Interim CONSTRUCTION REPORT Gordon’s Brook Wetlands …...of Shallow Marsh (0 – 0.4 m depth), as...

InterimCONSTRUCTIONREPORT

Gordon’sBrookWetlandsPhaseIIIinAldergroveRegionalPark

Submittedto:

MetroVancouverRegionalParksEnvironmentandClimateChangeCanada

HabitatConservationTrustFundFraserValleyConservancy

BCMinistryofForests,LandsandNaturalResourceOperations

March31,2018

Submittedby:

BALANCEECOLOGICALVancouverBC

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This project was undertaken with the financial support of:Ce projet a été réalisé avec l’appui financier de :

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SUMMARY

The goals of this project are, through the restoration of a swampwetland on historic agriculturalfields,to:

a) ProviderecoveryhabitatfortheendangeredOregonSpottedFrog;

b) Enhancegeneralwildlifebiodiversity,withaparticularfocusonSpeciesatRisk;

c) Provide outdoor education, stewardship and research opportunities inwetland restorationandspeciesrecovery;and

d) Increaseourknowledgeofmarshrestorationtechniques.

Constructioninvolvedthecontrolofinvasiveplantspecies;thehydrologicrestorationofthehistoricwetland by decommissioning constructed drainage features; re-sculpting topography to increasewetted area; and re-plantingwith native vegetation. The constructedmarsh includes features thatpromoteusebyspecies-at-risk.Inadditiontoprovidinghabitatfornativespecies,theprojecthasandwillcontinuetoprovidestewardship,research,andeducationalopportunitiesforthegeneralpublic,elementaryschools,highschools,collegesanduniversitiesintheLowerMainlandofBritishColumbia.

In2017wemoved3.4haofsoil,andaffectedanadditional1.6hawiththerecoveredhydrology.Thisincludes0.07HaofDeepPool(>1mdepth),0.73HaofShallowWater(0.4–1mdepth),and1.06Haof ShallowMarsh (0–0.4mdepth), aswell asup to2.94Haof Floodplainhabitat and0.21HaofUplandhabitat.Intotal,6,535nativetrees,shrubsandaquaticplantswereaddedtoPhasesIIandIIIaffecting4,079m2(0.41Hectares),including3,104m2ofnewriparianandaquatichabitatinPhaseIII,104m2newand871m2ofinfilledriparianandaquatichabitatatPhaseII.

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TABLEOFCONTENTS

1 BACKGROUND...........................................................................................................................12 PERSONNEL,CONSTRUCTIONTIMELINEANDWORKZONES.......................................................23 PRE-EXISTINGCONDITIONS.......................................................................................................44 SITEPREPARATION....................................................................................................................4

4.1 HYDROLOGICALPREPARATION:JUNE2017.........................................................................................44.2 CONTROLOFINVASIVESPECIES:2015-2017.....................................................................................6

5 CONSTRUCTION:JULY2017.......................................................................................................75.1 TRENCH/DRAINTILEDECOMMISSIONING..........................................................................................75.2 CONSTRUCTION..............................................................................................................................8

6 REVEGETATIONWITHNATIVEPLANTSPECIES:OCTOBER2016.................................................147 ANTICIPATEDOUTCOMESANDNEXTSTEPS..............................................................................18

7.1 HYDROLOGY.................................................................................................................................187.2 INVASIVESPECIES..........................................................................................................................197.3 REVEGETATION.............................................................................................................................197.4 MONITORINGANDADAPTIVEMANAGEMENT....................................................................................197.5 EXPANSION..................................................................................................................................20

8 PUBLICENGAGEMENT..............................................................................................................21

ConstructionReport–Gordon’sBrookPhaseIII BALANCEECOLOGICALLTD. PAGE1OF27

1 BackgroundTheFraserValleyConservancy(FVC),inpartnershipwithMetroVancouverParks(MV)andtheBCMinistry of Forests, Lands, Natural Resource Operations and Rural Development (FLNR)implemented Phase III of a three-phase restoration project returning historic agricultural landsinto wetlands. This interim construction report addresses works conducted in 2017 regardingPhase III: the restorationof shallowmarsh andponds inAldergroveRegional Park in the FraserValley of British Columbia (Figure 1). The constructed wetland is comprised of shallow marsh,channelsandpondsthatweredugbetweenstandsofrecoveringwillow,cottonwoodandalder.

Funding for this restorationprojectwasprovidedbyEnvironmentandClimateChangeCanada’sNational Wetland Conservation Fund (NWCF) and the Habitat Conservation Trust Fund (HCTF),withcontributionsfromMV,FVC,FLNRandothers.

Thegoalsofthisprojectwere,throughtherestorationofashallowmarshandassociatedpondsonhistoricagriculturalfields,to:

a) ProviderecoveryhabitatfortheendangeredOregonSpottedFrog;b) Enhancegeneralwildlifebiodiversity,withaparticularfocusonSpecies-at-Risk;c) Provideoutdooreducation,stewardshipandresearchopportunitiesinwetlandrestoration

andspeciesrecovery;andd) Increaseourknowledgeofmarshrestorationtechniques.

Figure1.LocationofGordon'sBrookWetlandPhasesItoIIIinAldergroveRegionalPark,Aldergrove,BritishColumbia.


2 Personnel,ConstructionTimelineandWorkZonesWorkwas directed byMonica Pearson, initially contracted to the Fraser Valley Conservancy asBalanceEcologicaluntilshetookapositionasSr.AquaticEcosystemsBiologistatBCFLNRinJune2017.Monica continued toworkon theproject,with hours contributedby theProvinceduringregular work hours with additional hours and expenses billed to the project via FVC. Thisarrangementwasapprovedbyhermanagersandshewillcontinuetobeavailabletotheproject.ContractorsandpersonnelarelistedinTable1.

Table1.ContractorsandPersonnelTask Company PersonnelProjectManagement BalanceEcologicalLtd.(BEL)/

BCFLNRFishandAquaticWildlifeMonicaMPearson,R.P.Bio

Blackberryremoval GeorgeFlathConstruction(GFC) MarvinWheelerEquipmentOperator(Construction)

RoberdsExcavation(RE) JimRoberds

Labour FraserValleyConservancy(FVC) WinterMoon/NatashaWilbrink/AleeshaSwitzer

Planting FraserValleyWatershedsCoalition(FVWC)

NatashaCoxlead

Planning,DesignandImplementationphasesofthisprojectspannedfromNovember2014toMay2017. Concept planning began in November 2014. Pre-construction site assessments, biologicalandhydrologicalmonitoring,designproposalsandpermittingwereconductedinpartnershipwiththe landowner, Metro Vancouver, from May 2015 to June 2017. Site preparation, hydrologicrestoration and revegetation activities spanned from June 2015 andwill continue until October2018 (Table 2). Invasive species control began in January 2015 and continued throughoutconstruction. Earth-moving works occurred in July of 2017 to take advantage of dry summermonths. Planting occurred in autumn to allow shrubs and trees to establish roots through thewinterandspring.

Table2.TimelineofhabitatconstructionactivitiesatGordon’sBrookMarshPhaseIII.

Dates Task Zone Equipment Personnel

Site Preparation

June

20

15 22 Reed canarygrass (RCG)

treatment - mowing GB III Rosegate Crop

Services Matt DeJong

Oct

20

15 17 RCG treatment – Glyphosate GBIII Rosegate Crop


Jan

2016

2 – 6 Blackberry removal – manual and mechanical.

GBIII North-east Manual Hitachi 150 with thumb

GFC

Aug

20

16 5 RCG treatment – Glyphosate GBIII Rosegate Crop



June

20

17

6-7 Pre-construction beaver dam / drainage management

0 Ave ditch / Gordon’s Brook

Hand tools FVC

30 RCG treatment – Glyphosate Transorb HC formulation

GBIII Rosegate Crop Services

Matt DeJong

Dates Task Zone Equipment Personnel

Hydrologic restoration

July

201

7

3 - 4 Lay out design, move in machinery, safety briefings. Trench south of field to identify drain tile locations and direction exiting to 0 Ave ditch. Record locations and back-fill trench.

GBIII John Deere 200CLC

RE, FLNR, BEL, FVC

5 - 8 Excavate and bulldoze topsoil down to mineral soil, cut and fill drain tile. Rough in ponds and spoil / berms. Install large woody debris.

South-west marsh and ponds.

JD 200CLC John Deere Crawler Dozer 650G Komatsu CD60

RE, FLNR, BEL, FVC

10 - 13

Excavate and bulldoze topsoil down to mineral soil, cut and fill drain tile. Rough in ponds and spoil / berms. Install large woody debris.

South-east marsh and ponds

JD 200CLC JD Crawler Dozer 650G Komatsu CD60

RE, FLNR, BEL, FVC

14 - 17 Excavate and bulldoze topsoil down to mineral soil, cut and fill drain tile. Rough in ponds and spoil / berms. Install large woody debris.

North-west marsh and ponds / north connector channels

JD 200CLC JD Crawler Dozer 650G Komatsu CD60

RE, FLNR, BEL, FVC

18 - 19 Phase II – Improve access road for blackberry cleanup / construct willow farm

Phase II – Road / Willow farm

JD 200CLC JD Crawler Dozer 650G

RE, FLNR, BEL, FVC

21 - 22 Clean up, tidy site, final touches.

Marsh: North-west

JD 200CLC

RE, FLNR, BEL, FVC

Revegetation

Aug

20

17 20 - 30 As-built mapping, planting

design development GBIII FVC, FLNR

Oct

201

7 3 – 6 Plant layout, planting, volunteer group planting, herbivory guard installation; willow harvest and planting. Willow farm installation.

GBIII South-west Marsh GBII Willow farm

Hand tools FVWC, FVC, FLNR

Mar

ch

2018

26 – 29 Infill GBII willow farm and swamp; GBII to accommodate year-end budget restrictions and flooding in GBIII.

GBII Willow Farm and Swamp infill

Hand tools FVC, FVWC

[Oct

20

18] TO COME – Additional planting

in GBIII and major outreach event. Additional funding confirmed.

GBIII Hand tools FVC, FVWC


3 Pre-existingconditionsPhaseIIIencompassesa6.4Hafielddirectlynorthof0AveattheeasternedgeoftheTownshipofLangley.Thefieldisborderedtotheeastandwestbydrivewaystothehistoricfarmhousesthatnow belong to Metro Vancouver’s Regional Parks, and to the north by a steep hillslope withrecoveringmixedconiferousanddeciduous forests,horsepastures, andhay fields.Detailed sitehistory and a discussion of soil and hydrological investigations can be found in the RestorationPlan.Thetopography,soilsandhydrologyofPhaseIIIconfirmthatahistoricmarshwasconvertedtoagriculturalfields.

Thefieldslopesfromthenorth-easttothesouth-westanddrainsintotwoditches:onethatrunsnorth-southalongthewesterndrivewayandthesecond,mainditchalongthenorthsideof0Ave.Themainditchdrainswest intoPepinBrookthencrosses0Avedrainingsouth intoWashingtonState. The 0 Ave ditch is rarely cleaned and regularly plugged by beavers (Castor canadensis),causing water to back-up into the field. These back-ups impacted our ability to implement acompleteherbicideregime,andthreatenedtopreventworksaltogetherin2017.Historicimageryindicated thathydrologyhadbeenmodified firstbyditches followedby the installationofdraintile.Soilpitsdugduringsiteinvestigationsconfirmedthepresenceofdraintileinthefield.

In general, soil investigations identified that organic and thin layers of mineral loam overlaidcoarse sand with cobbles at the north end of the area of interest, with increasing depths oforganics and silt loamand clay loam towards the southwest.Weanticipated thatwaterwouldpool through the winter and spring in the north-east corner but drain through the summermonths. In the south-west, soils retainwater through the summer andwe expected that year-roundgroundwaterwouldkeeppoolswetthroughdrymonthsdespite lossesto infiltrationandevaporation/evapotranspiration,particularlyasvegetationcoverre-grows.

Vegetationonsitewaspredominantlyreedcanarygrass,interruptedatthesouthendbyaclusterofdeadanddyingcottonwoodtreeswithanunderstoryofwillows.Arowofnon-nativesenescingLombardipoplarsandanunderstoryofwillowsformedanaturalboundarytotheeast;this1Hasectorwasnotaffectedbyconstructionactivitiesandprovidesopportunitiesforcontinuedwork.

4 SitePreparation

4.1 Hydrological preparation: June 2017 Phase III was inundated through the winter of 2016-2017 and still very wet in May 2017.ConstructionwasscheduledforJuly2017butitwasuncertainthatthefieldwouldbeaccessibletomachinerygiventhehighwatertable.Theseconditionsbeingpresentlateintheyearwereduetoa combinationof factors. First, previousworkshad successfully raisedof groundwater levels inPhases I and II on either side of Phase III; a condition enhanced by the diversion of water, bybeaver,eastfromGordon’sBrookintoPhaseI. Inaddition,theditchthatdrainsthesefieldshadnot been clearedmechanically by the Township of Langley inmany years, as flooding had notimpacted any landowners upstream. Although this is not a long-term concern for the restoredwetlands,itwasacutelyproblematicforconstructionofPhaseIII.


WecoordinatedwithBCFLNR,EnvironmentCanada,PearsonEcological(designandconstructionoftheGordon’sBrookrestoration)andMetroVancouvertogetpermissionstoalterbeaverdamsand water flows in Gordon’s Brook, as these waterways contain endangered Salish Suckers(Catostomuscatostomussp.).Beavershaddivertedall flowfromtheGordon’sBrookrestorationsiteintoPhaseI,resultinginseriousdegradationofCriticalHabitatforSalishSuckersinGordon’sBrookgiventhecertainanoxia in latersummermonths. Indoingso, theyalsocompromisedourabilitytoaccessPhaseIIIinJulyorAugust.OnJune6,2017weremovedtwobeaverdamsbyhandandclosedoffthebeaver-dugdiversionchanneltoPhaseI.

Inaddition,wecoordinatedwith theTownshipof Langley tohand-clean0Aveditch to improvedrainageoff the fieldand further lower thewater table (Figure2).Thisditch is fish-bearingandthereforeweusednon-mechanicalhandtools(rakes,hands)tocleantheditch.Reedcanarygrassplugs and rootswere lifted to the side of the ditch out of thewater by hand. ConveyancewasimprovedenoughtodrainPhaseIIIforconstructionaccess.

Figure2.0AveditchsouthofPhaseI(top)andsouthofPhaseIII(bottom)before(left),during(middle)andafter(right)hand-cleaning.TheditchdrainssouthacrosstheroadintoWashingtonStateatthewhiteroad-signseeninthetop-leftphoto,andrequiredcontinuouscleaningfromPhaseIIIwestwardstotheculvert.


4.2 Control of Invasive Species: 2015 - 2017

A detailed assessment of invasive species, control options and plans are available in theImplementationPlan.Below is a summaryof actionsundertaken in thepreparationof the fieldpriortoconstruction.

4.2.1 Himalayan Blackberry

HimalayanBlackberry(Rubusarmeniacus,formerlyRubusdiscolor)waspresentatthenorth-eastcorner of Phase III and was removed by mechanical methods in January 2016. We used anexcavator to remove theplants and grubout roots toprevent regrowth. Stems and rootsweretransportedtothehillsideinPhaseIIwhereblackberryremovedduringPhaseIIrestorationworkswasdeposited.Concentratedinthis location, itcanbecontrolledbymowingtherebycontrollingoccurrence. This method is anticipated to be successful with continued mowing by MetroVancouver.

4.2.2 Reed Canarygrass

ReedCanarygrass (Phalarisarundinaceae,RCG)dominatedGBIII,andcontrolof this specieswasconsideredcritical to thesuccessful restorationofnativevegetation in theproject.Weassessedseveralpotentialmethods forcontrol,manyofwhichrequirepost-construction implementation.However,given thatpost-constructioncontrolmethodsaremostlyunavailable tous (burningoraquatic-use herbicide application), we attempted pre-construction, multi-season chemicaltreatmentfor3yearsfollowedbytopsoilremoval.

Treatment began by mowing RCG in June 2015 in order to cut accumulated thatch and allowherbicidetoaccessregrowth.Thegrowthwasthentreatedwithglyphosate-basedherbicidesonOctober17,2015,followedbyadditionalapplicationstoregrowthonAugust5,2016andagainonJune30,2017.Regrowthwaspoorpriortoconstruction,particularlyinareasofthefieldthathadbeen underwater before ditch cleaning, with very little grass recovering from root matter.However, given that construction inherently disturbs soils and exposes seed, we anticipatedsignificantregrowthfromseedinuplandareas(Figure3).

Toavoidregrowthfromremnantrootandseed inthemarsh,wedugbelowtopsoilelevationtoexpose mineral soils and their historic seedbank content. This has been successful in previousprojects in the Fraser Valley to reduce regrowth of reed canarygrass and invite a historic plantcommunity into the restored site.However,diggingbelow the topsoil competedwithourotherdesign priority of creating shallow (<40 cm)marsh due to the thickness of the topsoil layer. Tobalancehabitatdesignandinvasivespeciescontrolsomesectionsweredugdeeptoremovereedcanarygrassseedandrootbank,andothersretainedsomeofthesoilstoensuremarshelevations.


Figure3.Stagesinchemicalcontrol.ByJuly2016thefieldhadbeenmowedandsprayedoncein2015–theimageshowsstrongrecoveryfromremnantrootsinJuly,thatwasthenkilledbyadditionalsprayinAugust2016.Recoveryoverthatwinterwassignificantlyreduced,particularlyinthewettersectionsofthefield.Oneadditionalspraywasappliedpriortoexcavationinordertofurtherimpactrecoveringplants.

5 Construction:July2017Construction was scheduled to begin in the southern lowest, wettest areas moving north tomitigate the effects of potential rainfall.We began construction by digging a trench across thesouthendofthefieldtoidentifyandcutdraintile.Excavationandre-sculptingbeganinthesouth-westmarshandponds,westoftheexistingplantcluster,thenmovedeastoftheclustertowardstheSouth-Eastmarshandponds.ConstructionoftheNorth-Westmarshandpondsfollowed,anda connector channel was then sculpted between the north-west and south-east sectors. TheNorth-East sector served as a staging area butwas not altered significantly; it offers additionalopportunitiesforrestorationintoashallowermarsh.WealsoinstalledtheWillowFarminPhaseII(see2016constructionreport)andimprovedroadaccessforblackberrycontrolinPhaseII.

5.1 Trench / Drain Tile Decommissioning Fifteen plastic ‘Big O’ drain tile lines were identified by digging a trench parallel to the 0 Avedrainageditch,approximately10mapartacrossthebreadthofthefield.Draintile linesrunningnorth-southwereinterruptedalongthelengthofthetrenchbyremovingsectionsandback-fillingwithsoil.Draintilewasapproximately1–1.3mdeep,belowtheinterfaceoforganicandmineralsoils. We left drain tile lines open into deeper ponds and pools as this line may be used byamphibians,fish,crustaceansorotherwildlifeasashelteringtunnel.


5.2 Construction Work began at the downstream end of the project in the south-west tomitigate the potentialimpacts of rainfall in he construction window. We recovered hydrology by removing drainagefeatures, and invited diverse ecosystem recovery by digging and piling soil to a variety ofelevationsaboveandbelowouranticipatedwaterlevels.Removedsoil(spoil)wasretainedonsiteandshapedintobermsthatrespectedviewsacrossthefieldfromtheroad.

Thebuilt landscape canbe roughly categorized into the south-west, north-west, south-east andconnectorsectors,eachcontainingmarsh,shallowwaterhabitatandsomedeeppools(Figure4).Thesouth-westsectorconnectstothedrivewayditchtothewestandthesouth-eastsectortotheeast,whichdrainsinto0Aveditchacrosstwooutlets.Thenorth-westsectordrainssouthacrossan outlet to the south-westmarsh, and connects to the south-east sector via a broad, shallowconnector channel. We did not dig in the north-east or east sectors, but have developed aproposaltocontinueworksinthisareaasthereisstrongpotentialforadditionalcomplexingandcreationofadditionalseasonallywettedhabitatinthiszone.

The constructedwetland both taps into groundwater and collects surfacewater. Gentle slopescollectwaterindeeppondsandprovideopportunitiesforshallowwaterusersatawidevarietyofwater levelsas thegroundwater lowers throughthesummer.Wedidnotusebermsorweirs inPhaseIII.Rather,wedisableddraintilestoreducewaterloss,anddugdowntothemineralsoilstocreate depth without further raising water levels. Excavation of the marsh and pools andplacement of spoil piles exaggerated existing contours that would have been historicallydiminished by agricultural activities over the years. Where possible, we placed deep poolsalongsideexistingvegetationtotakeadvantageoftheexistingshadeandcoverforwildlife.

Weretainedtheexistingfieldelevationatoutletstoavoidincreasingwaterlevelsabove‘natural’groundwaterelevation.Thatis,wedidnotconstructtheenclosingbermtoholdwaterbutratherto form landscape features. This avoids increasing hydrostatic pressure and the need for hardengineered features.Outletswere at least 10mwide and 5m across, avoiding the creation ofhigh-pressure pinch points across the wetland. We anticipated that water flows across theseoutletsovertimewouldcausethemtorillnaturallyandconnectthewetlandstotheditchatanequilibriumthatworksforthesite.Wealsoconsideredthatitmaybenecessarytore-visittheseoutlets in futureyears toassess their functionandmakemodifications (digdeeperorbuildup).Target water elevation was 42.6 m ASL, the elevation of the field at the ground-level outlets.However water elevations will clearly shift with the seasons, increasing in the winter to floodacrossmuchofthefield(floodplain,uptoapprox.43.4mASL).Wedidnothaveaspecificexpectedminimumgroundwaterelevationforsummermonthsgiventhedecommissioningofdraintile.Siteinvestigations indicated that groundwater level prior to drainage decommissioning wasapproximately42mASL.


Figure4.SummaryfigureofconstructedhabitatatAldergroveRegionalParkindicatingmajorfeatures.Outletelevationis42.6mASL.Depthsinlegendcalculatedfromintendedoutletelevations.


Soildisturbancecoveredapproximately3.4ha,withanadditional1.6haaffectedbytherecoveredhydrologyinthetargetfield.Acrosssomeofthefieldwedugbelowthetopsoiltoaccessmineralsoilsandremovereedcanarygrassseedsource.Theresultingareawillbecomeprimarilyshallowwatermarsh(0.4–1mdepth)ringedwithaperimeterofmarshandcontainingthreedeeppools(>1mdepth). In inthesouth-eastandnorth-westsectors,wedidnotdigall thewaytomineralsoils inordertoretainelevationsnecessarytoretaindepthssuitabletotherecoveryofamarshecosystem(0–0.4mdepth),ratherthanshallowwatermarsh.Inall,weanticipate,givenatargetwaterelevationof42.6mASL,0.07HaofDeepPool(>1mdepth),0.73HaofShallowWater(0.4– 1 m depth), and 1.06 Ha of Shallow Marsh (0 – 0.4 m depth), as well as up to 2.94 Ha ofFloodplain habitat and 0.21 Ha of Upland habitat (primarily high spoil piles) that we do notanticipatefloodingduringthehighestwaterlevels.

Figure 5. South-west marsh, shallow-water wetland and deep pool before construction, directly afterconstruction and after planting. White marker indicates location of the same standpipe (water levelmonitoringwell)ineachphoto.


Figure 6. South-west shallow water wetlands and marsh before construction, followingconstructionand fillingwithwater in the fall.Whitemarker indicates locationof samestump ineachphoto.

Microtopographic features, small channels, bumps, and pools were left behind to encourageformationofbothaerobicandanaerobicconditionswhichhelp improvebiogeochemicalcycling.Surfacesoil inthepondandriparianareasremainedroughandloose,witharangeofelevationsincorporatedintothebanks(Figure7).


Figure 7. North-westmarsh during and after construction. Orangemarker indicates same largestumpinbothphotos.

The constructed habitat contains a variety of wetland types and habitat features that targetOregon Spotted Frog, Northern Red-legged Frog and attempt to exclude American Bullfrog bydesign. The features also provide for avian and invertebrate biodiversity. Habitat features atmultiple scales create an abundance of variance for an abundance of life. Micro-featuresincorporateavarietyofdepthandshallows,a rough finish to increasesurfaceareaofsoils,anddifferingdensitiesandcombinationsofplantsandwoodydebris.

Figure8.ConnectorchannelfromtheNorth-WestmarshtotheEastmarsh.


Figure9.PoolateasternendofPhaseIIIrestorationatvariouswaterlevelsimmediatelyfollowingconstructiontoabovepoollevelsinJanuary2018.Thepoolwasplaceddirectlyalongsideexistingvegetationtomakeuseofexistingshade.Thispoolattractedbirdsimmediatelyafterconstructionduetotheprovisionofopenwateradjacenttoexistingcover.

Coarse woody debris provides important nutrient cycling opportunities for fungi, bacteria andinvertebratesthatformthebaseofthefoodweb,andalsoprovidescomplexstructuresthatserveas refugia for wildlife. Interactions between stable wood and moving water disrupt flows andincrease chaos in the built environment. In addition, woody debris, particularly around flowingwater, slows ice formation in thewinter and speeds thaw, resulting in thinner ice that ismoreeasilybrokenorstaysopentoallowairexchangeandbreathingholes foramphibiansandotherwildlife. Coarse wood was incorporated primarily in deep habitats to provide water-woodinteractions, refugia for wildlife, complexity to deep sites to reduce bullfrog densities, and toencourageinvertebratedevelopment.InPhaseIIIweanchoredthewoodtothesubstrateastheopen,deepnatureof theconstructedmarshcouldallowwoodto floatandmoveaway from itsoriginal location.Weattachedwoodwithnailsanchoredtobarssunk intothesubstratewithan


excavator. Ten-foot fence chain-link fence posts were sunk at least 6 feet into the ground toanchor,andattachedtowoodwithchainand8-inchscrews(Figure10.).

Figure10.Largewoodydebrisplacedatedgeofdeeppoolwithinmarshzoneandanchoredtothesubstratewithfenceposts,chainandheavyscrews.

6 RevegetationwithNativePlantspecies:October2017PlantingwascontractedtotheFraserValleyWatershedsCoalition(FVWC).Theirdetailedreportisappended and summarized here. Planting design considered climactic factors for drought andflood resilience, the provision of shade to reduce the recovery of invasive reed canarygrass inareasofshallowmarsh,andtheoperationalandvisualneedsofMetroVancouver,includingsight-linesandheritagefarmaestheticappeal.Plantingrequirementsanddesignweredevelopedduringpost-construction on-site meetings in August 2017 with Metro Vancouver, FVC and FLNROpartners(Figure11).

TheplantingconceptshowninFigure11 identifiedsight linesandplantingareasforaquaticandriparian plant species. Given a limited plant budget, the south-west marsh was prioritized forinitial planting, with an additional large planting planned for October 2018 that will addressadditionalareasofthemarsh.Figure12identifiesareasplantedin2017/18,mostlybyFVWCcrewwithassistance fromavolunteergroupofWaterandLandsOfficers fromBCFLNRwho learnedabouttheimportanceofwetlandsonthelandscape(Figure13).InadditiontoplantingatPhaseIII,pottedwillowswereplantedintheWillowFarmzoneofPhaseII,andaquaticplantsspeciesintheMarshzoneofPhaseItoincreasethedensityofplantsinthedevelopingmarsh(Figure14).


Figure11.ConceptplanforplantingPhaseIII,basedonas-built landscapeanddesiredsightlinesforvisualappeal.Darkgreenrepresenttreesandtallershrubs.Lightgreenrepresentlowershrubsandaquaticbenchesandbluerepresentpondedwater.

PlantswereinstalledinOctober2017inPhaseIII,andinPhaseIIinOctober2017aswellasMarch2018. In all, 4561 native plants were installed in Phase III, including 400 willow whips cut andtransplantedfromGordon’sBrook.InPhaseII,3901-gallonpottedvarietiesofwillows(scoulers,hookersandpacific)wereplantedinthewillowfarmzoneandanadditional1,974pottednativeplantsweredeliveredandplantedatPhaseIItoincreasevegetationdensity.

In total, 6,535 native trees, shrubs and aquatic plantswere added to Phases II and III affecting4,079m2(0.41Hectares).This includes3,104m2ofnewriparianandaquatichabitat inPhaseIII,104m2newand871m2ofinfilledriparianandaquatichabitatatPhaseII(Figure12).ImagesandplantlistsareshowninFiguresFigure13Figure14andinTables3Table4.

Figure12.PlantingcompletedinOctober2017andMarch2018.PlantinginPhaseIIIfocusedontheSouth-Westmarshandriparianspoilareas,andonthewillowfarmandmarshinfillinPhaseII.


Figure13.PlantingatPhaseIII.Aquaticplantslaidout,beingplantedbyBCFLNRWaterandLandsOfficers,andbeaverguarded.

Table3.NativeplantsinstalledinPhaseIIIinOctober2017.ScientificName CommonName Size TotalRhamnuspurshiana Cascara 2gal 6Betulapapyrifera PaperBirch 2gal 20Malusfusca PacificCrabApple 2gal 5Prunusvirginiana ChokeCherry 2gal 3Rubusspectabilis Salmonberry 1gal 80Rubusparviflorus Thimbleberry 1gal 60Cornussericea RedOsierDogwood 1gal 32Holodiscusdiscolor Oceanspray 2gal 58Salixlusiandra PacificWillow 1gal 30Salixscouleriana ScoulersWillow 1gal 30Salixhookeriana HookersWillow 1gal 30Rosanootkatensis NootkaRose 1gal 30Rosanootkatensis NootkaRose 2gal 10Physocarpuscapitatus PacificNinebark 1gal 90Myricagale SweetGale 1gal 145Lonicerainvolucrate BlackTwinberry 1gal 35Osmaroniacerasiformis IndianPlum 1gal 50Spiraeadouglasii Hardhack 1gal 235Carexobnupta Sloughsedge 1gal 200Experimentalaquaticmats 41traysw/72plugspertray Plug 2952Salixsp. Willow Whip 400Total 4,561


Figure14.PlantinginPhaseIIWillowFarmandMarsh.Topleft–Plantedwillowfarm.Topright–wapatomatsandgrowth.Bottom:infillplantinginPhaseIIMarsh.

Table4.NativeplantsinstalledinPhaseIIinOctober2017&March2018. ScientificName CommonName Size TotalMalusfusca PacificCrabApple 2gal 15Betulapapyrifera PaperBirch* 1gal 1Salixlusiandra PacificWillow 1gal 100Salixscouleriana ScoulersWillow 1gal 200Salixhookeriana HookersWillow 1gal 240Rubusspectabilis Salmonberry 2gal 25Rubusparviflorus Thimbleberry 2gal 25Cornussericea RedOsierdogwood 1gal 190Myricagale SweetGale 1gal 375Lonicerainvolucrate BlackTwinberry 1gal 100Spiraeadouglasii Hardhack 1gal 375Carexobnupta Sloughsedge* 1gal 200Sagittarialatifolia Wapato* 30x30cmmat 25Menyantaestrifoliate Bugbean* 1gal 15Ludwigiapaulstris Falseloosestrife* 9cm 15Carexutriculata Beakedsedge* 9cm 48Total 1,974*SomeorallplantedstockdonatedbyBC’sWildHeritagePlants(Approx.totalvalue~$1,100.00)


7 AnticipatedOutcomesandNextStepsThe depth required to access mineral soils, the methodmost successful in previous phases toreduce the return of reed canarygrass, was deeper than expected. We prioritized exposure ofmineralsoilsoverdepthtargetsinthewestmarshtoassesswhetherexposingmineralsoilwouldresultintheanticipatedreductionofreedcanarygrass,andprioritizeddepthtargetsinthesouth-eastmarshovermineralsoilexposure.Theresultingwetlandcontainsdeeppoolsthatarelikelytoprovide rearinghabitat formanynativeandnon-native fishspecies.However,wesuspect thesepoolsmay also attract American Bullfrogs and have the potential to strand fish in the summermonths. Continued monitoring will indicate further modification requirements; if we need tomodify outlet channels in order to reduce negative impacts to fish, or increase complexity toreduceBullfrogdensities.

7.1 Hydrology

Water level monitoring loggers have been installed in stand-pipes throughout the constructedwetland and will provide ongoing information regarding the hydrological recovery of the site.Designoutletlevelswereplacedat42.6mASL,whichwastheoriginalelevationofthefield.Waterelevationsdorisehigherthanthisinthewintermonths,whenthewetlandbackfillsfromtheditchon0Ave.

Giventhehydrologyofthesite,weanticipatethedevelopmentofmarsh,shallowwateranddeeppoolhabitats.Theremainderofthefieldwillfloodannuallyinthewinterbutwilldryoutquicklyinthe spring. Water levels will be reduced in the summer due to evaporation andevapotranspiration, but we anticipate that waterwill remain on-site for an extended period oftimegiventhedecommissioningofdrain-tilethroughoutthesite.Draintiledensitiesweregreaterthan we expected, suggesting that the field was extremely wet before installation.Evapotranspirationwillbegreatest in the first twoyears followingconstruction,withcakingandcrackingof soilsas theydry in thesummer,andwill slowly reduce in futureyearsasvegetationdevelopsagroundcoverovertheexposedsoilsandretainsmoisturethroughtheyear.

Deep pools will retain water through the summer but may trap fish in pools that becomedangerouslywarmwithunsuitableoxygenlevelforfishbeforeenoughshadedevelopstoprovidesuitable refugia. Thismay be particularly problematic in the first few years aswe anticipate analgalbloomassociatedwiththere-wettingofsoilsandtheassociatedreleaseofphosphorousintotheecosystemandwaterways.Thishasbeenobservedinotherrestoredagriculturalfieldsduetothehistoricover-applicationofphosphorous to the landscape,but appears to reduceover time(lessonsfromPhaseI).

We will monitor the pools in the spring and summer of 2018 to assess this; salvaging fish ifnecessaryandpotentiallydiggingdeeperchannelsthroughthewetlandtoexitat0Aveditch.Weanticipatethat0Aveditchwill revegetatewithin2yearsandcontinuetobackfill thewetland inthe future.At thesametime, thepresenceof thewetlandwill reduceconveyancepressuresontheditch,increasinginfiltrationandwaterstoragecapacityofthefield.


CurrentlyPhases I, II and III are connectedhydrologically through their connection to the0Aveditch,andeachPhaseisaffectedbytherecoveredgroundwatertableintheadjacentfields.AtthesurfacetheyareseparatedbyexistingdrivewaysuptoinfrastructureownedbyMetroVancouver.Thedrivewayswillneedmaintenanceandreplacementatsomepointinthefuture,atwhichtimewewillworkwithMetroVancouver to install culvertsunder the roadways thatwill connect thePhasesatthesurface.

7.2 Invasive species Wedonotanticipatesignificant regrowthofHimalayanBlackberry inPhase IIIasany remainingpatchesareeasilyaccessedbyMetroVancouver’smaintenancestaffforregularmowing.

Reed canarygrass recovery is anticipatedon theuplandareas and likely throughout the shallowmarsh ifwe arenot able touse aquatic-applicationherbicides or a firemaintenance regimeonsite.However, ifweareable to restrict regrowthbya combinationof chemical andmechanicalmeans(eg.swipeherbicideapplicationindrymonths,swamp-tromping)andshading,webelievewe can avoid the recovery of a reed canarygrass monoculture and ensure a more diverseecosystemintherestoredwetland.Wedonotexpecttoeliminatereedcanarygrassonsite.

The original intention for wetland restoration at Gordon’s Brook was to develop a potentialtranslocation site for the endangered Oregon Spotted Frog within the range of the invasiveAmerican Bullfrog. The purposewas to test restoration techniques thatwould provide suitablehabitatforOregonSpottedFrogswhilediscouragingthepresenceofbullfrogsbyhabitatdesign–ie. shallowmarsh <40 cm deep.We anticipate that American bullfrogs, an invasive amphibianspecies, will colonize Phase III given the presence of large shallow water habitats. However,bullfrogs are less likely to use shallowermarsh habitats, and have been observed to self-selectdeeperwatersectionsofcomplexwetlands.Ourhopeisthatthebullfrogswillavoidtheshallowerareasdespite theirpresence in themarsh,allowingnativeamphibianspecies touse themarshyedgehabitats.ThelocationsofbullfrogswithinthewetlandshouldbemonitoredandassessedasapartofanassessmentpriortotheintroductionofOregonSpottedFrogs.

7.3 Revegetation

RevegetationofPhase IIIwill continue in2018,withbudgetconfirmed foradditionalplanting inOctober2018. FraserValleyConservancywill partnerwithMetroVancouver toorganizea largevolunteerplantingeventandcelebrationoftheconstructionofthewetland.Plantingwillbuildontherevegetationeffortsalreadycompletedin2017/18,andfollowtheconceptplandevelopedbytheFraserValleyWatershedsCoalition.

7.4 Monitoring and Adaptive Management

The constructed wetland will require monitoring and maintenance. As the final outcomes areuncertain, an adaptive management approach that accepts several potential futures andmanagementplansmustbeconsidered.PhasesIIandIIIaremonitoredusingthesameprotocolsas Phase I in an expansion of the existing monitoring program. Post-construction habitatmonitoringbeganinautumn2017andwillcontinueforatleastfouryearsfollowingconstruction,


pending funding.Themonitoringplanwill informmanagement recommendationsdependentonhydrologicalandrevegetationoutcomes.AfinaldecisiononwhetherornotthehabitatissuitableforintroductionofOregonSpottedFrogsinthefuturewilldependontheinformationgathered.

7.5 Expansion

Thenorth-eastandeastsectorsofPhaseIIIprovideopportunitiesforfutureenhancementofthesite.Wehavedevelopedaproposedconcepttotakeadvantageofthisadditionalspace(Figure15.Concept design for Phase IIIB, complexing the north-east corner of the field and constructingadditional ponds in the east sector.), which would also be necessary to make a hydrologicalsurfaceconnectionbetweenPhases IIand III.AproposalwassubmittedtoHabitatConservationTrust Fund for additional work in 2018/19, to complement the final year of funding from theNational Wetland Conservation Fund, but was not successful. While the completed southernportionofPhase IIIoffersavarietyofdeeperpoolsand largewetterareasprovidinghabitat forspecies including salmonids, Salish Sucker and Northern Red Legged Frog; the goal of thisexpansionistoincreasehabitatvariability.Assuch,wefocusedonsmallerpoolswithanumberofchannelsprovidinginter-connectivityfororganismmovement.TheinspirationforthedesignwasderivedfromanhistoricalphotooftheFraserValley(includingthelostSumasLakehabitat)whichprovidesreferencetothetypeofwetlandhabitatspreviouslypresentintheFraserValley.

Figure 15. Concept design for Phase IIIB, complexing the north-east corner of the field and constructingadditionalpondsintheeastsector.


8 PublicEngagementPublicengagementinthe2017/18yearfocusedonadultprograms,spreadingthewordabouttheimportanceofwetlandsandthepossibilitiesthatcomewithwetlandrestoration(Table5).Intotal,therewere144visitorstotheGordon’sBrookWetlandscomplexandanadditional77participantsthatwere influencedby theactivities.Ourpartners inoutreachactivitieswere theFraserValleyWatersheds Coalition (FVWC), Langley Field Naturalists (LFN), Metro Vancouver (MV), LangleyEnvironmentalPartnersSociety(LEPS)andBCFLNR.Wealsodevelopedan8-minutevideoentitled“Trusting the land: Gordon’s Brook shallow marsh ecosystem restoration” on the process andimportance of marsh restoration in the Lower Mainland for the general public. FVC has hadsuccess in showing videos thatwehavemade about our projects towide audiences, and knowthat they successfullyengagenewaudiencesandengender interest in conservationactions.Welookforwardtosharingthisvideoonourwebsiteandwithourpartnersthroughsocialmediaandpublicevents.Thevideoisavailableonlineathttps://vimeo.com/264923624.

Table5.OutreachactivitiesatandaboutGordon'sBrookWetlandsOct2017-March2018.Date Group #Participants NotesOct4,2017

BCFLNRCoastAreaLeadershipTeam

55executivestaff

0.5hsitevisitwithFLNRCoastAreaLeadershipTeam,comprisedofmanagers,directors,andFLNRExecutive.Discussionregardingimportanceofrestorationandpartneringwithotherorganizations.Lead:KendraMorgan(FLNR)

Oct.6,2017

BCFLNRstaff–WaterandLandspermittingofficers,RegionalDirector

9front-linestaff

5hplantingnativespeciesatPhaseIII.ThisgroupwasspecificallytargetedtoeducateandengagepermittingstaffinthelocalBCFLNRofficeaboutwetlandsandrestorationprojects.Thesestaffproviderecommendationsfororagainstpermittingofactivitiesthataffectwaterandwetlandsonthelandscape.Planted~600plantsandsomewillowstakes.Leads:NatashaWilbrink(FVC),NatashiaCox(FVWC)

Nov.16,2017

Students–RickHansenSecondarySchoolBiology11Class

60students6adults

3hFieldtripwithnaturewalk,discussionabouthabitatrestoration,viewingwetlandcreatures,checkingtraps(fromshore),andobservingvegetation.Leads:AleeshaSwitzer(FVC)andKendraMorgan(FLNR)

Nov17,2017

GeneralPublic 55attendees 1.5hworkshopatMetroVancouver’sFallParksfest.DiscussedthehistoryofthealteredlandscapeandtheprocessofecologicalrestorationusingGordon’sBrookWetlandsasanexample.Lead:MonicaPearson

Nov21,2017

Targetedpublic–LandownerswithwetlandsinLangley

22attendees 1hpresentationregardingtheimportanceofbiodiversityonthelandscapeandcontributionofwetlandstoecologicalservices.Parnter:LangleyEnvironmentalPartnersSocietyLead:MonicaPearson

Mar19,2018

Naturalists 13naturalists 1.5htourofGordon’sBrookWetlands,discussingtheimportanceofwetlandsandhabitatrestoration.Lead:NatashaWilbrink(FVC)

Interim CONSTRUCTION REPORT Gordon’s Brook Wetlands …...of Shallow Marsh (0 – 0.4 m depth), as...

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