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OWWA/WEAO Joint Climate Change Committee
Climate Change and Infrastructure Design
Hitting a Moving Target
Infrastructure R...
Crystal Ball or Rear View Mirror
What do you really need for extreme
weather adaption?
2
If “Weather Zoltar” Predicted Future IDF,
… does it make a ‘BIG’ difference to your
adaptation priorities ?
If I had a
Wea...
We have always had flooding
Engineers don’t let that stop them in
in their quests …
4
Is predicting future weather a priority ?
Or understanding existing risks?
(like repeated operational ones)
http://http://...
Toronto Island flooding a new normal ?
Or an old extreme ?
2017 1973
6
data shows mostly an old extreme
http://www.cityfloodmap.com/2017/09/toronto-island-flooding-2017-were-lake.html
74
74.2
7...
Do roadways and basements flood due to
climate change factors ?
Or old intrinsic design limitations?
2017 1962
8
Climate Change or ‘Hydrology Change’?
http://www.cityfloodmap.com/2016/03/lost-rivers-newtonbrook-tributary.html 9
Climate Change or ‘Hydrology Change’?
http://www.cityfloodmap.com/2016/03/lost-rivers-newtonbrook-tributary.html 10
Hydraulic Design Limitations
‘Lost Rivers’ = 3x more insurance claims
http://www.cityfloodmap.com/2016/03/lost-rivers-newt...
Hydraulic Design Limitations
‘Lost Rivers’ = 3x more insurance claims
http://www.cityfloodmap.com/2016/03/lost-rivers-newt...
Higher Imperviousness
= Higher Runoff Risks
http://www.cityfloodmap.com/2016/08/urbanization-and-runoff-explain.html
13
Expanded Urban Areas (Pink)
… +1000 % in Rouge Watershed since 60’s
http://www.cityfloodmap.com/2016/08/land-use-change-dr...
Expanded Urban Areas (Pink)
… +1000 % in Rouge Watershed since 60’s
http://www.cityfloodmap.com/2016/08/land-use-change-dr...
Expanded Urban Areas (Pink)
… +1000 % in Rouge Watershed since 60’s
http://www.cityfloodmap.com/2016/08/land-use-change-dr...
Expanded Urban Areas (Pink)
… +1000 % in Rouge Watershed since 60’s
http://www.cityfloodmap.com/2016/08/land-use-change-dr...
Expanded Urban Areas (Pink)
… +1000 % in Rouge Watershed since 60’s
http://www.cityfloodmap.com/2016/08/land-use-change-dr...
Urban ‘Pink Splat’… like Cat in the Hat
… don’t think we’ll get
old hydrology back. 19
Given known design limitations
and significant, quantifiable
hydrology stresses affecting
urban flooding ….
20
.. should we “Blame it on the Rain”
like Milli Vanilli did ? 21
or critically assess local rain data trends?
http://www.cityfloodmap.com/2015/12/trends-in-canadian-shortduration.html
22
… but “What about 2005 & 2013…” ?
… the storms were extreme !”
Finch 2005
Ferarri 2013
23
2013 was a record for all “July 8’s”
.. but we do not design infrastructure
for particular calendar days.
20
40
60
80
100
...
… but “IBC says 40 year storms are
happening every 6 years !!!!!!!!!”
… is an “Insurance Fact”! 25
Telling the Weather Story - Gordon McBean - Empire Club presentation - YouTube
http://www.slideshare.net/RobertMuir3/storm...
Test : Infographics or Data
… can you tell the difference?
Environmental Commissioner
Engineering Climate Datasets v2.3
27
Southern ON Extreme Rain Trends Decreasing
http://www.cityfloodmap.com/2016/01/climate-change-ontario-short-duration.html
...
Toronto IDF Intensities Decreasing
• As annual
maximum values
drop, extreme
IDF intensities
decrease too.
• Toronto City
“...
Mississauga IDF Intensities Decreasing
• Mississauga
Airport 5-15
min. intensities
decreasing for
all return
periods.
• 24...
Southern ON Extreme Rain Trends Decreasing
http://www.cityfloodmap.com/2017/11/less-extreme-short-duration-rainfall-in.htm...
Canada-wide “lack of a detectable trend
signal”, some regional decreases.
http://www.tandfonline.com/doi/abs/10.1080/07055...
“Rear View Mirror”
data says:
Old standards were
sometimes a ‘wreck’
Hydrology changes
have ‘monster’ impact
Rain intensit...
Has rainfall increased with temperatures?
.. no, research at MIT/Columbia and U.
of Western show some opposite trends.
htt...
What and where do we need to adapt
for tomorrow’s expected extremes?
… same as for “design standard
adaptation” for yester...
• Toronto flood density varies
according to design
standards / age of servicing,
“CSO relief”.
• Overland risks increase
b...
Cities must focus on areas with overland flow limitations
too (these drive many flood reports and claims).
<- Not in these...
Why focus beyond valleys ?
… because flood records show this is the priority.
https://www.slideshare.net/RobertMuir3/urban...
August 19, 2005 Storm - Percentage of
Properties Flooded
Markham Adaptation Priorities are Pre 1980’s Areas
Pre 1980
1.0 %...
July 16, 2017 Storm - Percentage of
Properties Flooded
July 2017 Storm Confirmed Design Standard
Adaptation Priorities
Pre...
Future IDF ‘Stress Test’ – City-wide Sanitary System
• Future U. of R. A1B 50%
2065-2095 scenario.
• Chicago Storm -
incre...
Fully-Separated Sanitary (post 1980’s)
Not Stressed with Future IDF (High Resiliency)
Shallow Sewer (limited freeboard for...
0
50
100
150
200
250
300
0 50 100 150 200 250 300 350 400 450 500
RainfallIntensity(mm/hr)
Time (minutes)
Markham Storm (3...
What is the role of knowing the
future ?
44
Markham Class EA Future Adaptation Requirements
200
210
220
230
240
250
260
270
280
290
300
1975 1995 2015 2035 2055 2075 ...
Markham Class EA Future Adaptation Requirements
200
210
220
230
240
250
260
270
280
290
300
1975 1995 2015 2035 2055 2075 ...
Future IDF is a Moving Target
200
210
220
230
240
250
260
270
280
290
300
1975 1995 2015 2035 2055 2075 2095
Buttonville
A...
0
50
100
150
200
250
300
350
400
1975 1995 2015 2035 2055 2075 2095
Post 80’s systems are
resilient for 20 – 30 %
higher I...
Conclusions
• There are significant industry gaps in understanding:
• Past extreme rainfall trends (decreasing in southern...
Thank You
Questions ?
More Rob :
Blog: www.CityFloodMap.com
Podcast: Open During Construction on iTunes
Twitter: @RobertMu...
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Infrastructure Resiliency and Adaptation for Climate Change and Today’s Extremes

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OWWA/WEAO Joint Climate Change Committee Seminar, Climate Change and Infrastructure Design, Hitting a Moving Target, Mississauga, Ontario, November 16, 2017

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Infrastructure Resiliency and Adaptation for Climate Change and Today’s Extremes

  1. 1. OWWA/WEAO Joint Climate Change Committee Climate Change and Infrastructure Design Hitting a Moving Target Infrastructure Resiliency and Adaptation for Climate Change and Today’s Extremes Robert J. Muir, M.A.Sc., P.Eng. Manager, Stormwater City of Markham November 16, 2017 - Mississauga, Ontario 1
  2. 2. Crystal Ball or Rear View Mirror What do you really need for extreme weather adaption? 2
  3. 3. If “Weather Zoltar” Predicted Future IDF, … does it make a ‘BIG’ difference to your adaptation priorities ? If I had a Weather oltar – short Story. 3
  4. 4. We have always had flooding Engineers don’t let that stop them in in their quests … 4
  5. 5. Is predicting future weather a priority ? Or understanding existing risks? (like repeated operational ones) http://http://www.cityfloodmap.com/2015/12/toronto-go-train-flood-avoidable-july-8.html 5
  6. 6. Toronto Island flooding a new normal ? Or an old extreme ? 2017 1973 6
  7. 7. data shows mostly an old extreme http://www.cityfloodmap.com/2017/09/toronto-island-flooding-2017-were-lake.html 74 74.2 74.4 74.6 74.8 75 75.2 75.4 75.6 75.8 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005 2015 MonthlyLevel(m) Year Lake Ontario Historical May - August Levels May Average August Average Source: 1918-2016 http://www.tides.gc.ca/C&A/network_means-eng.html 2017 http://tides-marees.gc.ca/C&A/pdf/Bulletin1708.pdf May 5 cm above record August not a record 7
  8. 8. Do roadways and basements flood due to climate change factors ? Or old intrinsic design limitations? 2017 1962 8
  9. 9. Climate Change or ‘Hydrology Change’? http://www.cityfloodmap.com/2016/03/lost-rivers-newtonbrook-tributary.html 9
  10. 10. Climate Change or ‘Hydrology Change’? http://www.cityfloodmap.com/2016/03/lost-rivers-newtonbrook-tributary.html 10
  11. 11. Hydraulic Design Limitations ‘Lost Rivers’ = 3x more insurance claims http://www.cityfloodmap.com/2016/03/lost-rivers-newtonbrook-tributary.html 11
  12. 12. Hydraulic Design Limitations ‘Lost Rivers’ = 3x more insurance claims http://www.cityfloodmap.com/2016/03/lost-rivers-newtonbrook-tributary.html 12
  13. 13. Higher Imperviousness = Higher Runoff Risks http://www.cityfloodmap.com/2016/08/urbanization-and-runoff-explain.html 13
  14. 14. Expanded Urban Areas (Pink) … +1000 % in Rouge Watershed since 60’s http://www.cityfloodmap.com/2016/08/land-use-change-drives-urban-flood-risk.html 14
  15. 15. Expanded Urban Areas (Pink) … +1000 % in Rouge Watershed since 60’s http://www.cityfloodmap.com/2016/08/land-use-change-drives-urban-flood-risk.html 15
  16. 16. Expanded Urban Areas (Pink) … +1000 % in Rouge Watershed since 60’s http://www.cityfloodmap.com/2016/08/land-use-change-drives-urban-flood-risk.html 16
  17. 17. Expanded Urban Areas (Pink) … +1000 % in Rouge Watershed since 60’s http://www.cityfloodmap.com/2016/08/land-use-change-drives-urban-flood-risk.html 17
  18. 18. Expanded Urban Areas (Pink) … +1000 % in Rouge Watershed since 60’s http://www.cityfloodmap.com/2016/08/land-use-change-drives-urban-flood-risk.html 18
  19. 19. Urban ‘Pink Splat’… like Cat in the Hat … don’t think we’ll get old hydrology back. 19
  20. 20. Given known design limitations and significant, quantifiable hydrology stresses affecting urban flooding …. 20
  21. 21. .. should we “Blame it on the Rain” like Milli Vanilli did ? 21
  22. 22. or critically assess local rain data trends? http://www.cityfloodmap.com/2015/12/trends-in-canadian-shortduration.html 22
  23. 23. … but “What about 2005 & 2013…” ? … the storms were extreme !” Finch 2005 Ferarri 2013 23
  24. 24. 2013 was a record for all “July 8’s” .. but we do not design infrastructure for particular calendar days. 20 40 60 80 100 120 140 1945 1955 1965 1975 1985 1995 2005 2015 2025 MaximumRainfallDepth(mm) Pearson Airport Maximum Daily Rainfall 1950 - 2016 http://www.cityfloodmap.com/2016/01/toronto-climate-change-extreme-rainfall.html http://www.cityfloodmap.com/2015/11/thinking-fast-and-slow-about-extreme.html 24
  25. 25. … but “IBC says 40 year storms are happening every 6 years !!!!!!!!!” … is an “Insurance Fact”! 25
  26. 26. Telling the Weather Story - Gordon McBean - Empire Club presentation - YouTube http://www.slideshare.net/RobertMuir3/storm-intensity-not-increasing-factual-review-of-engineering-datasets Actually, not a fact … .. confused prediction with past data. 26
  27. 27. Test : Infographics or Data … can you tell the difference? Environmental Commissioner Engineering Climate Datasets v2.3 27
  28. 28. Southern ON Extreme Rain Trends Decreasing http://www.cityfloodmap.com/2016/01/climate-change-ontario-short-duration.html Significant Decr. Decrease Increase Significant Incr. Source: Environment Canada Engineering Climate Dataset ftp://ftp.tor.ec.gc.ca/Pub/Engineering_Climate_Dataset/IDF/ Idf_v2-3_2014_12_21_trends.txt in IDF_Additional_Additionnel_v2.30.zip 28
  29. 29. Toronto IDF Intensities Decreasing • As annual maximum values drop, extreme IDF intensities decrease too. • Toronto City “Bloor Street” trends are lower for all durations and for all return periods. http://www.cityfloodmap.com/2016/01/toronto-climate-change-extreme-rainfall.html www.cityfloodmap.com Source: Environment Canada Engineering Climate Dataset ftp://ftp.tor.ec.gc.ca/Pub/Engineering_Climate_Dataset/IDF/ Up to 2007 per Dataset v2.3, to 2003 per Dataset v1, to 1990 per hardcopy records CityFloodMap.Com, 2016 29
  30. 30. Mississauga IDF Intensities Decreasing • Mississauga Airport 5-15 min. intensities decreasing for all return periods. • 24 hour trends are downward despite July 8, 2013 storm. 30
  31. 31. Southern ON Extreme Rain Trends Decreasing http://www.cityfloodmap.com/2017/11/less-extreme-short-duration-rainfall-in.html 31 http://www.cityfloodmap.com/2017/09/less-extreme-ontario-rainfall.html http://guelph.ca/wp-content/uploads/SMMP-Appendix_E_Combined_IDF_Report.pdf https://drive.google.com/open?id=1Gxmg8gtkzZuv-ZqiqYpc3tQ9r-Ie1v1p
  32. 32. Canada-wide “lack of a detectable trend signal”, some regional decreases. http://www.tandfonline.com/doi/abs/10.1080/07055900.2014.969677?journalCode=tato20 32
  33. 33. “Rear View Mirror” data says: Old standards were sometimes a ‘wreck’ Hydrology changes have ‘monster’ impact Rain intensity change was a ‘yappy puppy’ 33
  34. 34. Has rainfall increased with temperatures? .. no, research at MIT/Columbia and U. of Western show some opposite trends. http://www.ldeo.columbia.edu/~clepore/publications_pdf/grl52319.pdf https://www.slideshare.net/glennmcgillivray/iclr-friday-forum-updating-idf-curves-for-future-climate-march-24-2017 Decreases above 5 degrees C. Clausius-Clapeyron theory has not been observed. ‘Flat’ trends compared to theory. http://www.cityfloodmap.com/2017/06/does-higher-temperature-increase-rain.html 34
  35. 35. What and where do we need to adapt for tomorrow’s expected extremes? … same as for “design standard adaptation” for yesterday’s & today’s extremes. 35
  36. 36. • Toronto flood density varies according to design standards / age of servicing, “CSO relief”. • Overland risks increase basement back-up risks. Toronto Adaptation Priority is Old Partially Separated Sewer Service Areas – increased capacity needed. Toronto Basement Flood Reports May 2000, August 2005, July 2013 & Age of Watermain Construction (Estimated Era of Drainage Design Standards) © CityFloodMap.com 36
  37. 37. Cities must focus on areas with overland flow limitations too (these drive many flood reports and claims). <- Not in these areas …. … but in these overland flow issue areas beyond valleys. 37
  38. 38. Why focus beyond valleys ? … because flood records show this is the priority. https://www.slideshare.net/RobertMuir3/urban-flood-risk-from-flood-plains-to-floor-drains 38
  39. 39. August 19, 2005 Storm - Percentage of Properties Flooded Markham Adaptation Priorities are Pre 1980’s Areas Pre 1980 1.0 % Flooded Post 1980 0.15 % Flooded * Considers all properties city-wide (storm intensity was high across the majority of the City). Standard Adaptation: downspout disconnection, MH sealing, storm capacity upgrades (limit sanitary inflows), backwater valves, etc. 39
  40. 40. July 16, 2017 Storm - Percentage of Properties Flooded July 2017 Storm Confirmed Design Standard Adaptation Priorities Pre 1980 2.4 % Flooded 1980 - 1990 0.6% Flooded Post 1990 0.04% Flooded • Considers north-east quadrant of the City where the storm intensities were highest (25,527 properties). Post-1990 servicing flooded 7 of 15,889; 1980-1900 servicing flooded 21 of 3366; pre-1980 servicing flooded 151 of 6272. Most effective to focus on these old areas – new ones are resilient to 2095. See CWWA 2017 future stress test analyses. 40
  41. 41. Future IDF ‘Stress Test’ – City-wide Sanitary System • Future U. of R. A1B 50% 2065-2095 scenario. • Chicago Storm - increase IDF values by 30% over 2 hrs. • Use calibrated /monitored values. • Apply calibrated inflow & infiltration response. • Dynamic / gradually varied flow model (InfoWorks). • Sanitary system HGL less than 2.0 m below grade (near basement). IDF Data Hyetograph Selection Dry Weather Sanitary Flow I&I Transformation (Extraneous Flow) Hydraulic Performance / Freeboard Damages / Risk – Assess Need for Adaptation Today’s IDF Future IDF Sewer Surcharge (%) 7.4 12.1 + 64 % MH Surcharge (%) 1.8 3.5 + 94% Impacts in old subdivisions, new subdivisions resilient Most Critical ± 2000 % Risk Less Critical 41
  42. 42. Fully-Separated Sanitary (post 1980’s) Not Stressed with Future IDF (High Resiliency) Shallow Sewer (limited freeboard for dry weather) Existing 100-Year IDF - MH Freeboard < 2 m Future 100-Year IDF – MH Freeboard <2 mToday’s IDF Future IDF Freeboard < 2 m = Back-up Risk Impacts in old subdivisions with existing limitations Pre 1980 80’s 90’s 42
  43. 43. 0 50 100 150 200 250 300 0 50 100 150 200 250 300 350 400 450 500 RainfallIntensity(mm/hr) Time (minutes) Markham Storm (3 Hr AES) 100 Year TRCA Storm (AES 12 Hr) 100 Year 100-Year Storm Hyetographs Are Highly Variable / Uncertain Risk “Gap” Sanitary sewer surcharge and flood risk vary by 2000% based on changes in storm pattern. 43
  44. 44. What is the role of knowing the future ? 44
  45. 45. Markham Class EA Future Adaptation Requirements 200 210 220 230 240 250 260 270 280 290 300 1975 1995 2015 2035 2055 2075 2095 45 Buttonville Airport (Markham) Pearson Airport (Mississauga) Observed Bloor Street (Toronto) Markham Design Standard RainIntensitymm/hr(5minute100-year)
  46. 46. Markham Class EA Future Adaptation Requirements 200 210 220 230 240 250 260 270 280 290 300 1975 1995 2015 2035 2055 2075 2095 Buttonville Airport (Markham) Pearson Airport (Mississauga) Observed Bloor Street (Toronto) Predicted Markham Design Standard Future Safety Factors Future Stress Test RainIntensitymm/hr(5minute100-year) 46
  47. 47. Future IDF is a Moving Target 200 210 220 230 240 250 260 270 280 290 300 1975 1995 2015 2035 2055 2075 2095 Buttonville Airport (Markham) Pearson Airport (Mississauga) Observed Bloor Street (Toronto) Predicted Markham Design Standard RainIntensitymm/hr(5minute100-year) 47
  48. 48. 0 50 100 150 200 250 300 350 400 1975 1995 2015 2035 2055 2075 2095 Post 80’s systems are resilient for 20 – 30 % higher IDF (storm & sanitary networks) So focus on known problems & priorities to adapt Observed Predicted Today’s Standard RainIntensitymm/hr(5minute100-year) “Design Standard Adaptation” in old areas. Requires 250% or more conveyance capacity.Pre 80’s Standard 48
  49. 49. Conclusions • There are significant industry gaps in understanding: • Past extreme rainfall trends (decreasing in southern Ontario) • Key quantifiable drivers for flood risk reduction weather vs. hydrology change weather vs. hydraulics constraints (overland design) • System vulnerability varies with design standards: • Post 1990 standards significantly decreased flood risk to 1/60th of pre-1980’s standards risks. • Historical land use practices with limited design standards drive specific, local adaptation priorities (no generic fixes). • “Design Standard Adaptation” adds resiliency • Addressing older system limitations provides future climate adaptation co-benefit … regardless of future rainfall IDF (uncertain & not converging). • Highest incremental benefits for infrastructure improvements to older systems – marginal benefits decrease at higher levels.49
  50. 50. Thank You Questions ? More Rob : Blog: www.CityFloodMap.com Podcast: Open During Construction on iTunes Twitter: @RobertMuir_PEng More City of Markham : Web: www.markham.ca Twitter: @CityofMarkham 50

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