatafromoneormoresuchreferencestreamscanbeobtainedtoestimateanticipatedconditionsatthesubjectstreamcrossing.Wherewatersheddisturbanceprecludestheuseoffielddataobtainedfromthesubjectstreamorasuitablereference,thedesignermayneedtomoreroughlyassessbankfulldischargebycomparingestimatesofstreamconveyancecapacitytoflooddischargeswithrecurrenceintervalsbetweenoneandfiveyears.Publisheddataonregionalrelationshipsofbankfullwidth/depth/dischargetowatershedsize(andothercharacteristics)canalsobeusefulincorroboratingestimatesofbankfulldischargefromothermethods.TheU.S.GeologicalSurvey(USGS)hasdevelopedregressionequationsforestimatingbankfullchannelgeometryanddischargeforstreamsintheNortheasternUnitedStates. Theequationsareusefulforinitialplanninganalysisandconceptualdesign. Fieldinvestigatorsmayalsousetheestimatesobtainedfromtheseequationstoassistinverificationoffieldassessmentofbankfullparameters. Table23presentstheUSGSequationsdescribingtherelationshipofbankfullwidth,stage,anddischargetowatershedarea.Designersshouldnotconsiderthefloodflowcapacityestimatesortheuseofregressionequationsasubstituteforanonthegroundevaluationofbankfullwidth,wherethephysicalevidenceallowsfieldidentification. DesignersshouldobtainaproperlyexecutedfieldassessmentofbankfullwidthtouseasabasisforselectinganddesigningstructuresasdiscussedinthisHandbook. FurtherinformationaboutdocumentingthisdataisincludedinChapter6oftheHandbook.

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Table23. EquationsforEstimatingBankfullChannelGeometryandDischargeforStreamsintheNortheasternUnitedStates

(Source:Bent,2006)

BankfullChannel

Parameter

Regression

Equation

9

Bankfullstreamwidth(ft) WBF=13.2635[drainagearea(mi2)]0.4459Bankfullstreammeandepth(ft) DBFmean=0.9951[drainagearea(mi2)]0.3012Bankfullstreamcrosssectionalareain(ft2) ABF=12.8552[drainagearea(mi2)]0.7537Bankfulldischarge(ft3/s) QBF=40.9545[drainagearea(mi2)]0.8448

9Theseequationsareapplicableforstreamswithdrainageareasrangingfrom0.20to332squaremiles. Atthetimeofpreparationofthisdocument,theUSGSisdevelopingregressionequationsspecifictostreamsinMassachusetts,andthedocumentpresentingtheseequationsisunderagencyreview. Forwatershedswithparametersfallingwithinthestatisticallimitsofthenewequations,theMassachusettsequationsshouldbeusedinsteadofthoselistedinTable22,whentheUSGSpublishesthem.

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2.5 Determining Openness

TheMassachusettsRiverandStreamCrossingStandardsspecifyminimumopennessvaluesforstreamcrossingstructures. Theopennessisdeterminedbydividingthecrosssectionalflowareaofthestructurebythelengthofthecrossing(measuredinthedirectionofstreamflow).10 Notethattheembeddedportionofthestructureisnotincludedinthecrosssectionalareacomputation.TheGeneralStandardsrequireanopennessvalueof0.82feet(0.25meters). Forexample,astructurewithalength(measuredinthedirectionofstreamflow)of40feet(12.2meters)wouldrequireanopenareaof32.8squarefeet(3.05squaremeters). Thisareamustbeprovidedabovethestreambedmaterialwithinthestructure. Figure25illustratestheopennesscomputationforseveraltypesofstructures.TheOptimumStandardsrequireagreateropennessvalue,andaminimumclearheightofopeningabovethestreambed. Anopennessvalueof2.46feet(0.75meters)andclearheightof6feet(1.8meters)arerequiredwhereconditionssignificantlyinhibitwildlifepassage(hightrafficvolumes,steepembankments,fencing,Jerseybarrierswithintheroadwaymedian,orotherphysicalobstructions). Ifsuchconditionsarenotpresent,thentheOptimumStandardscallforanopennessvalueof1.64feet(0.5meters)andclearheightof4feet(1.2meters).

Figure25.OpennessforCulvertsandBridges

10NotethatintheMassachusettsStreamCrossingStandardstheopennessispresentedinmetricunits;conversiontoEnglishunitsisprovidedinthisguidancedocument.



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2.6 Thresholds for Optimum Standards

TheMassachusettsRiverandStreamCrossingStandardsdescribeOptimumStandardswherethegoalistoprovidefishpassage,streamcontinuity,andwildlifepassage. Asstatedbythestandards,

Wherestreamcrossingsoccurorareplannedinareasofparticularstatewideorregionalsignificancefortheircontributiontolandscapelevelconnectednessorriver/streamecosystemsthatprovideimportantaquatichabitatforrareorendangeredspecies,optimumstandardsshouldbeappliedinordertomaintainriver/streamcontinuityandfacilitatepassageforfishandwildlife.

Accordingtothestandards,areasofparticularsignificancefortheircontributiontolandscapelevelconnectednessinclude,butarenotlimitedto,streamcorridorslinkingareasofsignificanthabitat(>250acres)inthreeormoretowns. Importantaquatichabitatforrareorendangeredspeciesincludes,butisnotlimitedto,riverandstreamsegmentsidentifiedbytheNaturalHeritageandEndangeredSpeciesProgram(NHESP)throughregulatoryrevieworthroughNHESPsBiomap2project.TheUSArmyCorpsofEngineers(USACE)MassachusettsGeneralPermit(MGP)andtheMassachusetts401WaterQualityCertificationRegulationsdonotcurrentlyreferencetheOptimumStandardsnorrequiretheirspecificapplication(seediscussionofRegulatoryContextbelow).However,MassDOTanticipatesthattheOptimumStandardsarelikelytobeconsideredbyregulatorypersonnelforguidanceinareaswherehabitatsareconsideredsignificantandwherehabitatswouldsupportrareandendangeredspecies.Therefore,thestreamcrossingdesignershouldreviewtheregionalsettingoftheprojectrelativetohabitatssupportiveofrareandendangeredspecies,aswellasareaswherestreamcorridorsconnectotherhabitatsconsideredsignificantbyNHESP. Theoccurrenceofsuchhabitatsshouldthenbeconsideredinthedesignofthestreamcrossing. ThedesignershouldconsultthefollowingreferencesregardingpotentialhabitatsthatcouldwarrantconsiderationofOptimumStandards:

MassachusettsNaturalHeritageAtlas,mapsforEstimatedHabitatsofRareWildlifeandCertifiedVernalPoolsandPriorityHabitatsofRareSpecies;refertothefollowingwebpage:http://.mass.gov/dfwele/dfw/nhesp/regulatory_review/priority_habitat/online_viewer.htm

NHESPBioMap2interactivemapandsupportinginformation,atthewebpage:http://www.mass.gov/dfwele/dfw/nhesp/land_protection/biomap/biomap_home.htm

DesignatedWildandScenicRiversinMassachusettshttp://www.rivers.gov/wildriverslist.html#ma

MassachusettsStreamContinuityProject,MappingofHighQualityStreamshttp://www.streamcontinuity.org/assessing_crossing_structures/prioritzing_streams.htm

TheMassachusettsRiverandStreamContinuityProjectwebsitelistedaboveidentifieshighqualitystreamsusingGISdatabasedontheotherlistedsourcesofinformationandrelateddata.MassDOTrecommendscontactingthisproject,checkingitswebpageathttp://www.streamcontinuity.org/index.htm,andalsocontactingtheMassachusettsDepartmentofFishandGameDivisionofEcologicalRestoration,RiverwaysProgram,toobtainthemostrecentinformationonthemappingandclassificationofMassachusettsstreams.MassDOTalsorecommendsconsultingthese

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programsforinformationtheyhavecompiledregardingprioritizationofstreamsandcrossingsforimprovementofstreamcontinuity.TheLinkingLandscapesforMassachusettsWildlifeprojectisaninteragencyinitiativebyMassDOT,MassWildlife,andUMassAmhersttoidentifyandcategorizesitespecificwildliferoadwaymortalityhotspots,withanemphasisonherpetofauna.DesignersshouldconsultwithMassDOT,MassWildlife,orUMassAmherstprojectcoordinatorstodeterminewhetherasitespecificwildliferoadwaymortalityhotspotexistsattheprojectsite. TheCriticalLinkagesprojectcurrentlyunderwayatUMassAmherstwilleventuallyprovidemapsofareasofstatewideandregionalimportanceforlandscapescaleconnectivity.Designersshouldalsoconsultwithregulatoryagenciesearlyintheprojectdevelopmentphase,todiscussapplicablepermittingrequirements,andtoidentifyrelevanthabitatconditionsattheprojectsite,withinthewatershedofthestreamcrossing,andwithinthegeneralregionoftheproject.

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2.7 Regulatory Context

Relativetotheaccommodationofwildlifeatstreamcrossings,theregulationsofprimaryconcernincludethefollowing:FederalRegulations:

Section10oftheRiversandHarborsActof1899;and Section404oftheCleanWaterAct(CWA).

MassachusettsRegulations: 314CMR9.00:401WaterQualityCertificationforDischargeofDredgedorFillMaterial,Dredging,

andDredgedMaterialDisposalinWatersoftheUnitedStatesWithintheCommonwealth(401Regulations);and

310CMR10.00:WetlandsProtectionActRegulations.FederalrequirementsapplicabletotheprovisionofwildlifeaccommodationatstreamcrossingsaregenerallyspecifiedintheUSArmyCorpsofEngineers(USACE)MassachusettsGeneralPermit(MGP),andalsointheUSACEMassachusettsDepartmentofTransportationComprehensivePermitforBridges(CPB),anindividualprogrammaticpermitissuedforMassDOTbridgereplacement/reconstructionactivities.AppendixCcontainsacopyoftheMGP. AppendixDincludesacopyoftheCPB.Table24(attheendofthischapter)presentsguidancefordeterminingwhetheraparticularbridgeprojectiseligibleforconsiderationundertheMGPCategory1,MGPCategory2,ortheCPB. ProjectswithinUSACEjurisdictionthatdonotfallintooneofthesecategorieswouldrequireapplicationforaSection404IndividualPermitfromtheCorps.MassDOTsrecommendedorderofpreferenceforthepermiteligibilityofaprojectisasfollows:

1. ProjectisdesignedtobeeligibleundertheCPB(documenteligibility;provideWorkStartNotificationFormtotheNewEnglandDistrict,USACE).

2. ProjectisdesignedtobeeligibleasCategory1(noapplicationrequired)undertheMGP(documenteligibility;provideCategory1FormtotheNewEnglandDistrict,USACE).

3. ProjectisdesignedtobeeligibleasCategory2(applicationrequired)undertheMGP(completeapplicationtoUSACE).

4. ProjectissubjecttoaSection404IndividualPermit(completeapplicationtoUSACE).NotethatcertainmaintenanceactivitiesarenotprohibitedorsubjecttoregulationunderSection404oftheCWA. PleaserefertoMGPsAppendixAEndnote15,foradetaileddiscussionofhowCorpsregulationsaddressmaintenance.

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Massachusettsrequirementsapplicabletocrossingsaresetforthinthe401Regulations,whichcrossreferencetheWetlandsProtectionActRegulations. AppendixEincludesacopyofthe401Regulations.Theapplicablefederalandstatepermitrequirementsarebrieflydiscussedinthefollowingsections.Underbothfederalandstateregulatorysettings,earlycoordinationbetweenprojectdesignersandtheaffectedregulatoryandnaturalresourceagenciesisanimportantcomponentofthecrossingstructureselectionanddesignprocess. Earlycoordinationwillassistbothdesignandregulatorypersonnelinidentifyingkeyissuesthatwillneedtoberesolvedinordertoachieveregulatorycompliance.2.7.1 US Army Corps of Engineers Massachusetts General Permit

TheNewEnglandDistrictoftheU.S.ArmyCorpsofEngineers(USACE)issuedtheMassachusettsGeneralPermit(MGP)fortheCommonwealthofMassachusettsinJanuary2010. TheMGPexpeditesreviewofactivitiesinwatersoftheUnitedStatesthatwouldhaveminimalindividualandcumulativeimpactsontheaquaticenvironmentwithintheCommonwealthofMassachusetts. TheMGPcoversactivitiesinresourceareasregulatedbytheUSACEunderSection10oftheRiversandHarborsActof1899,Section404oftheCleanWaterAct(CWA),andSection103oftheMarineProtection,ResearchandSanctuariesAct. TheMGPestablishesconditionsforCategory1(noapplicationrequired)andCategory2(applicationrequired)activities. AcopyoftheMGPisincludedasAppendixCofthisguidance.TheMGPincludesGeneralCondition21.StreamCrossingsandWork. Thetermsofthisconditionareofparticularnoteregardingthedesignofnewandreplacementstreamcrossings,andarequotedatlengthbelow:

(a)Alltemporaryandpermanentcrossings11ofrivers,streams,brooks,etc.(hereonreferredtoasstreams)shallbesuitablyculverted,bridged,orotherwisedesignedtoi)withstandandpreventtherestrictionofhighflows,andii)notobstructthemovementofornotsubstantiallydisruptthenecessarylifecyclemovementsofthosespeciesofaquaticlifeindigenoustothewaterbody,includingthosespeciesthatnormallymigratethroughthearea,beyondtheactualdurationofconstructionunlesstheactivitysprimarypurposeistoimpoundwater.(b)AnyworkthattemporarilyorpermanentlyimpactsupstreamordownstreamfloodconditionsorpermanentlyimpactswetlandsmustbereviewedunderCat.2.TheMassachusettsDamRemovalandtheWetlandRegulationsmaybeusedasareference.[Note:(c)(l)belowonlyapplytoInlandWatersandWetlands(c)FornewstreamcrossingstoqualifyforCategory1:

11TheMGPdoesnotapplytoconstructeddrainagesystemsdesignedprimarilyfortheconveyanceofstormwaterorirrigation.

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i.Theseshallbedesignedandconstructed12 toconformtotheGeneralStandardscontainedintheversionoftheMassachusettsRiverandStreamCrossingStandardsonourwebsite.ii.Theseshallbeatleast5feetwideatgroundleveltoensurethatGeneralStandard3ismetforsmallstreams.iii.Spans13arerequiredtoavoidorcauseminimaldisruptiontothestreambed.Footingsandabutmentsshallbelandwardof1.2timesbankfullwidth(seeGeneralStandard3in(c)above).Tothegreatestextentpracticable,workinthestreamshallbeminimized,anddesignandconstructionshallallowthestreambedsnaturalstructureandintegritytoremainintact.Anyfillorexcavationofthestreambedbelowbankfullwidthotherthanfootings,supportpilings,andworkspecifiedin21(h),21(i),21(l)iiand21(l)iii,requiresCategory2reviewand,unlessdemonstratedotherwise,streamsimulationasnecessarytorestoreorestablishsubstrateandbanksinthespanstructureandworkareatomatchthecharacteristicsofthesubstrateandbanksinthenaturalstreamchannel.13

(d)Forreplacementstreamcrossings:i.Theseshouldbedesignedandconstructed14 toconformtotheGeneralStandardscontainedintheversionoftheMassachusettsRiverandStreamCrossingStandardsonourwebsite(seeAppendixFoftheMGP).ThisisrecommendedtoensurecompliancewithGC21(a)andGC21(b)above.ii.CompliancewithGeneralStandards2and4isrequiredtoqualifyforCategory1.iii.ReplacementcrossingsonthefollowinghighqualitystreamsegmentsarenoteligibleforCategory1:NHESPLivingWaterCores,NHESPBioMapcores,ACECs,AnadromousFishRuns,andColdWaterFisheries.Theseareshownat:www.streamcontinuity.org/assessing_crossing_structures/prioritzing_streams.htm

(e)CulvertextensionsdonotqualifyforCategory1andmustbereviewedbytheCorps.(f)FornewstreamcrossingsnoteligibleforCategory1,andforreplacementcrossings,applicantsshouldusetheleastintrusiveandenvironmentallydamagingmethodtoconstructnewandreplacementstreamcrossingsfollowingthissequentialminimizationprocess:1)Spanswithnostreamimpacts,2)Spanswithstreamimpacts,and3)Embeddedculvertswithstreamsimulationorlowslopedesign.

12SeeAppendixFoftheMGPfordesignandconstructionmethodology

13ForpurposesofthisGP,spansarebridges,3sidedboxculverts,openbottomculvertsorarchesthatspanthestreamwithfootingslandwardofbankfullwidth.

14SeeAppendixFoftheMGPfordesignandconstructionmethodology.

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(g)ThepermitteeshallmaintaintheworkauthorizedhereiningoodconditionandinconformancewiththetermsandgeneralconditionsofthispermittofacilitateaquaticlifepassageasstatedinGC21a.Culvertsthatdevelophanginginletsoroutlets,resultinbedwashout,orastreamthatdoesntmatchthecharacteristicsofthesubstrateinthenaturalstreamchannelsuchasmobility,slope,stability,confinementwillrequiremaintenanceorrepairtocomplywiththisGC.(h)Paragraphs(b)(g)abovedonotapplyto:

i.Temporaryspans.Temporaryspansshallberemovedwithin180days.ii.Temporarystreamcrossingsthatarentspans(typicallyculverts).ToqualifyforCategory1,thesemustbedesignedinaccordancewith16below.Category2projectsshouldfollow26below:

1.Installedoutsideofthetimeofyear(TOY)restrictionsspecifiedinGC21(m)belowandmustberemovedbeforethebeginningoftheTOYrestrictionofthatsameseason.ThosethatwillremainintotheTOYrestrictionwillrequireCategory2review.2.Placedongeotextilefabricorothermaterialwherepracticabletoensurerestorationtotheoriginalgrade.Soilmaynotbeusedtoconstructorstabilizethesestructuresandrockmustbelargeenoughtoallowforeasyremovalwithoutdisruptingthestreambed.3.Designedandmaintainedtowithstandandpasshighflows.Waterheightshouldbenohigherthanthetopoftheculvertsinlet.Aminimumculvertdiameteroftwofeetisrequiredtopassdebris.Culvertsmustbealignedtopreventbankerosionorstreambedscour.4.Equippedwithenergydissipatingdevicesinstalleddownstreamifnecessarytopreventscour.5.Designedandmaintainedtopreventsoilfromenteringthewaterbody.6.Removeduponthecompletionofwork.Impactstothestreambedorbanksrequiresrestorationtotheiroriginalconditionusingstreamsimulationmethods.15

(i)Temporarystreamcrossings(seehabove)orcofferdamsshallbeusedforequipmentaccessacrossstreams(seeAppendixFoftheMGP).Note:Areasoffilland/orcofferdamsmustbeincludedintotalwaterway/wetlandsimpactstodeterminethereviewcategoryinAppendixA(oftheMGP).

15SeeAppendixFoftheMGPfordesignandconstructionmethodology.

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(j)Maintenanceandreplacementsofstreamcrossings.Anexistingstreamcrossingmustbeauthorizedandincompliancewithallconditionsofitsauthorization(s)toqualifyformaintenancenotsubjecttoregulation.SeeAppendixA(oftheMGP),Endnote15.(k)Projectsusingsliplining(retrofittinganexistingculvertbyinsertingasmallerdiameterpipe),plasticpipesandHighDensityPolyethylene(HDPE)pipesdonotqualifyforCategory1,eitherasnewworkormaintenanceactivities.(l)ForCategory1work:i)Noopentrenchexcavationinflowingwaters.ii)Managementtechniquessuchastemporaryflumepipes,culverts,cofferdams,etc.mustbeusedtomaintainnormalflowswithinthestreamboundarysconfines.iii)Waterdiversionsmaybeusedimmediatelyupanddownstreamoftheworkfootprint.SeeAppendixA(oftheMGP),Endnote4.(m)ForprojectsthatotherwisemeetthetermsofCategory1,instreamconstructionworkshallnotbeconductedduringthetimeofyear(TOY)restrictionsspecifiedintheMADMFdocumentreferencedinGC24.Forstreamsnotindicatedinthisdocument,workmaynotbeconductedfromOctober1toJune30.ProjectsproposedduringtheseTOYrestrictionsareineligibleforCategory1,regardlessofthewaterwayandwetlandfilland/orimpactarea.

Inadditiontotherequirementsatstreamcrossings,theMGPalsorequireshydraulicandecologicalconnectivityatwetlandcrossings,asprovidedbyGeneralCondition22:

(a)Alltemporaryandpermanentcrossingsofwetlandsshallbesuitablyculverted,bridged,orotherwisedesignedto:

i)Withstandandpreventtherestrictionofhighflows,ii)Notobstructthemovementofornotsubstantiallydisruptthenecessarylifecyclemovementsofthosespeciesofaquaticlifeindigenoustothewetland,includingthosespeciesthatnormallymigratethroughthearea,beyondtheactualdurationofconstructionunlesstheactivitysprimarypurposeistoimpoundwater.

(b)ToqualifyforCategory1,newandreplacementwetlandcrossingsthatarepermanentshallbeculverted,spannedorbridgedinsuchamannerastopreservehydraulicandecologicalconnectivity,atitspresentlevel,betweenthewetlandsoneithersideoftheroad. Tomeetthisrequirement,werecommendthatculverts,spansorbridgesbeplacedatleastevery50feetwithanopeningatleast2feethighand3feetwideatgroundlevel. Closedbottomculvertsshallbeembeddedatleast6incheswithanaturalbottom. Inaddition,seeAppendixFforMassDEPsstandards.(c)Inthecaseofnoncompliance,thepermitteeshalltakenecessarymeasurestocorrectwetlanddamageduetolackofhydraulicconnectivity.(d)Anyworkthatpermanentlyimpactsflooding,wetlandsoneithersideofthewetlandcrossing,orwetlanddrainagefromtheupgradientsideofthewetlandcrossingdoesnotqualifyforCategory1.

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Insummary,theMGPrequirestemporaryandpermanentcrossings(neworreplacement)tomaintainmovementofindigenousaquaticlife(Condition21(a)),andestablishesconditionsforcomplianceforthoseprojectsfallingwithinCategory1orCategory2reviewunderthisgeneralpermit.16ForprojectssubjecttoCorpsjurisdictionthatdonotmeettheseconditions,theprojectsmayrequireanindividualpermit. ForMassDOTbridgeprojectsmeetingcertainconditions,theprojectsmayqualifyforpermittingundertheCorpsComprehensivePermitforBridges(discussedbelow).DesignersshouldcheckthefollowingwebsiteforthecurrentpostedversionoftheMGP,andconsultwithMassDOTsEnvironmentalSectiontoconfirmcurrentpermittingrequirementsunderSection404oftheCWA:

http://www.nae.usace.army.mil/reg2.7.2 US Army Corps of Engineers Comprehensive Permit for Bridges

TheNew

England

District

of

the

USACE

issued

the

Massachusetts

Department

of

Transportation

ComprehensivePermitforBridges(CPB)inAugust,2010withitstermexpiringJuly31,2015. TheCPBisaprogrammaticpermitthatcoversbridgerepair,replacement,andreconstructioniftheprojectsmeetcertainstandardsorconditions. AcopyofthispermitisincludedinAppendixDofthishandbook.WorkmaybeperformedoneligiblebridgesuponfilingofanoticewiththeNewEnglandDistrict,USACE,priortocommencingwork. EligiblebridgesmusthaveaMassDOTBridgeNumber;bothbridgespansandcertainculvertsmaythereforebeeligibleiftheymeetthiscriterion,inadditiontotheotherconditionsstipulatedinthepermit. TheStandardsandConditionsfortheComprehensivePermitforBridgesspecifythatthefollowingprojectsarenoteligibleunderthispermit,andmustbereviewedundertheMGP(discussedintheprevioussection)orunderanIndividualPermitapplication:

Morethan5,000squarefeetofimpacttovegetatedwetlandsorwaters; BridgescrossingaFederallydesignatedWildandScenicRiver; ProjectsinvolvingworkonCorpspropertiesandCorpscontrolledfloodeasementssuchasthe

CharlesRiverNaturalValleyStorageArea; Proposedbridgereplacementswherethelowchordwillintersectthe10yearfloodelevation; BridgesthathavebeenidentifiedbytheMassachusettsOfficeofCoastalZoneManagementas

potentiallycausingrestrictionstotidalflows; Projectswhichmayaffectanyfederallylistedendangeredspeciesortheirhabitat; AnyprojectlocatedinanhistoricdistrictorwheretheremaybeaneffecttoanyNationalRegister

eligiblepropertyunlessimpactshavebeenaddressedpursuanttotheProgrammaticAgreement(PA)betweenFederalHighwayAdministrationandtheStateHistoricPreservationOfficeroranysubsequentCorpsofEngineersPAtosatisfytherequirementsofSection106oftheNationalHistoricPreservationAct;

16SeeAppendixAoftheMGP,underI.INLANDWATERSANDWETLANDS,(c)RIVER/STREAM/BROOKWORK&CROSSINGSandWETLANDCROSSINGSforalistofcriteriafordistinguishingCategory1fromCategory2activitiesinnontidal,nonSection10watersforstreamandwetlandcrossingprojects.

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Forabridgespanorarch:o Theproposedopenspanwaterwaywidthatgroundlevelislessthantheexisting

structuresspan.However,thisqualificationdoesnotapplyifthenewspanwidthisatleast1.2timesthegeomorphicbankfullwidthofthestream;

oThe

proposed

bridge

span

or

arch

span

constricts

flow

over

a

bedrock

dominated

streambed,resultinginimpassablestreamflowvelocities;

o Thereisadamorotherstructuralelement(otherthanabridgeabutmentorpier)thatobstructsthechannelwithinthefootprintoftheproposedbridgespanorarchspan;

o Aproposedbridgethatconsistsofaculvertthatisratedasamoderateorseverebarriertoaquaticorganismpassage.AmoderateorseverebarrierisastructurewithaCrossingRatingoflessthan3,basedonanevaluationusingtheMassDOTStreamCrossingStructuresRatingChart.17

Designersshoulddocumenteligibilityforbridgeprojectsproposedforimplementationunderthispermit.EligibleprojectsmustmeettheStandardsandConditionssetforthinthepermit.DesignersshouldalsonotetheStandardsandConditionsoftheComprehensivePermitforBridgesincludeanumberofmeasuresformanagementofpotentialconstructionimpacts,includingbutnotlimitedto:

Watercontrolmeasuresduringconstruction. TheCPBincludesFigures18presentingspecificBestManagementPracticesforwaterhandlingandturbiditycontrolduringconstruction;

Constructiontimingandsequencing;and Constructiondebriscontainment.

DesignersshouldnotetheMassachusettsDEP401WaterQualityCertificationforthispermitalsoprovidesforspecificconditionsincluding,butnotlimitedtothefollowing:

Conditions

for

temporary

fills;

Turbiditycontrol; Erosionandsedimentcontrol,includingmeasuresregardingtemporarystabilization,fertilization,

andmulching; Restrictionsonequipmentaccesswithinwetlandsandwaterways; Prohibitionoftrenchexcavationinflowingwaters;and Inspectionaccessforregulatorypersonnel.

2.7.3 Massachusetts 401 Water Quality Certification Regulations

TheMassachusettsDEPissuedrevisedregulationsat314CMR9.00:401WaterQualityCertificationforDischargeofDredgedorFillMaterial,Dredging,andDredgedMaterialDisposalinWatersoftheUnitedStatesWithintheCommonwealth(401Regulations)onDecember26,2007,andsubsequentrevisionsonJanuary2,2008. Thisregulationgovernstheplacementoffillinwetlandsandwaterways,inadditiontoregulatingdredgingactivityandthehandlingofdredgedmaterials. Under314CMR9.00,certainprojects

17SeeAppendixBofthishandbook.

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donotrequirefilingofaseparate401Certificationapplication,providedtheprojectsmeetspecifiedconditions. Thisincludesthefollowing(see314CMR9.03):

ActivitiesareconductedincompliancewiththeWetlandsProtectionAct,receivingaFinalOrderofConditionsunder310CMR10.00;

Theworkresultsinthelossoflessthan5,000squarefeetofcumulativeimpactonborderingandisolatedvegetatedwetlandsandlandunderwater;

TheFinalOrderofConditionsprovidesforatleast1:1replacementofborderingvegetatedwetlands;

TheactivityconformstotheWaterwaysCrossingrequirementsatGeneralCondition21intheProgrammaticGeneralPermit;and

Theworkisnototherwisesubjecttoaseparatepermitapplicationunderotherprovisionsofthe401Regulations.

Thus,forprojectssubjecttoreviewandpermittingundertheWetlandsProtectionAct(theforumforreviewofmostwaterwaycrossingprojectsinMassachusetts),theDEPhasidentifiedtheSection404PGP(whichhasnowbeensupersededbytheMGPdiscussedinaprevioussection)astheapplicablestandard.314CMR9.04requiresa401WaterQualityCertificationApplicationforcertaintypesofprojects,including(butnotlimitedto)activitiesthatresultindredgingorfillinginanyOutstandingResourceWater(ORW),oractivitiesinvolvinggreaterthan5,000squarefeetofcumulativelossofborderingandisolatedvegetatedwetlandsandlandunderwater. Ifanapplicationisrequired,thenSection9.06setsforthcriteriafortheevaluationoftheapplication. 9.06(3)governsthedischargeofdredgedorfillmaterialinORWs,includingSection9.06(3)(f):

Constructionofutilities,publicorprivateroadwaysorotheraccessexceptasspecifiedin314CMR9.06(3)(e),railroadtrackandrailbedsandfacilitiesdirectlyrelatedtotheiroperation. Theseactivities

require

use

of

a

span

or

other

bridging

technique,

unless

the

Department

determines,

basedoninformationcontainedinaDepartment401alternativesanalysis,aCorpsofEngineersSection404alternativesanalysis,oranEnvironmentalImpactReportandtheSecretary'scertificate,thatthisalternativeisnotpracticable,wouldnothavelessadverseimpactontheaquaticecosystem,orwouldhaveothersignificantadverseenvironmentalconsequences.

Thus,forroadwayprojectssubjectto401WaterQualityCertificationreviewandinvolvingacrossingofanORW,aspanorotherbridgingtechniqueisrequiredunlessanalternativehasbeendocumentedandapprovedundertheapplicationprocess. (Note:residentialsubdivisionroadwaysarecoveredunderotherprovisionsof314CMR9.06.)

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3.0 Criteria for Wildlife Passage at Bridges and Culverts

ThischapteroutlinesMassDOTscriteriaforaddressingwildlifeaccommodationconsiderationsatroadwaycrossingsoffreshwaterstreamsonaprojectbyprojectbasis. Thecriteriavary,dependingonwhethertheprojectconsistsofmaintenanceactivity,replacement/reconstruction,orprovisionofanewstreamcrossingstructure. Foreachofthesebroadcategoriesofactivities,therearedifferingopportunitiesandconstraintsfortheprovisionofwildlifepassage. Subsequentchaptersthendiscussindetailthedesignmethodologiesandpertinentconstraintsformeetingthesecriteria.ThefollowingpagesincludeguidanceintendedtooutlineBestPracticesforprovidingwildlifeaccommodationatfreshwaterstreamcrossings,whilerecognizingconstraintsthatgoverntheselection,design,construction,andmaintenanceofbridgesandculverts. Theguidanceintendsthesepracticestocomplywithregulatoryrequirementsapplicabletonewandreplacementstructuresatriverandstreamcrossings,includingapplicablemeasuresoftheMassachusettsRiverandStreamCrossingStandards.ThischapterdescribescriteriaforconsiderationofwildlifepassageatroadwaystreamcrossingsforthefollowingbroadcategoriesofMassDOTactivities:

Maintenancerepair/reconstruction:MassDOTmaintainsroadwayinfrastructuretoprovideforthecontinuingsafetyandserviceabilityofexistingroadways. Theseactivitiessometimesrequirerepairorreplacementofpartorallofanexistingculvertorbridgestructure,topreventafailureoftheroadsurface,supportingstructure,andembankment.

Reconstruction:ManyMassDOTprojectsareplannedanddesignedforthereconstructionandreplacementofroadwaysandroadwaystructures(includingbridgesandculvertsatstreamcrossings)toimproveandupgradeexistingroadwaystomeetevolvingtransportationneedsandsafetystandards. TheseprojectsproceedundertheDepartmentsdevelopmentanddesignprocess,andprovideopportunitiestoaddresswildlifepassageinconjunctionwiththeotherprojectobjectives.

Newconstruction:MassDOTundertakesconstructionofnewroadwaystomeetthetransportationneedsoftheCommonwealthofMassachusetts.Wheretheseprojectsrequirenewstreamcrossings,theselectionanddesignofstructureswillrequireintegrationofwildlifeaccommodation.

Thefollowingsubsectionsdescribethecriteriaapplicabletotheseactivities:3.1.Criteriaformaintenanceactivities;3.2.Criteriaforreplacementsofexistingstreamcrossingsthatarenotconsideredmaintenance

activities;3.3.Criteriaforconstructionofnewstreamcrossings;3.4.Exceptions;

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3.5.Requiredconstraintsanalysis;and3.6.Orderofpreferenceofalternatives.

Subsequentchaptersofthisguidancedocumentprovideadditionaldetailedinformationtosupportthisplanninganddesignapproach,including:

Designmethodologiesforwildlifeaccommodationatbridgesandculverts(Chapter4), Constraintstoconsiderintheapplicationofthesemethodologies(Chapter5);and ImplementationofthecriteriathroughMassDOTsdevelopmentanddesignprocess(Chapter6).

3.1 Criteria for Maintenance Activities

MassDOTconductsmaintenanceactivitiestorespondtoconditionsthatcouldimminentlyaffecttheintegrity

of

the

roadway,

associated

structures

(such

as

bridges

and

culverts),

and

the

supporting

embankment. Bytheirnature,MassDOTdoesnotandcannotconducttheseactivitiesasprojectsunderthedevelopmentanddesignprocessthathasbeenestablishedforMassDOTsroadwayimprovementprojects. Instead,MassDOTimplementstheseac

Documents

Design Bridges Culverts Wildlife Passage 122710