11
Natural Hazards Mitigation on Natural Hazards Mitigation on Fitzsimmons Creek, Whistler BCFitzsimmons Creek, Whistler BC
James Hallisey, RMOWJames Hallisey, RMOWMike V. Currie & David Roche, KWLMike V. Currie & David Roche, KWL
Presenters:Presenters:
22
Welcome to the MountainsWelcome to the Mountains
BeautyBeauty…… ……and the beastand the beast
33
GeohazardsGeohazards in BCin BC
Incr
easi
ng S
edim
ent
Decreasing Water
Incr
easi
ng V
eloc
ity
44Kamloops, 1972Kamloops, 1972
GeohazardsGeohazards in BC in BC -- FloodsFloods
55
Britannia Creek, 1991Britannia Creek, 1991
GeohazardsGeohazards in BC in BC –– Debris FloodsDebris Floods
66
GeohazardsGeohazards in BC in BC –– Debris FloodsDebris Floods
77
GeohazardsGeohazards in BC in BC –– Debris FlowsDebris Flows
Lions Bay, 1983Lions Bay, 1983
88
GeohazardsGeohazards in BC in BC –– Debris FlowsDebris Flows
Lions Bay, 1983Lions Bay, 1983
99
GeohazardsGeohazards in BC in BC –– LandslidesLandslides
North Van, 2005North Van, 2005
1010
GeohazardsGeohazards in BC in BC –– RockfallRockfall
Sea to Sky Highway, 2008
1111
Contrasting Creek ProcessesContrasting Creek Processes
Mitigation ProjectsMitigation Projects
Design StandardDesign Standard
Relative FrequencyRelative Frequency
Debris Floods & Debris Floods & Debris FlowsDebris Flows
ClearClear--Water Water FloodsFloods
Mitigation ProjectsMitigation Projects
Design StandardDesign Standard
ImpactImpact
Relative FrequencyRelative Frequency
Debris Floods & Debris Floods & Debris FlowsDebris Flows
ClearClear--Water Water FloodsFloods
RareRareCommonCommon
SevereSevereVariableVariable
RareRareOftenOften
1212
Decision MakerDecision Maker’’s Considerationss Considerations
What is the nature of the hazard? What is the nature of the hazard?
AVOID hazards with land use zoning!AVOID hazards with land use zoning!
Best approach to further reduce hazard?Best approach to further reduce hazard?
Who will own, operate and maintain?Who will own, operate and maintain?
Environmental implications?Environmental implications?
HOW SAFE IS HOW SAFE IS ““SAFESAFE””??????
Be aware of residual risk!Be aware of residual risk!
1313
A Village by the CreekA Village by the Creek
Fitzsimmons Creek
Whistler Village
Bus Loop
Training Berm
Day Skier Lots
Conference Centre
1414
1991 Debris Flood Event1991 Debris Flood Event
August 30, 1991 August 30, 1991 –– not flood seasonnot flood season
Debris deposition up to 2 m deepDebris deposition up to 2 m deep
Boulders up to 1 m in sizeBoulders up to 1 m in size
Hundreds of trees up to 50 m longHundreds of trees up to 50 m long
Vehicle & skier bridges washed outVehicle & skier bridges washed out
1515
1991 Debris Flood Event1991 Debris Flood Event
Bed Level after floodBed Level after flood
Photo taken June 1991
1616
Fitzsimmons Glacier
Watershed Watershed GeohazardsGeohazards TourTour
1717
Fitzsimmons Glacier
Fitzsimmons SlumpFitzsimmons Slump
Singing Pass TrailSinging Pass Trail
Watershed Watershed GeohazardsGeohazards TourTour
1818
Whistler VillageWhistler Village
Watershed Watershed GeohazardsGeohazards TourTour
PumphousePumphouse SlideSlide
1919
RMOW Mitigation ProgramRMOW Mitigation Program
Day Skier Lots Day Skier Lots & Training & Training BermBerm
Fitz CreekFitz CreekVillageVillage
2020
RMOW Mitigation Program contRMOW Mitigation Program cont’’dd
Village Village FloodwaysFloodways
2121
Structural Floodproofing
RMOW Mitigation Program contRMOW Mitigation Program cont’’dd
2222
RMOW Mitigation Program contRMOW Mitigation Program cont’’dd
Gravel Removals
2323
Funding Funding MitigativeMitigative WorksWorks
Developers build most worksDevelopers build most works
RMOW assumes O&M responsibility RMOW assumes O&M responsibility
Trying to fund debris barrier for Trying to fund debris barrier for years years -- creative solution requiredcreative solution required
2424
Funding the BarrierFunding the Barrier
RMOW acquired day skier lots from RMOW acquired day skier lots from Province of BCProvince of BC
RMOW agrees to construct debris RMOW agrees to construct debris barrier prior to 2010 Olympicsbarrier prior to 2010 Olympics
RMOW can charge for parking to RMOW can charge for parking to recover costsrecover costs
KWL team retained in 2007 for designKWL team retained in 2007 for design
2525
Defining the Design EventDefining the Design Event
KWL & team began pre-design in 2007
500-yr event volume up to 200,000 m³5 to 6 m high surge front1 m boulders moving at 5 m/s
2626
Flow
Location
Defining the GeometryDefining the Geometry
Geometry determines storage relationship
2727
Defining the GeometryDefining the Geometry
Debris Deposition Angle
0%
1%
2%
2828
Barrier Height SelectionBarrier Height Selection
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000 90,000 100,000 110,000 120,000 130,000 140,000 150,000
Stored Volume (m3)
Bar
rier H
eigh
t (m
)
714.0
715.0
716.0
717.0
718.0
719.0
720.0
721.0
722.0
723.0
724.0
725.0
726.0
727.0
728.0
729.0
730.0
Bar
rier E
leva
tion
(m a
sl)
HEI
GH
T
STORAGE VOLUME
2% Curve
8 m high34,000 m³ storage
Village
Bus LoopParking Lots
Berm
Barrier
2929
Barrier Design ConstraintsBarrier Design Constraints
Debris flood: unusual load combinationsDebris flood: unusual load combinations
Structural constraintsStructural constraints
Very, very weak rockVery, very weak rock
Tight site, creek crossing thru structureTight site, creek crossing thru structure
Fish habitatFish habitat
Short inShort in--stream construction windowstream construction window
Tight design & construction scheduleTight design & construction schedule
3030
Three continents, no winnersThree continents, no winners……
3131
Three continents, no winnersThree continents, no winners……
3232
Three continents, no winnersThree continents, no winners……
3333
Three continents, no winnersThree continents, no winners……
3434
Three continents, no winnersThree continents, no winners……
3535
Starting from ScratchStarting from Scratch
3636
Sept 2008
Overcoming ChallengesOvercoming Challenges……
3737
October 31, 2008 – start of flood season
Overcoming ChallengesOvercoming Challenges……
3838
October 31, 2008 – in-stream permit expires
Overcoming ChallengesOvercoming Challenges……
3939
Overcoming ChallengesOvercoming Challenges……
Winter demobilization, December 2008
4040
A New BeginningA New Beginning
4141
April 3
A New BeginningA New Beginning
4242
April 23
A New BeginningA New Beginning
4343
June 23
A New BeginningA New Beginning
4444
5 gal bucket5 gal bucket
End in Sight End in Sight –– October 2009October 2009
4545
End in Sight End in Sight –– October 2009October 2009
4646
2” Steel Plate
End in Sight End in Sight –– October 2009October 2009
4747
End in Sight End in Sight –– October 2009October 2009
4848
End in Sight End in Sight –– October 2009October 2009
4949
Final ProductFinal Product
Natural Materials
Wider, fish-passable channel
Removable fence for maintenance access
Abutment geometry slows and concentrates debris surge
Major event will overtop steel grillage
Earthfill has freeboard for 2,500 yr event
New GRS wall face for erosion protection
Monitoring Instrumentation
5050
Final ProductFinal Product
5151
Final ProductFinal Product
5252
Project ResultsProject Results
Completed on time in November 2009Completed on time in November 2009
Completed under budget, total capital Completed under budget, total capital cost $3.8Mcost $3.8M
RMOW has assumed O&M RMOW has assumed O&M responsibilityresponsibility
Recently won an Award of Merit from Recently won an Award of Merit from the Consulting Engineers of BCthe Consulting Engineers of BC
5353
AcknowledgmentsAcknowledgments
Lead ContractorsCoastal Mountain Excavations – Access Road
Creekside Resources Inc – Debris Barrier Site Works Murray Latta Progressive Machine Inc. – Structural Steel
Resort Municipality of WhistlerJames Hallisey
Brian Barnett
BGC EngineeringWayne SavignyMark PritchardMatthias Jakob
Alex StrouthHamish Weatherly
Lukas ArensonScott McDougall
Cascade EnvironmentalDave WilliamsonJanvier Doire
Gygax Engineering AssociatesAdrian GygaxAndrew Pauli
Kerr Wood Leidal AssociatesMike CurrieDave RocheJason MillerTabe Johnson
5454
Questions?Questions?