MANITOBA FLOOD PROTECTION PROJECTS Project Justification and Benefits. Science Imagination Collaboration

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Giles Quinn
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1 MANITOBA FLOOD PROTECTION PROJECTS Project Justification and Benefits Science Imagination Collaboration

2 Presentation Outline Extreme events on Red and Assiniboine Manitoba Flood Protection Works KGS Group Flood Experience 1950 Red River Flood and Response 1997 Red River Flood and Response 2009 Protection Benefits 2011 and 2014 AR and Lake MB Basin

1950 Red River Flood and Response 1997 Red River Flood and

3 Acknowledgements Manitoba Infrastructure and Transportation Flood facts and data Royal Commission on Flood Cost- Benefit 1958 KGS Group project data with permission from MIT

4 Manitoba s Flood Control System Driven by major historic events! 200 Assiniboine River at Portage la Prairie 100 1:200 57,100 cfs 1:100 47,500 cfs Red River at James Ave 2011 & ,000 cfs ~ 140 year

5 Manitoba Flood Protection Works Shellmouth Dam L Manitoba & L St Martin Outlet Channels Assiniboine River Dikes Portage Diversion Red River Floodway Community Ring Dikes (18)

6 KGS Group Flood Control Project Experience Manitoba Floodway Expansion Red River Ring Dikes Assin R and L Mb Basin Concept Design L Manitoba and L St. Martin Channel Studies Advisory Services for the Fargo Floodway

Mb Basin Concept Design L Manitoba and L St.

7 Red River 1950 Flood Major flooding Winnipeg / Red River Valley. The Forks Red River peak at a record 30.2 feet at Winnipeg. 108,000 cfs natural flow Wpg 100,000 residents (one third of Winnipeg) evacuated. Morris Estimated that $125.5 million in damages (~$1 billion today) Led to Red River Floodway Floodway Studies

108,000 cfs natural flow Wpg 100,000 residents (one third of Winnipeg)

8 Red River Floodway Royal Commission on Flood Cost- Benefit 1958 Numerous options considered diversions, detention basins, reservoirs, channel improvements. Insert Graphic Plate 3

9 Benefit Cost Analysis Conventional Benefit Cost Assessment Damage Frequency Curve Expected Annual Damages Stage discharge Stage damage curve Frequency discharge Frequency damage curve Expected annual damages Benefits [ avoided damages] Compare to annual costs Alternate project evaluation

curve Frequency discharge Frequency damage curve Expected annual

10 Damages Estimate Damages - Buildings - Relocation - Infrastructure - Income loss - Flood fighting

11 Selection of 60,000 cfs Floodway $ 63 M B-C Ratio Incremental B-C Ratio Existing Conditions Benefits Flood Protection

12 Royal Commission Report Flood Protection Recommendations Implementation 1962 to 1972 Floodway 60,000 cfs Portage Division 25,000 cfs Shellmouth Dam 7,000 cfs Capacity 169,000 cfs [ 1:160 yr] $ 20.5 M $ 10.8 M

Red River 1997 Flood Most severe in Manitoba's Red River valley since 1852.

Rapid melt in mid-april. Crest at approximately 24.5 feet in Winnipeg.

13 Red River 1997 Flood Most severe in Manitoba's Red River valley since Total basin precipitation, 221 mm, >> norm of 130 mm April Colorado low - snowfall of 90 mm to the Valley. Rapid melt in mid-april. Crest at approximately 24.5 feet in Winnipeg. 160,000 cfs Natural in Winnipeg [ 100 yr flood in 97] Without the flood control works, the crest would have been 35 feet. An estimated 1,000 homes were damaged. Significant Damage upstream of Winnipeg

14 Depth of Flooding above Floor (ft) Floodway Expansion Economic Analysis Followed 1997 Flood Similar process to 1958 Damage estimates GIS Based Grand Forks Experience 100 % Damages - % Market Value Basement Floor Level DEM developed for City Depth of flooding Building damage function Tax assessment data base for COW [ geo-referenced]

Experience 100 % Damages - % Market Value Basement Floor Level DEM developed for

15 Floodway Expansion Benefits 700 year flood without Expansion 700 year flood with Expansion Basement Flooding Surface Flooding -Residential -Commercial / Institutional -Vehicles -Infrastructure -Transportation -Flood Fighting -Temp Relocation Income loss [largely excluded]

-Residential -Commercial / Institutional -Vehicles -Infrastructure

16 Expected Annual Damage (EAD) Conventional graphical method USACE HEC-FDA (Flood Damage Analysis) Incorporates uncertainty in flow probability, stagedischarge & stage-damage Monte-Carlo simulation => distribution and best estimate of EAD

uncertainty in flow probability, stagedischarge &

17 Cost & Damages (B $) Floodway Upgrade Capacity Optional Channels sizes assessed Capacity greater than 1:700 marginally more costly than benefits 1:700 yr

18 Expansion Components $ 700 M project 2005 to M m3

19 Red River 2009 Flood Fourth highest since Crest would have been 32.5 feet - downtown Wpg 128,000 cfs natural flow Wpg 40 yr Benefits Operation of the Red River Floodway, Portage Diversion and Shellmouth Reservoir Downtown Winnipeg the Forks Reduced the crest by 10 feet Approximately $10 billion in damages prevented

the Red River Floodway, Portage Diversion and Shellmouth Reservoir Downtown

20 Red River Flood Protection Benefits Since 1968 prevented more than $30 Billion flood damages in Winnipeg During the 2009 flood the ring dikes prevented about $700 Million in flood damages Morris

21 Assiniboine River and Lake Manitoba Basins 2011 & 2014 Floods - L Manitoba ~ 82,000 km2 Lake St Martin Qu Appelle R Assiniboine R~`162,000 km2 Souris R

22 Assiniboine and Lake Manitoba Basins 2011 Flood Highest water levels and flows in modern history across parts of Manitoba and Saskatchewan. Estimated to be at levels experienced once in 330 years. 140 years on the Lower Assiniboine Lake Manitoba, water levels with wind estimated to be 1:2,000 year event. Governments at all levels in excess of $1 billion on flood fighting and compensation (Environment Canada).

23 Assiniboine and Lake Manitoba Basins 2011 Flood Unprecedented flooding in 2011 Emergency outlet channel Lake St. Martin to Lake Winnipeg. Opened Nov. 1, 2011 to Nov 2012 July 2014 to Aug ,100 Manitobans displaced Implementation of LM and LSM Channels in progress

24 OPTIONS FOR FLOOD MITIGATION Study Areas and Flood Mitigation Alternatives - Community Dikes - Diversion Channels - Small Reservoirs - Large Reservoirs - Linear Dikes

25 Criteria for Project Selection 1:200 yr as recommended by the Manitoba 2011 Flood Review Task Force Report Flood of record Economic analysis Lower Assiniboine Recommendations based on 1:200 yr event

26 LOWER ASSINIBOINE RIVER VULNERABILITIES STUDY RECOMENDATIONS Regulated Flood Protection Level 1:200 year Flood Protection Infrastructure Note: Estimated Costs do not include Individual Flood Protection on Lake Manitoba. Proposed Capacity Preliminary Estimated Costs for Upgrade Provincial Assiniboine Dikes 23,100 cfs $273 Million Assiniboine River Baie St. Paul to Headingley 23,100 cfs $63 Million Portage Diversion 34,000 cfs $343 Million Lake Manitoba Outlet 7,500 cfs $230 Million Lake St. Martin Outlet 11,500 cfs $220 Million Total Estimated Cost $1,129 Million

27 Conclusions / Wrap-up Investments in Flood Protection in Manitoba paid back many times over Principals of Flood Benefit evaluation consistent over many decades Advances in GIS and data processing allow for more sophisticated assessments

28 Thank-You

Assiniboine River and Lake Manitoba Basins Flood Mitigation Study: Providing Greater Protection For Manitobans From Flood Risks

Assiniboine River and Lake Manitoba Basins Flood Mitigation Study: Providing Greater Protection For Manitobans From Flood Risks Welcome! Manitoba Infrastructure and Transportation is studying flooding