Erosion Control Field Guide

7/28/2019 Erosion Control Field Guide

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1. Protectandexpandmoisturestoringareasofthe

landscape.

2. Stabilizeac;veerosionandpreventfurtherdegrada;on.

3. Restoredispersedflowandincreaseinfiltra;onatevery

opportunity.

4. Cul;vaterestora;veplantcommuni;estobuildsoil.

5. Createsite-specificsolu;onsusingnaturalformsand

processes.

Formoreinforma;onvisit

www.DrylandSolu;ons.com

andwww.QuiviraCoali;on.org

GUIDING PRINCIPLES

By Craig Sponholtz & Avery C. Anderson

2010CSAA


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Alowgradecontrolstructurebuiltwithasinglelayerofrockonthebedofthe

channel.ORDsstabilizethebedofthechannelbyslowingtheflowofwater,increasingroughness,recrui=ngvegeta=on,capturingsediment,andgraduallyraisingthebedlevel

over=me.ORDsarealsopassivewaterharves=ngstructures.Thesinglelayerofrockis

aneffec=verockmulchthatincreasessoilmoisture,infiltra=on,andplantgrowth.Original

conceptdevelopedbyBillZeedyk.

Design&Construc;on

1. SelectareatobuildtheORD;digashallowfootertrenchandfillwithoneortworowsofrock,sothatnorockprotrudesmorethan2in/5cmabovethebedofthechannel.ThiswillserveasthesplashapronfortheORD.

2. ScaHernaIvegrassandwildflowerseedsintheareawheretheORDistobebuilt.3. StartbuildingatthefooterandconInueupstream,layingdownonelayerofrockhorizontally,asifyouwerebuildinga

rockwall.

4. OncetheORDiscompletelyfilledwithsediment,anotherlayercanbeaddedtofurtherraisethebedofthechannelandcapturemoresediment.TheoriginalORDbecomesthesplashapronforthenewlayer.

Orienta;onofRocks:PlacingrocksverIcallyiscalledbook-stacking,thismakesavery

strongstructure,especiallywhenusingsmallrocks.

tisalsoagoodwaytomakeaslightlyhigher

structure.

DirecIonofflow

2010CSAA

ONE ROCK DAM ORD

STEP1:Digtrench

andbuildfooter

STEP3:Startatfooterand

buildupstream

STEP2:SeedareaSTEP4:WhenORDfillsin,

addanewlayer

Book-stackedrocksareverIcallyplacedRocksplacedflat


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ONE ROCK DAM

PLANVIEW

Pool=Erosion

Crossover=DeposiIon

Pool=ErosionPROFILECrossover=DeposiIon

1.AlwaysposiIongradecontrolstructuresatmeandercrossovers.

3.AlwaysmaintainchannelcrosssecIontoprotectbanks.

2.PlacementatcrossoversmaintainsnaturalerosionanddeposiIonpaHerns.

Correct ncorrect

CROSSSECTION2010CSAA


4/10

Aheadcutcontrolstructurewherethefaceoftheheadcuthasbeenlaidbacktoa

stableangleofrepose(minimumofa3:1slope),andthencoveredwithasinglelayerofrockmulch.Themulchservestoslowrunoff,increasesoilmoisture,recruitvegeta=on,and

ul=matelypreventtheheadcutfrommigra=ngfurtherupslope.RockMulchRundownsare

ONLYtobeusedonlowenergyheadcuts,likethosefoundinuplandrillsandgullieswithsmall

catchmentareas,andwheresheelowcollectsandentersachannel.Originalconceptby

CraigSponholtz.

Design&Construc;on1. Selectalowenergyheadcutfortreatment.2. Determinetheextentofthe3:1slope.TakecaretobalancethecuXngrequiredtoachievea3:1slopevs.thepotenIaldisturbance

toexisIngvegetaIon.

3. LaybacktheheadcutbycuXngawaysoilfromthetopoftheface,andthenusethecutmaterialtofillthebaseoftheheadcut.Wherepossible,theRundownshouldbetheenIrewidthofthechannelbelowtheheadcut,orwhennochannelexists,thewidthof

theheadcutitself.Narrowheadcutsmayneedtobewidenedtoaccommodatetherockwork.Adjacentheadcuts,separatedby

unerodedfingersofearth,butleadingtothesamechannel,canbecombinedintoasingleRundownstructure.Knockdownthe

unerodedearthbetweentheheadcuts,anduseitasfill.

4.

Compactthefill.5. ScaHernaIvegrassandwildflowerseedandrakethesurfaceoftheRundown.6. DigashallowtrenchonthedownslopesideoftheRundownandfillwithonetotworowsofrock,sothatnorockprotrudesmore

than2in/5cmabovethebedofthechannel.ThiswillserveasthesplashapronfortheRundown.

7. CovertheenIresurfaceoftheRundownwithasinglelayerofrockmulch.ThecenteroftheRundownshouldbethelowestpointinthestructuresothatwaterwillnotrunaroundtheedges.

8. ConInuetolayrockonthesurfaceoftheRundownunIlyoureachtheheightoftheheadcutpour-over.Norocksshouldprotrudeabovethisleveltoallowwatertoflowfreelyoverthestructure.tisveryimportanttoavoidgapsintherockworkbecausegaps

causeweakpointsinthestructure.Fillgapswithsmallgravelifneeded.Toimprovedurability,youcanuseabiodegradablegeotexIle

meshtolinethesurfaceoftheRundownpriortolayingrocks.2010CSAA

ROCK MULCH RUNDOWN


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ROCK MULCHRUNDOWN*

1.Layout3:1slopeoveruplandheadcut.

2.Laybackslope,compactsoil,scaerseed.

3.Covernewslopewithcobblemulch.

4.Timeandprecipita;onwillproduceplantcover.

*Useonlyinlow

energyheadcuts(NOT

in-channelheadcuts!)

2010CSAA

splash

apron

headcutpour-over


6/10

Design&Construc;on1. Selectaheadcutfortreatment;shapeandlaybackthefaceoftheheadcuttocreateauniformsurfaceonwhichtobuild.2. Determinetheheightoftheheadcut.NextmeasureandmarkthelocaIondownstreamfromthefaceoftheheadcutthatistwoto

threeImes(2-3x)theheightoftheheadcut.AtthislocaIondigashallowtrenchandfillwithonetotworowsofrock,sothatno

rockprotrudesmorethan2in/5cmabovethebedofthechannel.ThiswillserveasthesplashapronfortheZuniBowl.

3. ScaHernaIvegrassandwildflowerseedsintheareawheretheZuniBowlistobebuilt.4. Gatherthelargestrocksavailable,andplacetheminarowjustupstreamfrom,andincontactwiththesplashapron.Theserocks

shouldsitatanelevaIonapproximatelythetotalheightoftheheadcut.Thiswillserveasthelowerpour-overoftheZuniBowl.

5. ArmortheboHomoftheplungepoolwithasinglelayerofrocks.PlacetheserocksatauniformheighttocreateastablefoundaIonfortherestoftheZuniBowl.

6. StarIngjustupstreamfromthelowerpour-over,laycoursesofrockaroundthefaceoftheheadcut.Thiswillformthewallsofthebowl.Maintaincontactwiththeshapedsurface.Thestructurewillhavemoreintegrityifbuiltwithlayersofoff-setrocksthatforma

slopingwallaroundtheheadcut,asopposedtomerelyliningthefacewithrocks.mprovethedurabilityofthestructurebyavoiding

gapsintherockwork.AsanextraprecauIon,youcanusebiodegradablegeotexIlefabrictolinethefaceoftheheadcutpriorto

layingrocks.

7. ConInuetolaycoursesofrockaroundthefaceoftheheadcutunIlyoureachtheheightoftheheadcutpour-over.Norocksshouldprotrudeabovethisleveltoallowwatertoflowfreelyoverthestructure.

8. ConstructaORDdownstreamfromtheZuniBowl.PlacetheupstreamedgeoftheORDapproximatelyfourtosixImes(4-6x)theheightoftheheadcutawayfromtheheadcutpour-over.

ZUNI BOWLAheadcutcontrolstructurecomposedofrocklinedstepfallsandplungepoolsthat

preventsheadcutsfromcon=nuingtomigrateupstream.ZuniBowlsstabilizeac=vely

erodingheadcutsbydissipa=ngtheenergyoffallingwaterattheheadcutpour-over

andthebedofthechannel.Thestructureconvertsthesinglecascadeofaneroding

headcutintoaseriesofsmallerstepfalls.ZuniBowlsalsoservetomaintainsoil

moistureonthefaceoftheheadcut,encouragingtheestablishmentofprotec=ve

vegeta=on.OriginalconceptdevelopedbyBillZeedykandthepeopleofZuniPueblo.

2010CSAA


7/10

ZUNI BOWL

lowerpour-over

[heightofheadcutpour-over]

splashapron

headcutpour-over

2-3xheightofheadcut2010CSAA

onerock

dam

4-6xheightofheadcut

plungepool

plungepool


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MEDIA LUNATherearetwotypesofMediaLunastructuresbothusedtomanagesheetflow

andpreventerosion.Sheetflowcollectors(=psDOWN)preventerosion(i.e.

headcuts)attheheadofrillsandgulliesbycrea=ngastabletransi=onfromsheet

flowtochannelflowatthecollec=onpoint.Sheetflowspreaders(=psUP)areused

onrela=velyflatgroundtodisperseerosivechannelizedflowandreestablishsheet

flowwhereitonceoccurred.OriginalconceptdevelopedbyVanClothier,and

expandeduponbyCraigSponholtz.

Design&Construc;on1. denIfywhichtypeofMediaLuna(i.e.IpsUPorIpsDOWN)isappropriateforthetreatmentsite.2. fthetreatmentsiteisatthecollecIonpointofanetworkofrills(


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MEDIA LUNASheetFlowSpreader(=psUP)

Spreadsrunofffromchannelsand

iniIatessheetflow.

SheetFlowCollector(=psDOWN)

Preventsdevelopingrillsandgullies

fromerodingupslope.

2010CSAA

collection

point

sheet flow

splash

apron


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OneRockDam RockMulch

Rundown

MediaLuna(;ps

UP)

ZuniBowl

2

010CSAA

W

henpossible

usematerialsavailableon-site.

N

OTE:manytypeso

frockcanbeused

tobuildthesestructures.

Formoreinform

a>onvisitwww

.DrylandSolu>o

ns.com

andwww.QuiviraCoali>on.org

Erosion Control Field Guide

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