Monitoring of Groundwater and Surfacewater Interactions on the Walla Walla River

Graduate Student: Starr Silvis

Major Professor: John Selker

Field Coordinator: Bob Bower

outline

Presentation Outline

Location and features of the basinBackgroundGoalsMethods

Chemical SignatureMini-piezometersTemperature Profiling

ResultsDiscussion

background

Location of the Walla Walla River Basin

background

Water Resources for the Basin

Surface waterNorth Fork and South Fork

GroundwaterAlluvial aquiferBasalt aquifers

background

Monthly Mean Flows

0

50

100

150

200

250

300

350

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Mon

thly

Mea

n Fl

ow (

cfs)

South Fork

North Fork

22 years of data 1969 - 1991

background

Walla Walla River Returns!

All river water above levied section (~100 c.f.s.) diverted for irrigation since turn of the century from June – September

1998 American Rivers lists Walla Walla River as one of the top 20 most endangered rivers in the U.S.

Bull trout and Steelhead E.S.A. listed in 1998 and 1999

Irrigation districts pledge to leave flow in the mainstem of the Walla Walla River; sign agreement with U.S.F.W. 2000 – 13 c.f.s 2001 – 18 c.f.s. 2002 – 25 c.f.s 2003 - ?

background

Summer 1999

Summer 2002

background

Low Flow Limitations

2000 - all 13 c.f.s. percolated from the surface

Possible causes

In-stream gravel miningNaturally high hydraulic conductivity (Schälchli,

1995,1992)Large hydraulic gradients due to low aquifer levels

background

Aquifer Recharge

Irrigation ditch lossesPrimarily unlined ditches

Stream lossesWinter rechargeNow – summer recharge too

goals

Study Goals

Provide quantitative framework for the surface and groundwater exchanges

Determine influent / effluent nature of levied section

Quantify river losses

Identify seasonal patterns

Estimate alluvial aquifer recharge

SW/GW Overview

Water flows from the stream into the subsurface

Water flows from the subsurface into the stream

methods

Methods

Chemical Signature

Mini-piezometers

Temperature profiling

Ditch loss

methods

Chemical Signature Requirements

Conservative and naturally occurringChloride and Sulphate

GW/SW must have distinctly different concentrations

Ease of analysisIon chromatography

methods

Chemical Signature

Grab Sampling Mainstem Walla Walla River Shallow aquifer wells10% duplicate sampling

Data AnalysisMixing space diagramsLinear RegressionsMass Balance

methods

Chemical Signature; Mass Balance

Qsin

Csin

Qgw Cgw

Qs

Cs

Upstream sampling point

Downstream sampling point

Accumulation = In – OutAccumulation = 0In = Out

methods

Groundwater Sampling Sites

Tumalum Bridge

Nursery Bridge

Milton-Freewater

Hwy 11

Walla Walla River

Red dots are wells

methods

In-Stream Sampling Sites

Nursery Bridge

Tumalum Bridge

Milton-Freewater

methods

Mini-Piezometers

dl

Vertical Hydraulic Gradient = dh/dl

Streambed surface

Mid-point of perforations

Stream surface

dh

outline

Mini-piezometer

Temperature profiling device

methods

Temperature Profiling

methods

Temperature Profiling

Analytical MethodsHYDRUS-2D (Šimůnek et al., 1999)

Computer model using inverse processes to solve for vertical flux

Sine Wave FittingStallman’s (1965) equation for a sine wave fit to

the data

methods

Temperature Profiling

HYDRUS-2D

Sophocleus (1979)

iiw

jij

ix

TqC

x

T

xt

TC

])([)(

Conduction Convection

methods

Temperature Profiling

Sine Wave FittingStallman (1965)

Solution for diurnally heated and cooled boundary condition

t

Tc

z

Tvc

z

Tk oo

2

2

Tz (t) = ΔT e-az sin (2πt/τ – bz) + Taz

methods

Temperature Profiling; No Flux

HYDRUS-2D no flux simulation R2 = 0.95

methods

Ditch Loss StudyInstalled dam

Covered with plastic

Allowed to fill to capacity

Shut off water supply

Measured time and depth of draining for 6 hours

results

Chemical Signature; GW

0.00

5.00

10.00

15.00

20.00

25.00

30.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

Chloride (mg/l)

R2 = 0.89

results

Chemical Signature; SW

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0.4 0.6 0.8 1.0 1.2 1.4 1.6

Chloride (mg/L)

R2 = 0.96

results

Chemical Signature; Mass Balance

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

5 10 15 20 25

Site Number (SW-)

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

12-J ul

31-J ul

14-Aug

12-J ul

31-J ul

14-Aug

Tumalum Bridge

Filled symbols correspond to left axis, open symbols correspond to the right axis

GW dominates

SW dominates

Qsin

Qgw

results

Mini-piezometers Average Vertical Hydraulic Gradient

-1.80

-1.60

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

Piezometer site ID

Vert

ical

Hyd

raul

ic G

radi

ent

(cm

/cm

)Nursery Bridge Tumalum Bridge

duplicatesduplicates

results

Temperature Profile

10

12

14

16

18

20

22

8/17/0212:00

AM

8/17/024:48 AM

8/17/029:36 AM

8/17/022:24 PM

8/17/027:12 PM

8/18/0212:00

AM

8/18/024:48 AM

8/18/029:36 AM

8/18/022:24 PM

8/18/027:12 PM

8/19/0212:00

AM

time

degr

ees

(C)

5

4

3

2

1

results

Temperature Profiling; Sine Wave

12

13

14

15

16

17

18

19

20

21

22

8/11

/02

7:01

8/11

/02

12:0

1

8/11

/02

17:0

1

8/11

/02

22:0

1

8/12

/02

3:01

8/12

/02

8:01

8/12

/02

13:0

1

8/12

/02

18:0

1

8/12

/02

23:0

1

8/13

/02

4:01

Date

Te

mp

(C

)logger 3 data

logger 3 f it

logger 2 data

logger 2 f it

logger 1 data

logger 1 f it

M 5.5 August 14

results

Temperature Profiling; HYDRUS-2D

12

14

16

18

20

22

0.0 0.5 1.0 1.5 2.0 2.5

Time [days]

M-5.5 (August 14th)

results

Temperature Profiling; Sine Wave vs. HYDRUS-2D

y = 3.29x0.73

R2 = 0.55

y = 1.98x0.71

R2 = 0.78

1

10

100

1000

1 10 100 1000

HYDRUS-2D estimation of q (cm/d)

Sta

llman

's s

ine

est

imat

ion

of q

(cm

/d)

Pink are results using loggers 3 to 2 (15 cm)

Blue are results using loggers 3 to 1 (30 cm)

results

Mini-piezometers

-140

-120

-100

-80

-60

-40

-20

0

20

40

06/08/01 07/28/01 09/16/01 11/05/01 12/25/01 02/13/02 04/04/02

date

mea

n he

ad d

iffer

ence

(cm

)

results

Seasonal Patterns; Mini-Piezometers

0.00E+00

2.00E-03

4.00E-03

6.00E-03

8.00E-03

1.00E-02

1.20E-02

1.40E-02

1.60E-02

1.80E-02

2.00E-02

M4-M5a M5b-M6 M6-M7 M7-M8

Site IDs

K (

cm/d

ay)

july

aug

oct

K = -Q / (A dh/dl)

results

Seasonal Patterns; Temperature

0

50

100

150

200

250

300

350

6/13/2002 7/3/2002 7/23/2002 8/12/2002 9/1/2002 9/21/2002 10/11/2002

Date

Q (

cm/d

ay)

HYDRUS-2D

Sine

HYDRUS-2D average

results

Ditch Loss

Infiltration estimate 204 cm/d

discussion

Conclusions

Effluent river on section studiedEstimated flow loss

0.3-0.76 m3/s using temperature estimates0.43-0.63 m3/s using in-stream flow

measurements

Seasonally hydraulic conductivity decreased factor of 2-4 using temperature profiling estimatesfactor of 2-100 using mini-piezometer estimates

discussion

Implications for GW recharge of the shallow aquifer

Assuming only 50 km of ditches with an average infiltration rate of 204 cm/d 2 * 107 m3 / yrOn an area of 538 km2 and a porosity of 0.27

equivalent to 23 cm of water

Assuming 5 months at max infiltration rate of 310 cm/day using temperature profiling estimates 1.8 * 108 m3 / yr On an area of 538 km2 equivalent to 1.2 meters of

water

discussion

Future Work

Determine seasonal patterns in aquifer levelsContinual static level measurements

Installed pressure transducers in 12 wellsChemical signature

Spatial mapping of anion concentrationsDitch loss studies

Inflow out flow measurementsTemperature profiling of ditch bedEvapotransporation

Area of influence of infiltration from the river Instrument a transect across the entire levyLeave devices in place for the entire season

Thanks to;

WWBWC and OWEB for caring enough about the watershed to fund this project

Bob Bower for EVERYTHING!

Community in the Walla Walla Watershed

John Selker for tireless enthusiasm and myriad of good ideas

Emilie Baer for her hard work in the field and in data analysis

My committee; Julia Jones, Jeff McDonnell, Roy Haggerty, and Mike Gamroth

OSU Bioengineering Department; June Rice, Elena Maus, David Rupp, Kristy Warren, Ruth Boitz, Linda

Hoyser

Friends and Family for continual support

Especially thanks to Jeff Silvis for still becoming my husband even after the trials and tribulations of moving across the country and graduate school.