natural hazards mitigation on fitzsimmons creek, whistler … · natural hazards mitigation on...

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


1818

Whistler VillageWhistler Village


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


2222


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


3232


3333


3434


3535

Starting from ScratchStarting from Scratch

3636

Sept 2008

Overcoming ChallengesOvercoming Challenges……

3737

October 31, 2008 – start of flood season


3838

October 31, 2008 – in-stream permit expires


3939


Winter demobilization, December 2008

4040

A New BeginningA New Beginning

4141

April 3


4242

April 23


4343

June 23


4444

5 gal bucket5 gal bucket

End in Sight End in Sight –– October 2009October 2009

4545


4646

2” Steel Plate


4747


4848


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


5151


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?

natural hazards mitigation on fitzsimmons creek, whistler … · natural hazards mitigation on...

Documents