Process-based Restora.on of Deposi.onal Stream Reaches– A Paradigm Shi; to Stage 0

JohanHogervorstForestHydrologistWillame5eNa7onalForest

DeerCreek,McKenzieWatershed,Willame5eNa7onalForest

FivemileCreek,CoastalLakesWatershed,SiuslawNa7onalForest

•  HistoricalCondi7ons

•  DisturbanceHistory

•  Evolu7onofRestora7oninthePacificNorthwest(par7cularlyOregon)

•  ParadigmShiNtoStage0projects

HistoricFloodplainCondi0oninDeposi0onalEnvironments•  Vegeta7ondiversity•  Eleva7onaldiversity•  Mul7pleflowpaths•  Bothdownedwoodandfuturewoodsupply•  Highwatertable•  Beaverdams•  FrequentfloodplainweUng•  Maximumpatchcomplexity

CluerandThorne,2013–“STAGE0”oftheStreamEvolu7onModel

FlowRegime

SedimentRegime

Channelfeatures

Floodplain

•  Routingandstreamflow•  Floodstorage

•  Sedimentretentionandstorage•  Sedimenttransport•  Floodplainbuilding

•  Primaryproduction•  SecondaryProduction•  Feeding/predation

•  Shading•  Rootreinforcementofbanks•  Woodsupply•  Litterfall•  Lateseasonwaterstorage(added)•  Transportandstorageofseedsandplantpropagules

•  Poolandbarformation•  Channelmovement

Biology

* Stream and Watershed Restoration: A Guide to Restoring Riverine Processes and Habitats Copyright © 2013 John Wiley & Sons, Ltd

ChangedCondi0oninDeposi0onalEnvironments

ChangedCondi0oninDeposi0onalEnvironments•  Roadbuilding

ChangedCondi0oninDeposi0onalEnvironments•  Roadbuilding•  Coniferharvest

ChangedCondi0oninDeposi0onalEnvironments•  Roadbuilding•  Coniferharvest•  Dikingandchanneliza7on

        

   

ChangedCondi0oninDeposi0onalEnvironments•  Roadbuilding•  Coniferharvest•  Dikingandchanneliza7on•  Blockingorfillingsidechannels

        

   

ChangedCondi0oninDeposi0onalEnvironments•  Roadbuilding•  Coniferharvest•  Dikingandchanneliza7on•  Blockingorfillingsidechannels•  Grazingandfarming

ChangedCondi0oninDeposi0onalEnvironments•  Roadbuilding•  Coniferharvest•  Dikingandchanneliza7on•  Blockingorfillingsidechannels•  Grazingandfarming

Leadsto:•  Singleincisedchannel•  Lossofwatertable/wetlands•  Alteredvegeta7ontypes•  Minimallargewood•  AlteredStreamPower–>changefromdeposi0ontotransport

Watertable

StreamEvolu7onModel,Stages2-4CluerandThorne,2013

StreamPowerPerUnitWidth-Low•  Flowdistributedthroughoutaroughenedsurface

HistoricFloodplainCondi0oninDeposi0onalEnvironments

ChangedCondi0onfromDeposi0onaltoTransportEnvironments

StreamPowerPerUnitWidth-High“firehoseeffect”

FlowRegime

SedimentRegime

Channelfeatures

Floodplain

•  Routingandstreamflow•  Floodstorage

•  Sedimentretentionandstorage•  Sedimenttransport•  Floodplainbuilding

•  Primaryproduction•  SecondaryProduction•  Feeding/predation

•  Shading•  Rootreinforcementofbanks•  Woodsupply•  Litterfall•  Lateseasonwaterstorage(added)•  Transportandstorageofseedsandplantpropagules

•  Poolandbarformation•  Channelmovement

BiologyCriticaltoNativeAqu

aticSpe

cies

Channel-centric,form-basedrestora0on(1980stopresent)Advantages:•  Easytocount#ofstructures,poolscreatedandmilestreated•  Focusedtreatmentthat’srela7velyinexpensivepersite

Disadvantages:•  Processandfunc7onminimallyaddressed•  Blowsoutinbigstorms•  Unnaturalmaterialsandengineeringinstream•  Streampowerandwatertablenotaddressed

Restora0onSolu0ons

StreamPowerPerUnitWidth-High•  Form-basedrestora7onworkingagainsta“firehose”

Stage0-ValleyboPom,process-basedrestora0on(2005topresent)

Advantages:•  Processandfunc7onfullyaddressedforen7refloodplain•  Watertablerestored•  Templatecreatedforna7vevegeta7onrecovery•  Patchcomplexitymaximizedwithdynamicchangean7cipatedover7me•  Largestormswelcome(streamenergyaddressed)

Disadvantages:•  Highlevelofdisturbanceini7ally–turbidityduringconstruc7on•  Toughtomonitorwithtradi7onalsurveys•  Socialacceptanceforanewtechnique

Restora0onSolu0ons

StreamPowerPerUnitWidth-ReturntoLow

Floodplains are good!