tdg characterization of the lower columbia...

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TDG Characterization of the Lower Columbia River

Water Quality TeamPortland Oregon, December 9, 2005

Mike SchneiderCE-ERDC-EL

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• Compilation of TDG data – Bonneville Dam to Wauna Mill (RM 42-146)– Parameters

• TDG, Temp, DO• Flows (Bonneville and tributaries)• Stage• Channel configuration

– Date Sources - COE• Fixed monitoring stations

– BON, CCIW, WRNO, SKAW, CWMW, KLAW, WANO– 1990-2005 hourly frequency

• Research Studies– DGAS program – 3 pool studies– Evaluation of CWMW station– 2002 TDG production in Spill post-deflector– 1999 TDG production in Spill– 2005 KLAW & WANO (2 weeks)

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• TDG properties and processes– Bonneville TDG loading

• Spill• B2CC• Powerhouse releases• Auxiliary flows

– Mixing Zone • Extends through the Ives/Pierce Islands reach

– Well mixed open river– Exchange air/water (degassing)

» Wind induced– Temperature– Biological productivity– Tributary inputs

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• Bonneville Operations– Historical perspective

• 1938 2 units online producing power• 1943 completion of 1st Powerhouse (136 kcfs capacity)• 1957 The Dalles Dam completed• 1976 “flip lips” on 13 of 18 spill bay• 1982 completion of 2nd Powerhouse ( 152 kcfs capacity)• 1984 Revelstroke Dam completed• 1995 spill for fish passage policy adopted• 2002 redesigned “flip lips” added to bays 1-3, 16-18• 2004 Bonneville 2nd powerhouse corner collected operational

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Columbia River Average Annual Flow and Spill at Bonneville Dam, 1938-2005

0

50

100

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200

250

30019

38

1940

1942

1944

1946

1948

1950

1952

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1962

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1974

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1982

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1990

1992

1994

1996

1998

2000

2002

2004

Year

Flow

(kcf

s)

Flow (kcfs) Spill (kcfs)

Mica Dam

Revelstoke Dam

Figure xx Average annual Columbia River Flow and spill at Bonneville Dam 1938-2005

Bonneville2nd PH

AdditionalFlow Deflectors

InvoluntarySpill for fish

Flow DeflectorsBonneville1st PH

Average

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• Seasonal Bonneville Operations– Involuntary spill April-August

• TDG capacity 115%/120%/125% at tailwater station and Camas/Washougal

– Spring Creek Spill in March– B2CC operation only with spill– Involuntary spill December-July

7Monthly summary of days with spill greater than 10 kcfs at Bonneville Dam from 1990-2005

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• Tributary Flows– Willamette, Cowlitz, Lewis, Kalama, Sandy, Washougal– Flow Contribution

• 20-22 percent during the summer• 35-41 percent during the winter

– TDG Contribution• Willamette Falls (as high as 120%)• Little TDG data• 4 percent reduction in CR TDG pressure for the following

– TDGBON=120%– TDGtrib=100%– Qtrib/Qcr=0.20

9The Columbia River Tidal Pool Reach below Bonneville Dam

Ives IslandI-205 Bridge

Multnomah Falls

Willamette River

Washougal River

Sandy River

Lewis River

Kalama River

Cowlitz River

Bonneville Dam

SKAW

WANO LOPW

SHNO

VANW

BON

Stage gages

Water quality gages

SKAW

CWMW

CCIW

Depth Basedon CRD

WRNO

KLAW

WAUO

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Lower Columbia River Average Monthly Flow (kcfs) 1993-2005

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100

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350

400

1 2 3 4 5 6 7 8 9 10 11 12

Month

Flow

(kcf

s)

WillametteSandyLewisCowlitzBon

40.4 35.232.9

28.6

23.8

41.6

22.0

20.2

21.1

24.3

34.9

27.2

Figure xx Lower Columbia River Average Monthly Flow Composition, 1993-2005(Percent contribution from tributaries noted on this figure)

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• Columbia River Stage– Bonneville Tailwater function of total river flow

• 15 kcfs change ~ 1 ft stage change• Ives Island area responds similarly• Wide range of tailwater elevations (8-36 ft)• Habitat Influences

– Stranding– Depth Compensation for TDG exposure– Water and Temperature exchange

• TDG exchange– Deflector submergence– Available aerated depth

– Tidal influence on river stage increases with decreasing flow and distance from Bonneville Dam

13Stage @ ~153 kcfs (weekly avg)

Stag

e (fe

et, N

GVD

)

Tota

l Riv

er D

isch

arge

(kcf

s)

14Stage @ ~313 kcfs (weekly avg)

Stag

e (fe

et, N

GVD

)

Tota

l Riv

er D

isch

arge

(kcf

s)

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• Columbia River Channel– Channel in the Gorge (rm 122-146)

• Shallow and wide• Narrow and deep• Average depth 24-34 ft at low flow• Channel Width ranges from 900-6200 ft

16Ives Island rm 142

17Multinomah Falls rm 135

18Sand Island rm 130

19Camas/Washougal rm 122

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• TDG Saturation– Bonneville Dam Spillway

• 2002 Spillway flow deflectors at El. 7 added bays 1-3, 16-18• Flow deflectors at Bays 4-15 at El. 14 ft• TDG function of specific spillway discharge and tailwater channel

depth• Non-uniform TDG pressures exiting spillway channel at spill > 120

kcfs• Spillway capacity as limited by tailwater fixed monitoring station

CCIW is 150-160 kcfs• Spill capacity can be limited by the 115% criteria measured at the

CWMW fixed monitoring station

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105

110

115

120

125

130

135

140

0 2 4 6 8 10 12 14 16 18 20

Specific Discharge (kcfs/bay)

Tota

l Dis

solv

ed G

as S

atur

atio

n (%

)

1999 Bays 2,3, 16, 172002 Bays 1-3,16-18

Figure 28. Total dissolved gas saturation as a function of specific spill discharge in the Bonneville spillway exit channel. (1999 – No deflectors, 2002 - El. 7 ft deflectors)

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y = 0.1241x + 106.04R2 = 0.9388

y = 0.105x + 106.84R2 = 0.9536

y = 0.058x + 111.2R2 = 0.8864

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115

120

125

130

135

140

0 50 100 150 200 250 300

Spillway Discharge (kcfs)

TDG

Sat

urat

ion

(%)

ps-maxBONTWP1ps-avgLinear (ps-max)Linear (ps-avg)Linear (BONTWP1)

Total Dissolved Gas Saturation in the Bonneville spillway exit channel as a function of spillway discharge, April 10-June 5, 2002 (ps-max maximum cross sectional, ps-avg average cross sectional, BONTWP1-Bradford Island station)

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PH 230 kcfs

120%

135%

130%

125%

Flow duration for Columbia River at Bonneville Dam, Oregon 1 April through 31 August

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• TDG Saturation– Voluntary spill

• TDG levels range from 110-120 %– Forced spill

• TDG levels range from 120-130% – TDG Decreases with distance from Bonneville

• Lose from 2-3% by CWMW rm 122• Rate of loss is a function of magnitude of TDG at Bonneville

– First order exchange• Wind events can increase degassing• Temperature induced TDG variation• Biological Productivity DO induced TDG variation

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• TDG Saturation– Lateral TDG variation outside mixing zone is small– Temporal and spatial TDG variability is greatest just below the

dam– Day / Night Spill policy generates fronts of elevated TDG

saturation that propagate downstream– TDG content of powerhouse release mimic forebay TDG levels

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155

12/1/96 12/21/96

1/10/97 1/30/97 2/19/97 3/11/97 3/31/97 4/20/97 5/10/97 5/30/97 6/19/97 7/9/97 7/29/97 8/18/97 9/7/97 9/27/97

TDG

Sat

urat

ion

(%)

-600

-500

-400

-300

-200

-100

0

100

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600

Flow

(kcf

s)

wanoklawcwmwskawwrnobonQtotalQsp

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155

3/11/97 3/31/97 4/20/97 5/10/97

TDG

Sat

urat

ion

(%)

-600

-500

-400

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-200

-100

0

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600

Flow

(kcf

s)


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2/24/98 3/16/98 4/5/98 4/25/98 5/15/98 6/4/98 6/24/98 7/14/98 8/3/98 8/23/98 9/12/98

TDG

Sat

urat

ion

(%)

-600

-500

-400

-300

-200

-100

0

100

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600

Flow

(kcf

s)


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4/5/98 4/25/98 5/15/98 6/4/98

TDG

Sat

urat

ion

(%)

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-100

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Flow

(kcf

s)


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River Mile

TDG

Pre

ssur

e (m

m H

g)

199719941995199619982005

Columbia River Mile 42-145 Monthly Average TDG Saturation for June 1994-2005

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95

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30 40 50 60 70 80 90 100 110 120 130 140 150

River Mile

TDG

Pre

ssur

e (m

m H

g)

septAugJulyJuneMayApril

Columbia River Mile 42-145 average monthly TDG saturation for 1998

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105

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125

130

30 40 50 60 70 80 90 100 110 120 130 140 150

River Mile

TDG

Pre

ssur

e (m

m H

g) AugJulyMayAprilJuneseptMarch

Columbia River Mile 42-145 average monthly TDG saturation for 1997

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y = 0.7987x + 20.838R2 = 0.9309

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105

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130

100 105 110 115 120 125 130

TDG Saturation at CWMW (%)

TDG

Sat

urat

ion

at K

LAW

(%)

Monthly Average TDG Saturation at CWMW vs KLAW

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• Water Temperature – Gas Laws

• 1 C change in Temperature can cause a 2-3% change in TDG pressure– Temperature of CR does respond to daily thermal inputs

– Daily temperature range can be 2-3 C

– Water Temperature change is small from Bonneville to Wauna Mill (monthly trends)

– Tributary temperatures were not reviewed

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6/8 6/9 6/10 6/11 6/12 6/13 6/14 6/15 6/16 6/17 6/18 6/19 6/20 6/21 6/22

Tem

pera

ture

(°C

)

-500

-400

-300

-200

-100

0

100

200

300

Flow

(kcf

s)

CWP3 CWP4 CWP6B CWP6M CWP6S BON

CORBETT CWP1 CWP2 Qspill Qtotal

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0 20 40 60 80 100 120 140 160

River Mile

Wat

er T

empe

ratu

re (F

)

MarAprMayJuneJulyAugustSept

Columbia River Mile 42-145 monthly average temperatures from March-September 2005

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• Dissolved Oxygen – Gas Laws

• 1 mg/l change in DO can cause a 2% change in TDG pressure– Typical daily DO variation is from 0.4-0.8 mg/l– DO content in spill is under represented compared to atmospheric

ratios

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14

15

6/8 6/9 6/10 6/11 6/12 6/13 6/14 6/15 6/16 6/17 6/18 6/19 6/20 6/21 6/22

Dis

solv

ed O

xyge

n C

once

ntra

tion

(mg/

l

-500

-400

-300

-200

-100

0

100

200

300

Flow

(kcf

s)

CWP3 CWP6M G49 CR46 CCWP6B CORBETT Qtotal Qspill

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• TDG Habitat – Depth Compensation

• TDG pressure = Total Pressure=Patm+Phydrostatic• Substrate below compensation depth is protected

– Shallow habitat is at greater risk• Compare percent habitat exposed to supersaturated conditions

– 115 % saturation = 5 ft of depth – CR near CWMW 21% river is above depth of compensation– CR upstream Bon 8% river isl above depth of compensation

– TDG Hazard Delineation• Channel configuration• River stage• TDG pressure• Map of substrate dewatered, above depth of compensation, below depth of

compensation

41Camas/Washougal rm 122

42TDG hazard map for TDG=115% near Camas/Washougal Blue-below CD Yellow-dewatered Red-above CD

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• Conclusions

• Recommendations– Develop better understanding of TDG management in critical

habitat areas• Powerhouse 2 versus 1 operation• Spill pattern modification to generate less TDG• Water stage, Bathymetry, TDG interaction

tdg characterization of the lower columbia...

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