Sediment Load from Major Rivers into Puget Sound and its ... · sediment-transport pathways ......
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Figure 1. Benefits and threats of river sediment to ecosystems and society. Drainage Basins Deltas and Marshes Source of contaminants Enables marsh accretion, buffers sea-level rise Excessive sediment buries habitat Lack of sediment, inundation because of sea-level rise Beaches Forms beaches Lack of sediment leads to erosion Mountains Source of sediment Extreme events deliver too much sediment Provides nutrients and soil Source of sediment Forms berms (barriers) to floods Buries vegetation Offshore/Marine Excessive sediment buries habitat, fragments ecosystems Creates turbid water, loss of light for aquatic vegetation Rivers Flood Plains Creates spawning habitat Provides nutrients to benthic habitats Changes in sediment size affect spawning habitat Channel deposition increases flood risk Benefit Threat EXPLANATION U.S. Department of the Interior U.S. Geological Survey Fact Sheet 2011–3083 August 2011 Sediment Load from Major Rivers into Puget Sound and its Adjacent Waters Jonathan A. Czuba, Christopher S. Magirl, Christiana R. Czuba, Eric E. Grossman, Christopher A. Curran, Andrew S. Gendaszek, and Richard S. Dinicola Printed on recycled paper Highlights • Each year, an estimated load of 6.5 million tons of sedi- ment is transported by rivers to Puget Sound and its adjacent waters—enough to cover a football field to the height of six Space Needles. • This estimated load is highly uncertain because sediment studies and available sediment-load data are sparse and historically limited to specific rivers, short time frames, and a narrow range of hydrologic conditions. • The largest sediment loads are carried by rivers with glaci- ated volcanoes in their headwaters. • Research suggests 70 percent of the sediment load delivered to Puget Sound is from rivers and 30 percent is from shoreline erosion, but the magnitude of specific contributions is highly uncertain. • Most of a river’s sediment load occurs during floods. Why is River Sediment Important to Puget Sound? Rivers carry freshwater into Puget Sound as well as sediment and other materials, such as wood, important to estuarine and nearshore habitat, aquatic ecology, and water quality. Historical channelization of rivers and deltas has altered sediment-transport pathways by restricting sediment delivery to flood plains and redirecting sediment offshore. Paradoxically, sediment is both a benefit and a threat to ecosystems and society (fig. 1). Sufficient, but not excessive, amounts of sediment are important resources for beaches, deltas, and other coastal habitats that sustain ecosystems, vegetation, and animals that people depend on. Excessive amounts of sediment can place stress on a variety of species and habitats. For example, eelgrass meadows, which provide important nearshore marine habitat for fish, shellfish, and invertebrates, as well as food for waterfowl and detritus feeders, can be buried or fragmented by increased sediment delivery associated with river-delta channelization, like those offshore of the Skagit River (Grossman and others, 2011). In contrast, when sediment delivery is depleted, nearshore critical habitat and beaches can be eroded by natural coastal processes and lost (Warrick and others, 2009). Changes in sediment grain-size composition also affect ecosystems. For example, many shellfish beds and forage-fish spawning beaches depend on a specific sediment grain-size composition that is linked to land-use activities and hydrologic conditions that release and carry sediment to Puget Sound (Gelfenbaum and others, 2009). Water quality, nearshore and offshore habitats, and aquatic-ecosystem health are affected by contaminants and nutrients that preferentially adsorb to fine sediments and are delivered to Puget Sound. Once present, these contaminants can bioaccumulate in fish and shellfish making these seafoods toxic for human consumption.
Transcript of Sediment Load from Major Rivers into Puget Sound and its ... · sediment-transport pathways ......
Figure 1. Benefits and threats of river sediment to ecosystems and society.
Drainage Basins
Deltas and Marshes
Source of contaminants
Enables marsh accretion, buffers sea-level riseExcessive sediment buries habitatLack of sediment, inundation because of sea-level rise
BeachesForms beachesLack of sediment leads to erosion
MountainsSource of sedimentExtreme events deliver too much sediment
Provides nutrients and soil
Source of sediment
Forms berms (barriers) to floods
Buries vegetation
Offshore/Marine
Excessive sediment buries habitat, fragments ecosystemsCreates turbid water, loss of light for aquatic vegetation
Rivers
Flood Plains
Creates spawning habitat
Provides nutrients to benthic habitats
Changes in sediment size affect spawning habitat
Channel deposition increases flood risk
BenefitThreat
EXPLANATION
U.S. Department of the InteriorU.S. Geological Survey
Fact Sheet 2011–3083August 2011
Sediment Load from Major Rivers into Puget Sound and its Adjacent WatersJonathan A. Czuba, Christopher S. Magirl, Christiana R. Czuba, Eric E. Grossman, Christopher A. Curran, Andrew S. Gendaszek, and Richard S. Dinicola
Printed on recycled paper
Highlights
• Eachyear,anestimatedloadof6.5milliontonsofsedi-mentistransportedbyriverstoPugetSoundanditsadjacentwaters—enoughtocoverafootballfieldtotheheightofsixSpaceNeedles.
• Thisestimatedloadishighlyuncertainbecausesedimentstudiesandavailablesediment-loaddataaresparseandhistoricallylimitedtospecificrivers,shorttimeframes,andanarrowrangeofhydrologicconditions.
• Thelargestsedimentloadsarecarriedbyriverswithglaci-atedvolcanoesintheirheadwaters.
• Researchsuggests70percentofthesedimentloaddeliveredtoPugetSoundisfromriversand30percentisfromshorelineerosion,butthemagnitudeofspecificcontributionsishighlyuncertain.
• Mostofariver’ssedimentloadoccursduringfloods.
Why is River Sediment Important to Puget Sound?
RiverscarryfreshwaterintoPugetSoundaswellassedimentandothermaterials,suchaswood,importanttoestuarineandnearshorehabitat,aquaticecology,andwaterquality.Historicalchannelizationofriversanddeltashasalteredsediment-transportpathwaysbyrestrictingsedimentdeliverytofloodplainsandredirectingsedimentoffshore.Paradoxically,sedimentisbothabenefitandathreattoecosystemsandsociety(fig. 1).Sufficient,butnotexcessive,amountsofsedimentareimportantresourcesforbeaches,deltas,andothercoastalhabitatsthatsustainecosystems,vegetation,andanimalsthatpeopledependon.Excessiveamountsofsedimentcanplacestressonavarietyofspeciesandhabitats.Forexample,eelgrassmeadows,whichprovideimportant
nearshoremarinehabitatforfish,shellfish,andinvertebrates,aswellasfoodforwaterfowlanddetritusfeeders,canbeburiedorfragmentedbyincreasedsedimentdeliveryassociatedwithriver-deltachannelization,likethoseoffshoreoftheSkagitRiver(Grossmanandothers,2011).Incontrast,whensedimentdeliveryisdepleted,nearshorecriticalhabitatandbeachescanbeerodedbynaturalcoastalprocessesandlost(Warrickandothers,2009).Changesinsedimentgrain-sizecompositionalsoaffectecosystems.Forexample,manyshellfishbedsandforage-fishspawningbeachesdependonaspecificsedimentgrain-sizecompositionthatislinkedtoland-useactivitiesandhydrologicconditionsthatreleaseandcarrysedimenttoPugetSound(Gelfenbaumandothers,2009).Waterquality,nearshoreandoffshorehabitats,andaquatic-ecosystemhealthareaffectedbycontaminantsandnutrientsthatpreferentiallyadsorbtofinesedimentsandaredeliveredtoPugetSound.Oncepresent,thesecontaminantscanbioaccumulateinfishandshellfishmakingtheseseafoodstoxicforhumanconsumption.
What is Sediment Load?
Ariver’ssedimentloadiscomputedfromwaterdischargeandsediment-concentrationdata,andrepresentsthefluxofsedimenttransportedbytheriver;itisusuallyexpressedasmasspertime,forexample,tonsperyear(tons/yr).Mostofariver’ssedimentloadoccursduringfloods.Sedimentiseithertransportedwithintheflowassuspendedloadortransportedalongtheriverbedbyrolling,sliding,orsaltating(hopping)asbedload.Asuspended-sedimentsampler,consistingofanozzleconnectedtoacontainerthatsamplesaflowingriver,isusedtomeasuretheconcentrationofsedimentinthewatercolumn.Similarly,abedloadsamplerplacedonthebottomofaflowingrivercollectsthecoarse-grainedsedimentmovingalongtheriverbed.Thesumofthemeasuredsuspendedloadandbedloadisthetotalload.Typically,bedloadrepresentsabout5–20percentofthetotalloadcarriedbyariver.MostreportedsedimentloadsforPugetSoundriversonlyincludethesuspendedloadandthusreflectaminimumestimateofthetotalsedimentload.
Figure 2. Mean annual discharge of major rivers draining into Puget Sound. The size of the arrow is scaled to the mean annual discharge. Data from Williams (1981).
124° 123° 122° 121°
49°
48°
47°
0 25 50 75 MILES
0 25 50 75 KILOMETERS
Strait of Georgia
Seattle
Tacoma
Bremerton
Olympia
Everett
Mt Vernon
Bellingham
Puget Sound
Mt. Baker
Glacier Peak
Mt. Rainier
Olympic Mountains
Casc
ade
Rang
e
Puget Lowland
British Columbia CANADA
Washington UNITED STATES
Strait of Georgia
Seattle
Tacoma
Bremerton
Olympia
Everett
Mt Vernon
Bellingham
British Columbia CANADA
Washington UNITED STATES
Puget Sound
Mt. Baker
Glacier Peak
Mt. Rainier
Olympic Mountains
Casc
ade
Rang
e
Puget Lowland
Salish Sea
PacificOcean
Strait of Juan de Fuca
DungenessRiver
ElwhaRiver
Hamma Hamma RiverDuckabush River
Dosewallips River
Big Quilcene River
Deschutes River
Nooksa
ck Rive
r
Nooksa
ck Rive
r
Samish RiverSamish River
Skagit RiverSkagit River
Stillaguamish RiverStillaguamish River
Snohomish RiverSnohomish River
Lake WashingtonShip CanalLake WashingtonShip Canal
Duwamish River
Duwamish RiverPuyallup River
Puyallup RiverNisqually River
Nisqually River
Deschutes River
All other
tribu
taries
All other
tribu
taries
Skokomish RiverSkokomish River
Hamma Hamma RiverDuckabush River
Dosewallips River
Big Quilcene River
DungenessRiver
ElwhaRiver
Fraser River
3,200
3,600
190
2,700
1,400
400 2,100
570670
180
4602,000
500
1,3001,400
3,130
3,200
18,000
10,000
3,600
190
2,700
1,400
400 2,100
570670
180
4602,000
500
1,3001,400
3,100
EXPLANATIONDrainage-basin boundary
Subbasin boundary
Mean annual discharge, in cubic feet per second
190
Factors Affecting Sediment Delivery to Puget SoundAnumberofgeologicandgeomorphicfactorsaffect
sedimentsupplytoPugetSound.Watershedgeology,slope,landuse,precipitation,mountainupliftrates,volcanism,glaciers,lahars,andweatheringallaffectthesedimentloadcarriedbytheregion’srivers.Riversdrainingglaciatedterrainarenotoriouslyladenwithlargeamountsofsediment.Landuse,includingagricultural,forested,andurbanareas,affectsthesedimentload,aswellasnutrientsandtoxics,carriedbyrivers.DamswithinabasinstoresedimentthatultimatelyreducessedimentdeliverytoPugetSoundanditsadjacentwaters.However,removaloflargedams,likeintheplannedElwhaRiverdam-removalprojectbeginningin2011,canresultinlarge,short-termreleasesofsedimentdownstreamandanewlyadjustedannualsedimentloadinthelongterm.
Climatechangeandshiftinglandusethreatentoaltersedimentloadsinrivers.Anincreasedsedimentloadmaybeimportantinmaintainingestuarineandnearshorehabitatsassealevelrisesinresponsetoclimatechangebyenablingmarshesandcoastlinestoaccumulatesedimentandbuildtopography.ClimatepatternshiftsalsowillalterthetimingandmagnitudeoffloodsthatcarrysedimenttoPugetSound.
Sediment Transported by Rivers into Puget SoundEachyear,about12trilliongallons(totalmeanannual
dischargeofabout52,000cubicfeetpersecond[ft3/s])offreshwaterflowintoPugetSoundanditsadjacentwatersfromtheregion’sriversandstreams(fig. 2,table 1).Theserivers,
inturn,carryanestimated6.5milliontons(1ton=2,000pounds)ofsedimentintoPugetSoundanditsadjacentwaters(fig. 3,table 1).Thissedimentisderivedfromtheweatheringanderosionofbedrockandsoilinbasinswhererunofffromrainandsnowcarriesparticlesintomain-stemriversthattransportthematerialdownstreamtoPugetSound.Thequantityandsizeofsedimentmovedbyriversdependsondischargeandriverslope,andalthoughevensmallstreamscarrysiltsandclays,onlythesteepestriverstransportgravels,cobbles,andboulders.Mountainousriversreadilytransportgravelsandcobbles,anddepositthissedimentdirectlyintoPugetSoundwheretheseriversdraindirectlyintotheSound,suchastheElwhaandDungenessRivers.AsmountainousriversenterPugetLowland,thecoarseparticles(gravel,cobbles,andboulders)tendtodepositonriverbeds,suchasinthePuyallupRiver.Thiscoarse-sedimentdepositionreducestheriver’scapacitytoconveyafloodwithoutovertoppingitsbanksandincreasesthefloodhazard,necessitatingrivermanagementtoreducefloodrisktonearbypeopleandinfrastructure(Czubaandothers,2010).Fineparticles(clay,silt,andsand),however,continuetobecarrieddownstream,outofthePugetLowland,andintoPugetSound.SedimentdeliveredintoPugetSoundisredistributedbycomplexinteractionsoftidalandwind-drivencurrentsthroughoutthebaysandinlets.
Available Sediment-Load StudiesOnlyahandfulofwater-qualityandsediment-transport
studieshavebeenconductedtoquantifysedimentloadingfromriversintoPugetSound,andthemajorityofthesestudieswerelimitedtospecificriversusingsedimentdatacollectedduringonlyafewyearsinthe1960sand1970s(table 1).Insomecases,thesediment-loadestimateswerebasedonlimitedmeasurementsaddingsignificantuncertaintybecausesedimentloadinariverisvariable,changingbyasmuchasanorderofmagnitudebetweenyearsorbetweenstorms(forexample,Nelson,1979).Inaddition,themeasurementsmaynothave
Modern Sediment-Surrogate Monitoring Technologies
Recentadvancesinhydroacousticandopticaltechnologieshavefosteredrenewedinterestinmonitoringandtrackingsedimentloadsinrivers(GrayandGartner,2009).Couplingthesetechnologieswithstrategicsedimentsamplingenablesthenear-continuousmeasurementandreportingofsedimentloadinriversatafractionofthecostoftraditionalsediment-measurementtechniquesappliedduringthe20thcentury.Inadditiontoreportingthesedimentloadinagivenriver,theseinstrumentsalsohavethecapabilitytoestimateparticle-sizedistributionofsedimentdeliveredbyrivers.
Figure 3. Annual sediment load of major rivers draining into Puget Sound measured at or near the river mouth. The size of the arrow is scaled to the annual sediment load. Data sources listed in table 1.
124° 121°
49°
47°
0 25 50 75 MILES
0 25 50 75 KILOMETERS
Strait of Georgia
Seattle
Tacoma
Bremerton
Olympia
Everett
Mt Vernon
Bellingham
Puget Sound
Mt. Baker
Glacier Peak
Mt. Rainier
Olympic Mountains
Casc
ade
Rang
e
Puget Lowland
British Columbia CANADA
Washington UNITED STATES
Strait of Georgia
Seattle
Tacoma
Bremerton
Olympia
Everett
Mt Vernon
Bellingham
British Columbia CANADA
Washington UNITED STATES
Puget Sound
Mt. Baker
Glacier Peak
Mt. Rainier
Olympic Mountains
Casc
ade
Rang
e
Puget Lowland
Salish Sea
PacificOcean
Strait of Juan de Fuca
DungenessRiver
ElwhaRiver
Hamma Hamma RiverDuckabush River
Dosewallips River
Big Quilcene River
Deschutes River
Nooksa
ck Rive
r
Nooksa
ck Rive
r
Samish RiverSamish River
Skagit RiverSkagit River
Stillaguamish RiverStillaguamish River
Snohomish RiverSnohomish River
Lake WashingtonShip CanalLake WashingtonShip Canal
Duwamish River
Duwamish RiverPuyallup River
Puyallup River
Nisqually River
Nisqually River
Deschutes River
All other
tribu
taries
All other
tribu
taries
Skokomish RiverSkokomish River
Hamma Hamma RiverDuckabush River
Dosewallips River
Big Quilcene River
DungenessRiver
ElwhaRiver
Fraser River
??
1211
30
6
12035
1,400
2,800
1818
3.33.3
120
?? 980
490
??
35
410
1211
30
6
??
210210
EXPLANATIONDrainage-basin boundarySubbasin boundaryAnnual sediment load, in thousands of tonsPublished load estimates could not be found or do not exist
3.3
123° 122°
48°
?
includedanaccuraterepresentationoffloodswhenthegreatestsedimentconcentrationsoccur,whichwouldleadtounderestimatesoftheannualsedimentload.Thesediment-loadestimates(table 1)wereobtainedfromreadilyavailablestudiesbyfederalandstateagencies,consultants,andacademicresearchers.Onlythosestudieswheretotal-orsuspended-loadestimatesweredeterminednearthemouthoftherespectiveriverasitenteredPugetSoundwereincludedintable 1andfigure 3.Thesesediment-loadestimateswereconvertedintotonsperyearasnecessaryandwereaveragedtogetherwhenmultiplestudiesprovideddifferentestimates.Themostreliablesediment-loadestimatesincludedsedimentdataspanningmanyyears(forexample,theloadestimatesfromtheSkagitandDeschutesRivers;table 1).TheDeschutesRiversediment-loadestimateisuniquebecauseitisbasedonrepeatsurveysofthedeltavolumeinadditiontodirectmeasurementsofsedimentloadintheriver.Allothersediment-loadestimatesfromriversdrainingtoPugetSoundwereofsuspendedloadonlyanddonotaccountforbedload.Theestimatesbasedondatacollectedforafewyearsmayormaynotrepresenttheriver’slong-termaveragesedimentload.
Sediment-Load Estimates for Puget Sound Rivers
Thelargestsedimentloadsarenotnecessarilythosecarriedbytherivershavingthelargestmeanannualdischarge.Instead,thethreeriverscarryingthelargestsedimentloads,theSkagit,Nooksack,andPuyallupRivers,allcontainglaciatedvolcanoesintheirheadwaters(fig. 3).TheSkagitRiverdrainsbothMountBakerandGlacierPeak,althoughmuchofthesedimentloadderivedfromMountBakerisretainedinmanmadereservoirs.TheNooksackRiverdrainsthenorthernsectionsofMountBakerandthePuyallupRiverdrainsthenorthernandwesternsectionsofMountRainier.
TheothermajorsourceofsedimenttoPugetSoundisfromshorelineerosion,whichcontributessedimentofallgrainsizes,includingclay,silt,sand,gravel,cobbles,andboulders,toareasawayfromriverdeltas.Dexterandothers(1981)estimatedshorelineerosioncontributesabout2.6milliontonsofsedimentperyeartoPugetSound;however,theuncertaintyinthisestimateislarge.Thecombinedsedimentloadfromriversandshorelineerosionisabout9.1milliontonsperyear,about70percentisfromriversand30percentisfromshorelineerosion.
WhilenotdrainingdirectlyintoPugetSound,theFraserRiverinBritishColumbiadrainsintotheStraitofGeorgiaandisaprodigiouscontributoroffreshwaterandsedimentintothegreaterSalishSea(table 1).TheFraserRivercarriesatotalloadofabout20milliontonsofsedimentperyearintotheStraitofGeorgia(ChurchandKrishnappan,1998).
Opportunities for Monitoring and Basic ResearchThesediment-loadestimatesforriversdrainingtoPuget
Soundmaybeinaccuratebyanorderofmagnitude(table 1)
becauseofthesparseavailabilityofreliablesedimentdataandthevariablenatureofsedimenttransport.Theproblemisfurtherexacerbatedbytheout-of-datestatusofmanydatasetsassignificantchangesinlanduse,urbanization,andclimateinthe21stcenturylikelyhavemodifiedsedimentsourcesandtransportsincethe1970s,whenmostoftheregion’ssedimentdatawerecollected.Recentstrategicsamplingofsedimentduringtheentirerangeoflow-andhigh-flowconditions,aswellasdifferentseasons,hasgreatlyimprovedtheabilitytoquantifyandreduceuncertaintyofsediment-deliveryestimatesbytheSkagitRiver(Curranandothers,2011).Giventheimportantaffectofsediment,asabenefitandathreat,toPugetSoundecosystems,detailedmonitoringandanalyticalunderstandingofsedimentload,size,quality,andmovementareneededtobestunderstand,protect,andrestoreimportantecosystemprocessesandfunctionsinPugetSound.
For more information contact:
Director, Washington Water Science CenterU.S. Geological Survey, 934 Broadway, Suite 300Tacoma, Washington 98402http://wa.water.usgs.gov
References Cited
CapitolLakeAdaptiveManagementPlan1999to2001,1999:ThurstonRegionalPlanningCouncil,103p.
Church,M.,andKrishnappan,B.G.,1998,Sedimentsources,transportprocesses,andmodelingapproachesfortheFraserRiverinC.GrayandT.Tuominen,eds.,HealthoftheFraserRiverAquaticEcosystem:EnvironmentCanada,DOEFRAP1998–11,18p.
Curran,C.A.,Grossman,E.E.,Mastin,M.C.,andHuffman,R.L.,(inpress),SedimentloadanddistributioninthelowerSkagitRiver,SkagitCounty,Washington,USA.ForsubmissiontoContinentalShelfResearch.
Czuba,J.A.,Czuba,C.R.,Magirl,C.S.,andVoss,F.D.,2010,Channel-conveyancecapacity,channelchange,andsedimenttransportinthelowerPuyallup,White,andCarbonRivers,westernWashington:U.S.GeologicalSurveyScientificInvestigationsReport2010–5240,104p.
Dexter,R.N.,Anderson,D.E.,Quinlan,E.A.,Goldstein,L.S.,Strickland,R.M.,Pavlou,S.P.,Clayton,J.R.,Kocan,R.M.,andLandolt,M.,1981,AsummaryofknowledgeofPugetSoundrelatedtochemicalcontaminants:NationalOceanicandAtmosphericAdministrationTechnicalMemorandumOMPA-13,435p.
Downing,J.,1983,ThecoastofPugetSound:itsprocessesanddevelopment.UniversityofWashingtonPress,Seattle,Wash.,126p.
Embrey,S.S.,andFrans,L.M.,2003,Surface-waterqualityoftheSkokomish,Nooksack,andGreen-DuwamishRiversandThorntonCreek,PugetSoundbasin,Washington,1995–98:U.S.GeologicalSurveyWater-ResourcesInvestigationsReport02–4190,192p.
Gelfenbaum,G.,Fuentes,T.L.,Duda,J.J.,Grossman,E.E.,andTakesue,R.K.,eds.,2009,ExtendedabstractsfromtheCoastalHabitatsinPugetSound(CHIPS)2006Workshop,PortTownsend,Washington,November14–16,2006:U.S.GeologicalSurveyOpen-FileReport2009–1218,136p.
Gray,J.R.,andGartner,J.W.,2009,Technologicaladvancesinsuspended-sedimentsurrogatemonitoring:WaterResourcesResearch,v.45,20p.
Grossman,E.E.,George,D.A.,andLam,A.,2011,ShallowstratigraphyoftheSkagitRiverDelta,Washington,USAderivedfromsedimentcores:U.S.GeologicalSurveyOpen-FileReport2011–1194.
Nelson,L.M.,1971,SedimenttransportbystreamsintheSnohomishRiverbasins,Washington:October1967–June1969:U.S.GeologicalSurveyOpen-FileReport71–215,96p.
Nelson,L.M.,1974,SedimenttransportbystreamsintheDeschutesandNisquallyRiverbasins,Washington:November1971–June1973:U.S.GeologicalSurveyOpen-FileReport74–1078,33p.
Nelson,L.M.,1979,SedimenttransportbytheWhiteRiverintoMudMountainReservoir,Washington,June1974–June1976:USGSWater-ResourcesInvestigationsReport78–133,26p.
Paulson,A.J.,Feely,R.A.,CurlJr.,H.C.,Crecelius,E.A.,andRomberg,G.P.,1988,SourcesandsinksofPb,Cu,Zn,andMninthemainbasinofPugetSound:NationalOceanicandAtmosphericAdministrationTechnicalMemorandumERLPMEL-77,26p.
Santos,J.F.,andStoner,J.D.,1972,Physical,chemical,andbiologicalaspectsoftheDuwamishRiverEstuaryKingCounty,Washington1963–67:U.S.GeologicalSurveyWater-SupplyPaper1873–C.,74p.
Warrick,J.A.,George,D.A.,Gelfenbaum,G.,Ruggiero,P.,Kaminsky,G.M.,andBeirne,M.,2009,Beachmorphologyandchangealongthemixedgrain-sizedeltaofthedammedElwhaRiver,Washington:Geomorphology,v.111,p.136–148.
Williams,J.R.,1981,Principalsurface-waterinflowtoPugetSound,Washington:U.S.GeologicalSurveyWater-ResourcesInvestigationsReport84–4090,6sheets.
Wise,D.R.,RinellaIII,F.A.,Rinella,J.F.,Fuhrer,G.J.,Embrey,S.S.,Clark,G.E.,Schwarz,G.E.,andSobieszczyk,S.,2007,Nutrientandsuspended-sedimenttransportandtrendsintheColumbiaRiverandPugetSoundbasins,1993–2003:U.S.GeologicalSurveyScientificInvestigationsReport2007–5186,117p.
Table 1. Puget Sound sediment-load data.
[MeanannualdischargedatafromWilliams(1981).mi2,squaremile;ft3/s,cubicfeetpersecond;tons/yr,tonsperyear;Annualsedimentload:n.e.,publishedloadestimatescouldnotbefoundordonotexist;--,nodata]
Basin (area mi2)
Mea
n an
nual
di
scha
rge
(ft3 /s
)
Ann
ual s
edi-
men
t loa
d (to
ns/y
r)
Tim
e pe
riod
w
hen
sed-
imen
t-lo
ad
data
wer
e co
llect
ed
Skagit(3,200)1 18,000 2,800,000 1974–93,2006–09
Snohomish(1,800)2,3,4 10,000 490,000 1964–66,1967–68,2000
Puyallup(980)2,4 3,600 980,000 1964–66,2000Nooksack(840)2,4,5 3,200 1,400,000 1964–66,
1996–98,2000Nisqually(770)2,6 2,100 120,000 1964–66,
1971–72Stillaguamish(700)2 2,700 18,000 1964–66LakeWashingtonShipCanal(600)7
1,400 3,300 1981–82
Duwamish(500)4,5,8 1,400 210,000 1964–66,1996–98,2000
Elwha(320) 2,000 n.e. --Skokomish(250)2,4,5 1,300 410,000 1964–66,
1996–98,2000Dungeness(200) 460 n.e.Deschutes(170)9 400 35,000 1952–98Samish(120) 190 n.e. --Dosewallips(120)2 670 30,000 1964–66HammaHamma(80)2 500 12,000 1964–66Duckabush(80)2,4 570 11,000 1964–66,2000BigQuilcene(70)2 180 6,000 1964–66Allothertributaries(2,300) 3,100 n.e. --TotalPugetSound(13,000) 52,000 6,500,000 --Fraser(85,000)10 130,000 20,000,000 1965–96
1Curranandothers,2011. 6Nelson,1974.2Downing,1983. 7Paulsonandothers,1988.3Nelson,1971. 8SantosandStoner,1972.4Wiseandothers,2007. 9CapitolLakeAdaptiveManagementPlan,1999.5EmbreyandFrans,2003. 10ChurchandKrishnappan,1998.
