Flow Regime and Water Temperature in the Willamette River ...
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Stewart Rounds USGS Oregon Water Science Center, Portland, OR with scads of assistance from USGS and USACE colleagues: Norman Buccola, Laurel Stratton, Annett Sullivan, Casie Smith, James White, JoJo Mangano, others Flow Regime and Water Temperature in the Willamette River, Oregon U.S. Department of the Interior U.S. Geological Survey photo by USGS
Transcript of Flow Regime and Water Temperature in the Willamette River ...
Stewart Rounds
USGS Oregon Water Science Center, Portland, OR
with scads of assistance from USGS and USACE colleagues:
Norman Buccola, Laurel Stratton, Annett Sullivan, Casie Smith, James
White, JoJo Mangano, others
Flow Regime and Water Temperature
in the
Willamette River, Oregon
U.S. Department of the Interior
U.S. Geological Survey
photo by USGS
Flow and Temperature in the Willamette River System 2
Take-Home Messages
Streamflow:
• Managed flow regime:
lower peaks, higher baseflow
Water temperature (WT):
• Summer WT in Willamette
River often exceeds standards
• Heat budget dominated by
large radiative fluxes
• Heat “memory” is short! – heat replacement in 2-3 days
• Dominant factors: – near dam: dam-release WT
– far downstream: flow, weather
• Off-channel areas provide
thermal diversity
Big Cliff
Detroit
(map from Corps of Engineers)
Streamflow at Salem, 1909-2018
Before Dams
After Dams
Summer flow has doubled.
6000
3000
3
Apr May Jun Jul Aug Sep Oct
2002
1,000
10,000
100,000
Str
eam
flo
w (
ft3/s
) 40,000
20,000
4,000
2,000
With Dams
Flow Comparison, With and Without Dams
No Dams
Simulated Flow, Willamette River at Salem
Flow augmentation decreases travel time,
and the additional water increases resistance
to temperature changes.
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Thermal Regime, 2011 — a Cool, Wet Summer
Provisional Data, Subject to Revision
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Thermal Regime, 2015 — a Warm, Dry Summer
Provisional Data, Subject to Revision
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Detroit Dam
463 feet tall
Multiple outlets:
• Spillway
• Power penstocks
• Upper regulating outlets
• Lower regulating outlets
Dam Operations Affect
Downstream Temperatures
Warm or cool
temperatures
accessed with
different
outlets
photo from U.S. Army Corps of Engineers
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5-1
5
5-2
4
6-0
2
6-1
1
6-2
0
6-2
9
7-0
8
7-1
7
7-2
6
8-0
4
8-1
3 6
7
8
9
10
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Do
wn
str
eam
Wate
r Tem
pera
ture
at
Nia
ga
ra (°C
)
Dam Operations Affect Downstream Temperatures
Power penstocks used
Spillway used
Spillway used
with Upper ROs
A fire shuts down
the Detroit Dam
powerhouse,
June 18, 2007
2007
Viola!
Temperature
Management!
But how far
downstream
does it persist?
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Release Temperatures from Detroit Dam
A Riverine Heat Budget
schematic from Bartholow (2000), USGS Open-File Report 99-112
Net heat input equals inputs minus outputs.
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conduction
The biggest energy fluxes are radiative.
Evaporation is moderately important;
conduction is not all that important.
Flow replaces heat content.
Willamette River Heat Budget on a Sunny, Hot Day
provisional results; subject to revision
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solar radiation
(“short wavelength”)
atmospheric radiation
(“long wavelength”) conduction
midnight noon midnight 6:00 am 6:00 pm
back radiation conduction
evaporation
stacked chart These heat fluxes are
substantial relative to
the total heat content
in the river.
Tracking Heat Sources in the N. Santiam River
Dam
Releases
Environmental
Inputs
Other
Inflows
down
to
29%
up
to
55%
16%
provisional results; subject to revision
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Using models, we can show
that heat-exchange fluxes
with the surrounding
environment soon swamp
out the heat content of any
individual upstream heat
source.
Tracking Heat Sources in the N. Santiam River
Dam
Releases
Environmental
Inputs
Other
Inflows
down
to
29%
up
to
55%
16%
provisional results; subject to revision
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At sites “far enough” downstream, dam operations and release
temperatures are “forgotten” and temperature is controlled mainly by
weather and residence time (flow).
Off-channel Areas Provide Thermal Diversity (Alcove at RM 107.5)
200m
photos by USGS
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This alcove near the mouth of
the Santiam River provides a
cold-water refuge.
Main channel
Alcove
https://or.water.usgs.gov/grapher/
Independence/Santiam (RM 96-108)
Santiam
River
Willamette
River
Independence
Buena
Vista
Ankeny
Wildlife
Refuge
Provisional Data, Subject to Revision
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Some off-channel areas are cool, and
some are warm, relative to the river.
Flow and Temperature in the Willamette River System 15
Take-Home Messages
Streamflow:
• Managed flow regime:
lower peaks, higher baseflow
Water temperature (WT):
• Summer WT in Willamette
River often exceeds standards
• Heat budget dominated by
radiative inputs and losses
• Heat “memory” is short! – heat replacement in 2-3 days
• Dominant factors: – near dam: release WT
– far downstream: flow, weather
• Off-channel areas provide
thermal diversity
Big Cliff
Detroit
(map from Corps of Engineers)
Contacts and References
Contacts:
Stewart Rounds and Laurel Stratton Garvin
USGS Oregon Water Science Center
[email protected], [email protected]
503-251-3280, 503-251-3234
Norman Buccola
U.S. Army Corps of Engineers, Portland District
503-808-4837
References:
• Bartholow, J.M., 2000, The stream segment and stream network
temperature models— A self-study course: U.S. Geological Survey Open-
File Report 99-112, 276 p.
(Available at https://pubs.er.usgs.gov/publication/ofr99112.)
• USGS Data Grapher: https://or.water.usgs.gov/grapher/
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