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Transcript of Understanding the Big Picturesuzanneoel.com/docs/misc/PMRA_Stelfox_Bow_Basin_20140601.pdf ·...
11
The 2013 Bow River Basin FloodThe 2013 Bow River Basin Flood Understanding the Big PictureUnderstanding the Big Picture
A Presentation to theA Presentation to thePriddisPriddis
MillarvilleMillarville
Residents AssociationResidents Association
66
The Human Component The Human Component (Natural Floods versus Economic Floods)(Natural Floods versus Economic Floods)
88
This is a relatively New LandscapeThis is a relatively New Landscape
• Most recent glacial
event occurred
between 20,000 and
9,000 years
• Relatively young
landscape for soils and
vegetation
• Action of glaciers
ground up rock and
increased availability of
minerals; enhanced
plant growth and soil
formation
1212
The Anatomy of the Bow River BasinThe Anatomy of the Bow River Basin Source: ALCES OnlineSource: ALCES Online
1313
The Basin and Selected CommunitiesThe Basin and Selected Communities
S
W
N
E
Canmore
Calgary
Cochrane
OkotoksHigh River
Turner Valley
Airdrie
Lake Louise
Bragg Creek
Black Diamond
Banff
PriddisMillarville
Chestermere
Crossfield
Longview
Redwood Meadows
1414
The Major Plumbing Pipes of the Bow River BasinThe Major Plumbing Pipes of the Bow River Basin (including alluvial aquifers)(including alluvial aquifers)
S
W
E
Bow River MainstemGhost River DrainageJumping Pound DrainageNose Hill DrainageElbow River DrainageFish Creek DrainageSheep River DrainageHighwood River DrainageExamples of Alluvial Aquifer Channels
N
1515
InterInter‐‐Annual Variation in Precipitation and FlowAnnual Variation in Precipitation and Flow AVERAGE YEARAVERAGE YEAR
S
W
N
E
1616
InterInter‐‐Annual Variation in Precipitation and FlowAnnual Variation in Precipitation and Flow DRY YEARDRY YEAR
S
W
N
E
1717
InterInter‐‐Annual Variation in Precipitation and FlowAnnual Variation in Precipitation and Flow WET YEARWET YEAR
S
W
Redwood Meadows
N
E
2121
Mean Annual Precipitation (mm)Mean Annual Precipitation (mm) Source: ALCES OnlineSource: ALCES Online
2323
The Basic Math of Water in the Upper BowThe Basic Math of Water in the Upper Bow Annual Annual AnnualAnnual
Precipitation with Average Rainfall EventsPrecipitation with Average Rainfall Events
Precipitation (~780 mm)Precipitation (~780 mm)
Evapotranspiration
(~450 mm)Evapotranspiration
(~450 mm)
Runoff of Surface Water (~250 mm)Runoff of Surface Water (~250 mm)
DecadesDecades
2424
The Basic Math of Water in the Upper BowThe Basic Math of Water in the Upper Bow Annual Annual AnnualAnnual
Precipitation but Rain falls in Intense StormsPrecipitation but Rain falls in Intense Storms
Precipitation (~780 mm)Precipitation (~780 mm)
Evapotranspiration
(~450 mm)Evapotranspiration
(~450 mm)
Runoff of Surface Water (~250 mm)Runoff of Surface Water (~250 mm)
Year to YearYear to Year
Runoff of Surface Water (~450 mm)Runoff of Surface Water (~450 mm)
Evapotranspiration
(~250 mm)Evapotranspiration
(~250 mm)
2525
Monthly Precipitation and Temperature at CalgaryMonthly Precipitation and Temperature at Calgary Source: Environment CanadaSource: Environment Canada
2626
Much of the Winter Precipitation Much of the Winter Precipitation Accumulates as SnowpackAccumulates as Snowpack
2727
Average Pattern of Snowpack Accumulation and LossAverage Pattern of Snowpack Accumulation and Loss Source: Environment CanadaSource: Environment Canada
High
Rainfall
Events
Possible
High
Rainfall
Events
Possible
Under
Climate
Change
Scenarios,
High Rainfall
Events Can
Occur Earlier
in the Spring
Under
Climate
Change
Scenarios,High Rainfall
Events Can
Occur Earlier
in the Spring
2828
HowHow’’s the Snowpack this year?s the Snowpack this year? Source: Alberta Environment, AESRDSource: Alberta Environment, AESRD
2013 Snowpack2014 Snowpack
2929
Flow Rates of the 2013 Bow River at CalgaryFlow Rates of the 2013 Bow River at Calgary Source: Alberta Environment, AESRDSource: Alberta Environment, AESRD
Average Peak of ~200 cmsIn 2013, peaked at ~1740 cms
3030
We have been there many times in the pastWe have been there many times in the pastWe will be there many times moreWe will be there many times more
Source. Various Historical Archives in AlbertaSource. Various Historical Archives in Alberta
3131
June 2013June 2013 A Very Large and A Very Large and
Concentrated Concentrated Precipitation EventPrecipitation Event
3232
Rainfall Intensity and River VolumeRainfall Intensity and River Volume
Time
RiverDischargeRate
Extended Bout of RainfallOver a 1 Week Period
A Short and Intensive RainfallEvent of a 2 –Day Period
3535
The Steep Elevation Loss of the Elbow River Headwaters.The Steep Elevation Loss of the Elbow River Headwaters.Source: Elbow River Basin ALCES SimulatorSource: Elbow River Basin ALCES Simulator
West East
South
North
3636
The Steep Elevation Loss of the Bow Basin Headwaters.The Steep Elevation Loss of the Bow Basin Headwaters.Source: Elbow River Basin ALCES SimulatorSource: Elbow River Basin ALCES Simulator
Bragg
Creek
Bragg
Creek
CalgaryCalgary
mass x slope (velocity) = energy
West
East
South
North
3737
The Steep Elevation Loss of the Elbow River Headwaters.The Steep Elevation Loss of the Elbow River Headwaters.Source: ALCES OnlineSource: ALCES Online
3838
The The ErosionalErosional
Power of FloodsPower of Floods Source: Calgary HeraldSource: Calgary Herald
3939
Some Math behind the Bow River Flood EventSome Math behind the Bow River Flood Event
Variable Amount Units
4040
Under the pull of Gravity, much of this precipitation Under the pull of Gravity, much of this precipitation will get to the will get to the MainstemMainstem
Rivers, and very quicklyRivers, and very quickly
4141
But the But the mainstemmainstem
river systems of the Bow River river systems of the Bow River basin only amount to about basin only amount to about ¾¾
of 1% of the landscape.of 1% of the landscape.
4242
The Elbow Dissipating EnergyThe Elbow Dissipating Energy Source: Rick Source: Rick BodanBodan, , Workabove.comWorkabove.com
4343
The Elbow River and Dissipating EnergyThe Elbow River and Dissipating Energy Source: Rick Source: Rick BodanBodan, , Workabove.comWorkabove.com
4444
Bow River Basin Reservoir InfrastructureBow River Basin Reservoir Infrastructure Considerable water can be retained but primary historical purposConsiderable water can be retained but primary historical purpose has e has
been electricity generation, not flood mitigationbeen electricity generation, not flood mitigation
Minnewanka157 M m3
U. Kananaskis93 M m3
Ghost50 M m3
Glenmore25 M m3Spray
199 M m3
Bearspaw,6 M m3
Barrier,21 M m3
L.
Kananaskis58 M m3
• Most topographically suitable sites for reservoirs have already been used
• Water storage capacity is continually reduced by sedimentation
Name of ReservoirWorking Volume of Water m3
4545
High Precipitation+
Concentrated Precipitation+
High Snowpack+
Low Landscape Resiliency=
High Water (Flood)
Contributing Factors to FloodsContributing Factors to Floods
4646
High Precipitation+
Concentrated Precipitation+
High Snowpack+
Low Landscape Resiliency+
Floodplain and Floodway Infrastructure=
High Water (Flood) and Economic Hardship
Contributing Factors to Flood DisastersContributing Factors to Flood Disasters
4747
Night Time Light EmissionNight Time Light Emission Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
4848
Footprint Area of the Energy SectorFootprint Area of the Energy Sector Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
~90 km2
4949
Footprint Area of the Forest SectorFootprint Area of the Forest Sector Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
~40 km2
5050
Footprint Area of the Road SectorFootprint Area of the Road Sector Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
~250 km2
5151
Footprint Area of the Residential SectorFootprint Area of the Residential Sector Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
~900 km2
5252
Footprint Area of the Agriculture SectorFootprint Area of the Agriculture Sector Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
~2,500 km2
5353
Footprint Area of All Land UsesFootprint Area of All Land Uses Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
~3,700 km2
5454
Land Use Footprint IntensityLand Use Footprint Intensity Source: Bow River Basin Source: Bow River Basin AlcesAlces
OnlineOnline
3,700 km2
= 24%15,500 km2
2014
5,200 km2
= 34%15,500 km2
2064
Footprint km2
= %Study Area km2
Year
5656
Holding Back the Water; Slowing its SpeedHolding Back the Water; Slowing its Speed Photo Credit: Jenny EarlePhoto Credit: Jenny Earle
5757
The The Role of Wetlands in Flood MitigationRole of Wetlands in Flood Mitigation Source: Source: MitschMitsch
and and GosselinkGosselink))
6060
Time Series of Natural Area in Upper BowTime Series of Natural Area in Upper Bow Source: East Slopes ALCES SimulatorSource: East Slopes ALCES Simulator
Pre‐Industrial 2010
2060
6262
Land Use and Flashy RunoffLand Use and Flashy Runoff
In comparison to natural ecosystems, roads,
settlements, acreages, cutblocks, croplands,
pasturelands, and industrial features generally
increase the pace (rate) at which precipitation runs off
landscapes.
6464
The Rivers of the Bow The Rivers of the Bow Basin are trying to Basin are trying to
release their flood release their flood energy into the energy into the
floodplain by scouring floodplain by scouring and depositingand depositing
We are trying to We are trying to concentrate its energy concentrate its energy
by containing it within by containing it within narrow and narrow and
constrained channels constrained channels
6666
Flooding in High RiverFlooding in High River Source: Source: www.outdoorsmenforum.cawww.outdoorsmenforum.ca
6767
Holding Back WaterHolding Back WaterResilient Natural SystemsResilient Natural Systems Engineering SolutionsEngineering Solutions
Optimal and Cost‐Effective Flood Mitigation Strategies require both of these
approaches to work in concert
6868
Moving beyond SilosMoving beyond Silos We need an Integrated Resource Management ParadigmWe need an Integrated Resource Management Paradigm
Forestry
Energy
Crop
s
Livestock
Reside
ntial
Mining
Reservoirs
Tran
sportatio
n
In practice, the watershed is fully integrated
Unfortunately, our watershed management principles
are still based on Silos
The volume and flow of its water reflects the full suite
of natural processes (climate) and landuses
6969
Summary ThoughtsSummary Thoughts• Precipitation is, by nature, highly variable in time (seasons, years, decades)
• Floods are a natural, and required, process for all healthy watersheds
• Climate Change models suggest that variation in precipitation (floods, droughts)
will increase in frequency and intensity
• The resiliency of the Bow River Watershed to absorb and hold meltwater
has been
impaired by land uses (forestry, agriculture, transportation, residential)
• Human infrastructure (crops, forestry, residential, transportation) has accelerated
the rate of water movement to mainstem
rivers
• We have intentionally constructed many billions of $ of infrastructure in the flood
plain of the Bow River Basin mainstem
rivers and its tributaries
• Although engineering solutions play a key role in flood mitigation, longterm
and
sustainable solutions to flood risk must incorporate a landscape
(watershed) level
• We should be looking for silver buckshot, not a silver bullet. We are all part of both
the problem and the solution.
7070
What Can We Do Now to Mitigate Flood Risk?What Can We Do Now to Mitigate Flood Risk?1.
Where possible, remove high‐risk infrastructure from the flood
plain
2.
Stop approving and building new infrastructure in the flood plain
3.
Relocate (elevate) valuables and key utilities (furnaces, water heaters, electrical controls) from basements;
4.
Restore natural river function and flow
5.
Promote the reconstruction of wetlands and riparian function
6.
Promote forestry practices (and other land uses) that encourage water retention in the headwater forest ecosystems
7.
Require, and support, regional planning initiatives that promote resilient watersheds