A Watershed Year forRMP & CEP:

Sources Pathways & Loadings 2002/03

Lester McKee & Jon Leatherbarrow

May 2003

Achievements 2002/03

• Made New Estimates of Sediment & Hg Loads from Central Valley WY 1995-2001

• Completed Urban Runoff Literature Review

• Carried Out Winter High Flow Monitoring on the Sacramento River at Mallard Island

• Carried Out Winter High Flow Monitoring on the Guadalupe River at San Jose

Organization of Watershed Science at SFEI

Regional Monitoring ProgramSFEI Watershed Program

Geomorphology

Historical Ecology

WaterQuality

GISSources Pathways

& LoadingsWork Group

Status & Trends

Contaminant Fate

Exposure & Effects

The Team

Sources Pathways& Loadings

SFEI Technical Staff

-Don Yee-Sarah Pearce-Jennifer Hunt-Nicole David-Lester McKee-Chuck Striplen-Ben Greenfield-Jon Leatherbarrow

Laboratories

-UC Santa Cruz

-AXYS Analytical

-Moss Landing Marine Laboratories

Work Group

-RWQCB (R2, R5)-Private Consulting-Regulated Community-USGS-Environmental Organizations-Universities

PeerReview

Two Technical Themes

Loadings

ProcessesMass

Timing

Downstream Fate

ProcessesMass

Timing

1995 1996 1997 1998 1999 2000 2001

An

nu

al S

edim

ent

Lo

ad (

Mt)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Del

ta O

utf

low

(cf

s)

0

100000

200000

300000

400000

500000

600000Average Sediment LoadWY 95-01 = 1.4 ± 0.2 Mt

Central Valley Loads - Desktop StudySPL & USGS

Working Together

Central Valley Loads – Desktop Study

SPL & RWQCB R5 Working Together

y = 0.3149x - 2.5945

R2 = 0.9505

0

10

20

30

40

50

60

0 50 100 150 200

Suspended Sediment (mg/l)

Par

ticul

ate

Hg

(ng/

l)

Water Year

Hg load (kg)

1995 701154

1996 25355

1997 612134

1998 644141

1999 23852

2000 162 36

2001 68 15

Mean 383 84

Loadings – Central Valley

Loadings – Central Valley

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

11/30/02 12/10/02 12/20/02 12/30/02 1/9/03 1/19/03 1/29/03

Flo

w (

cfs

)

Sac at Freeport (FPT)

Yolo Bypass nr Woodland (YBY)

FPT + YBY

Sampling Events

Central Valley Sediment & Contaminant Loadings Fate

Freeport2.2 Mt/year

Mallard Is.1.4 ± 0.2 Mt/year

Carquinez?? Mt/year

Golden Gate?? Mt/year

Data from USGS Sacramento Field Office

??

Small Tributaries – Desktop & Special Studies

Written reports• Davis et al., 1999• Davis et al. 2000• Leatherbarrow et al., 2001• McKee et al., 2002

Main conclusions• Small Tribs are a Significant Load• Not Enough Data to Estimate Loads• Sediment is an Important Vector• Sediment Processes Differ Greatly

Between Watersheds

Sediment Sources• Hillslope• Bed & bank• Urban runoff

Sediment loadings• Small Tribs 0.04 - 2.8 Mt / y• Central Valley 0.6 - 4.0 Mt/ y

Small Tributaries – Desktop & Special Studies

1

10

100

1000

10000

1 10 100 1000 10000

Watershed Area (sq. km)

Se

dim

en

t Exp

ort

(t /

sq

. km

)

Central ValleySmall Tribs

Bay Sediment Budget

Sediment Export Variability

Loadings – Small Tributaries

Collaborators and Labs

Larry Freeman USGSRand Eads RSLAXYS and MLML

Loadings – Small Tributaries

12/10 12/14 12/18 12/22 12/26 12/30 01/03

Sta

ge (

ft)

4

6

8

10

12

14

16

Tur

bidi

ty (

NT

U)

0

200

400

600

800Stage HeightTurbiditySampling Event

Loadings – Small TributariesPreliminary Results

Concentrations Loads Estimates (kg)

Mercury 0.2 – 18 g / L 60 - 600

PCBs* 7.7 –27 ng / L 0.6 - 1.2

DDT* 0.6 – 3.1 ng / L 0.1 – 0.2

* Four samples only

Sediment / Contaminant Fate – Small Tributaries

Guadalupe R.at San Jose

Airport60-600 kg / year

Guadalupe R. atAlviso Slough

?? kg / year

Dumbarton Bridge?? kg / year

????

Future Directions in Sources Pathways & Loadings

Central Valley• Sample a “Yolo Bypass” storm• Conduct a study to determine the contaminant budget for Suisun Bay

Local Small Tributaries• Conduct a desktop study to test methods of extrapolation spatially

and temporally limited data• Conduct another year of sampling on Guadalupe River• Start a new study in another known contaminated tributary• Determine the local fate of Hg and PCB loading from Guadalupe