HowUnderstandingFieldtoStreamSedimentandPhosphorusFluxescanInformTargetedConservationinAgriculturalAreas:

LessonsLearnedfromthePleasantValleyProject

RebeccaCarvinUSGSWIWaterScienceCenter,Middleton,WI

LauraWardGoodUniversityofWisconsin‐MadisonSoils

FaithFitzpatrickUSGSWIWaterScienceCenter,Middleton,WI

Jasmeet LambaUniversityofWisconsin‐MadisonBio‐SystemsEngineering

SourcesandSinksofSedimentandNutrients‐‐ Objectives

Quantifyandtrackhowtargetedconservationreducesphosphorusandsuspendedsedimentfluxesatawatershedoutlet

Betterunderstandstorage,delivery,andlagtimesofphosphorusandsedimentfromuplandsanderodingbankstothewatershedoutlet

Providedatafordecision‐makingontargeteduplandconservationpracticesandstreamrestoration

Expandtoolsforunderstandingecology‐basedimpairmentsandTMDLs.

SourcesandSinksofSedimentandNutrients‐‐ Objectives

TotalPsawasignificantreductionin2013(p=0.1)

0 10 100 1,000 10,000

Tota

l P [l

bs] P

leas

ant V

alle

y (tr

eatm

ent)

0

1

0

1

00

1,0

00

10,0

00

Total P [lbs] Smith Conley (reference)

Sedimentsources,fluxes,andsinksactatdifferentspatialandtemporalscales

Soft sedimentSoft sediment

Valley bottoms

Hillslopes

BANK (SOURCE) SILTATION/SOFT SEDIMENT (SINK)

V = L x H x RL = Length of eroding bank (m)H = Height of eroding bank (m)R = bank retreat rate (m/yr)*V = volume of eroded sediment (m^3/yr)

*Retreat rate based on average from UW Pioneer Farm of 0.041 m/yr

LH

V = L x W x TL = Length of soft sediment (m)W = Width of soft sediment (m)T = thickness (m)V = volume of stored soft sediment (m^3)

LW

T

R

ChannelSedimentSourcesandSinksCalculator(2009‐10)

BankErosion

Fitzpatrick,etal.,indraft

Bank Erosion and Main CausesPleasant Valley

02004006008001000120014001600

0.0 2.0 4.0 6.0 8.0 10.0

Channel Slope (%)

Erod

ing Ba

nks To

tal A

rea (ft2)

Fluvial/masswastingCattleNone

Bank Erosion and Main CausesPleasant Valley

0

500

1000

1500

2000

0.0 5.0 10.0 15.0 20.0 25.0

Watershed Area (mi^2)

Erod

ing Ba

nks To

tal A

rea 

(ft2)

Fluvial/masswastingCattleNone

• TheamountoferodingbanksinPleasantValleywasnotsimplyrelatedtoasinglecause‐‐geomorphicagent,positioninthewatershed,orchannelslope.

• Muchofthemainstemhasriprapbankstabilization.

SoftSedimentDeposition

Fitzpatrick,etal.,indraft

• Amountofsoftsedimentwassomewhatrelatedtopositionwithinthewatershed.

• ReachatUSGSgagehadloweringamountofsoftsedimentfrom2009‐11.

0

500

1,000

1,500

0 10 20

Soft Sed

imen

t (tons/m

ile)

Watershed Area (mi^2)

Soft Sediment Deposition 

 20092011

Soft Sediment Deposition 

0

500

1,000

0 0.2 0.4 0.6 0.8 1 1.2

Channel slope (%)

Sedimen

t (tons/m

ile)

USGS Gage

USGSGage

WIDNRHabitatDataTrendsinSiltCoverage

SuspendedSedimentSourcesSedimentFingerprintingResults

Gage

2010 2011 2012

10

0102030405060708090100

Relative Co

ntrib

ution (%

)

Stream Banks

Woolands

Agriculture

Lamba,etal.,inpress

Woodlands

Streambanks

UPLAND SOIL EROSION0.8 tons/ac/y

SOFT SEDIMENTSAVINGS AND LOAN

1.2 tons/ac

Pre‐ImplementationWatershedSedimentBudgetUSGSGage

BANK EROSION0.06 tons/ac/y

ANNUAL WATERSHEDEXPORT (GAGE)0.15 tons/ac/y

(2007 -10 data, various sources)

SciencetoTargetedConservationConnectionsLessonsLearned

• Total phosphorus loads have decreased compared to the reference watershed.

• Sediment yields from farm fields are about 13 times higher than bank erosion (but sediment erosion from fields has add’l storage in hill slopes and floodplains).

• Bank erosion amounts vary but likely account for about 30% of annual export, but no more than 40%.

• There are about 8 yrs worth of annual export of suspended sediment stored in soft sediment deposition.

• For targeted conservation, consideration is needed of both agricultural conservation practices and stream restoration

Coon Creek Restoration, October 2010 Silver Spring Creek, Site 11, June 2010

STUDYPARTNERS,ASSISTANCE,ANDFUNDINGDaneCounty,LandConservationDivisionIowaCountyLandConservationDepartmentGreenCountyLandConservationDepartmentUniversityofWisconsin‐MadisonUniversityofWisconsin‐ExtensionU.S.GeologicalSurveyUSDANaturalResourceConservationServiceWisconsinDNRWisconsinDepartmentofAgriculture,Trade,andConsumerProtectionTheNatureConservancyLandownersandFarmersMonsantoCorporationMcKnightFoundationUSGScooperativeprogram

ResearchfundingprovidedbyUSDA‐NIFAaward#2009‐51130‐06049

Questions?