Radio-Canada Ombudsman Finds Standards Violations in Inaccurate Reporting on Extreme Rainfall Trends in Canada

Radio-Canada found one of their journalists has again violated the Journalistic Standards and Practices when reporting on historical extreme rainfall trends linked to climate change.  This is Ombudsman Guy Gendron's review in french:

https://cbc.radio-canada.ca/fr/ombudsman/revisions/2020-11-19

And here is the link to the english translation on that page:

https://site-cbc.radio-canada.ca/media/5702/review-robert-muir-november-19-2020-sw.pdf

The violation relates to Radio-Canada's standards for reporting accuracy and for handling corrections related to this story:

Climate change: Environment Canada confirms rain becomes more extreme, By Marc Montgomery, english@rcinet.ca Posted: Wednesday, June 3, 2020 13:27, Last Updated: Thursday, November 19, 2020 10:04

link: https://www.rcinet.ca/en/2020/06/03/climate-change-environment-canada-confirms-rain-and-weather-extremes/

The review is quite harsh.  The Ombudsman found errors in the original article and in the corrections to the article based on our complaint, and summed it up this way (my bold):

"When it comes to accuracy, the JSP expects us to “seek out the truth” and “invest our time and our skills to learn, understand and clearly explain the facts.” The article failed at all these levels. The article’s errors, omissions, imprecisions and inaccuracies are so numerous that I believe it is an aggravated case of failure to comply with the JSP. Since this seems to have been a repeat offence on the same subject by journalist Marc Montgomery, I cannot hold him solely responsible. This is also an issue of inadequate editorial oversight.

Given the scope of the observed failures, I doubt it is possible to correct an article that is so flawed through and through. If Radio Canada International decides to amend it, I strongly recommend that the task be assigned to another journalist, preferably someone who has demonstrated their ability to cover environmental topics.

Moreover, I think the problems encountered cannot be attributed to the complainant’s overly high expectations in terms of technical considerations that would be incomprehensible for average readers. News stories must simplify concepts that are sometimes complex, but without distorting the meaning."

In the thorough review, the Ombudsman checked the references that the journalist cited and found that the article distorted the meaning, misleading readers.  For example he wrote:

"All in all, I believe the article misleads readers with respect to ECCC’s position on the frequency and severity of rainfall events by implying that the study “confirms what many have been saying,” namely that rain “becomes more extreme,” at least as far as Canada is concerned."

He noted that the article had material that was "incongruous" and "awkward", and that corrections had lacked "transparency" and "humility" and one instance was deemed "false".  When describing the amount of errors associated with the documentation and attribution of corrections he wrote:

"It would be difficult to qualify all these errors, omissions, imprecisions and inaccuracies as having occurred merely by chance."

The Ombudsman seems to suggest that there are other factors, or perhaps motivations, that result in such extensive problems with the reporting.

Here is how the review concludes listing the shortcomings in meeting Radio-Canada journalistic standards:

"Here is a summary of the article’s main shortcomings:

The title is still problematic.

The choice of photos and the selected excerpts from the ECCC study imply that the title confirms an already observed increase in extreme weather events in Canada.

The juxtaposition of the citation from Blair Feltmate of the Intact Centre on Climate Adaptation – dating from 18 months earlier – enhances that false perception.

The wording for the link to the ECCC report incorrectly credits Natural Resources Canada.

The June 9 note explaining the first changes to the article falsely and unnecessarily identifies Xuebin Zhang for the “suggestion” concerning changes to the title.

That note lacks transparency about the changes made and it lacks clarity in its formulation.

In addition, that note states that the title was “very slightly modified,” which is superfluous in any explanation for a correction, especially a title.

The September 21 note explaining that a sentence regarding damage claims from extreme weather had been removed also fails to be transparent and frank by attributing it “to another study” rather than dismissing it as did the ECCC report, which is actually cited as a reference at the bottom of the article.

Lastly, various details illustrate the lack of rigour applied to this article even though it was reviewed and corrected multiple times: one sentence ends with a semi-colon and another with a comma, Ontario is misspelled as “Ontarion,” and the legend under the third photo is poorly written (containing an extra and).

Guy Gendron French Services Ombudsman, CBC/Radio-Canada November 19, 2020"

The reference to the title being problematic is fundamental since it says "Climate change: Environment Canada confirms rain becomes more extreme" but the cited material does not support that when it comes to extreme rainfall that drives flood damages.  The Ombudsman rightly acknowledges that the Environment Canada research paper cited confirms that 1 to 5 day "heavy rainfall" has increased (let's call that more "soggy days" that will keep our lawns green, and grow mushrooms), but the study did not confirm that the extreme short duration rainfall that leads to flooding has increases - increases in those rare, severe events have only been projected in models and not confirmed with observations.  The Ombudsman cites the Canada's Changing Climate Report on this fact, noting the cited paper does not confirm extreme events has increased:

"It therefore does not confirm that those extreme events have increased in Canada, as the RCI article would lead us to believe. In fact, according to Canada’s Changing Climate Report, which journalist Marc Montgomery should have read because he references it in his article, current data does not show any increase in those extreme events. Here is what the report specifies on page 155:

For Canada as a whole, observational evidence of changes in extreme precipitation amounts, accumulated over periods of a day or less, is lacking.

Later, a chapter is devoted to “extreme precipitation” and the first section covers “observed changes.” 

The opening sentence of that section on page 168 is:

There do not appear to be detectable trends in short-duration extreme precipitation in Canada for the country as a whole based on available station data."

***

CityFloodMap.Com blog readers will know that we have reported on these extreme rainfall trends across Canada and confirm that rare, extreme rainfall intensities (say with return periods of 20, 50 or 100 years), have decreased at 226 Environment Canada climate stations, according recent Engineering Climate Datasets updates.  This is a blog post with further details on actual overall changes in extreme design rainfall intensities: 

https://www.cityfloodmap.com/2020/07/how-have-rainfall-intensities-changed.html

Here is a summary graph:

The orange to red dots are 20 to 100 year intensity changes from the Version 2.00 rain intensity datasets to the Version 3.10 datasets.  They are on average less than 1.0, meaning decreasing intensities overall in the new data: 5-minute duration 100-year return period rainfall rates are 1.6% lower on average.  Short duration trends are on the left and long durations on the right.  The green dots are small frequent storm trends - those are up a bit for short durations, but not so much for long durations.  The biggest decreases are for short duration extreme rainfall (the orange and red dots on the very left).

And here are the data behind the chart above:

As we can see the 20 to 100 year rainfall intensities have decreased by 0.4% to 0.6% across all durations overall.  Shorter duration intensities for durations of 5 minutes have decreased the most for these rare events: the 20-year to 100-year intensities have decreased 1.2% to 1.6% respectively on average.

As the intensity of small storms has increased (0.6% for the 2 year return period) one can see that the Environment Canada study cited by Radio-Canada can be right about 1-5 day heavy rainfall ("soggy days" from small storms) increasing without the rare, flood-causing 20 to 100-year extreme rainfall increasing.

***

Some history.

Prior to submitting the above complaint that Mr. Gendron reviewed, colleagues and I had provided both Radio-Canada and CBC Ombudsmen with a detailed review of their June 2019 coverage of the cited Environment Canada research.  Our review contained several recommendations to help improve the accuracy of their reporting on the topic of extreme rainfall and key causes of flood damages.  That review was supported by input from Environment Canada as well, specifically related to the June 2019 reporting.  Thank you to those in the academic engineering community and professional engineering practice for contributing to that review.  It appears the Radio-Canada and their readers can benefit from that shared knowledge and insight into a complex topic that has been consistently mis-reported in the past.  See a previous review of Radio-Canada and CBC reporting errors on this topic in this post:

https://www.cityfloodmap.com/2019/06/cbc-correcting-claims-on-extreme.html

***

IMPORTANT FOLLOW-UP

Radio-Canada management just deleted the problematic Marc Montgomery article: https://ici.radio-canada.ca/nouvelle/1752927/climate-change-rci-ombudsman-revision

For those interested in seeing the original article that was removed by Radio-Canada management, here is the text:

<photo>

A sudden intense downpour in Montreal in 2011 overwhelmed the sewers causing some to turn into geysers powerful enough to lift a car (via CBC-YouTube)

Climate change: Environment Canada confirms rain becomes more extreme

By

Marc Montgomery

english@rcinet.ca

Posted:

Wednesday, June 3, 2020 13:27

Last Updated:

Thursday, November 19, 2020 10:04

A new study by Environment and Climate Change Canada (ECCC) confirms what many have been saying, that climate change has made rainfall events more frequent and more severe and the changes are dominated by human activity. This includes burning of fossil fuels, but also development onto natural green spaces for such things as agriculture and expansion of cities.

The report in the scientific journal Proceedings of the National Academy of Sciences (USA) is entitled, ‘Human influence has intensified extreme precipitation in North America’

<photo>

Residents near the Ottawa River in Cumberland, a community in Ottawa, shore up their properties against a flood in 2019. Communities all along the Ottawa River were threatened by record water levels. (Judy Trinh/CBC)

The study indicates that, “Recent years have seen numerous flooding and rainfall-related extreme events in North America, totaling billions of dollars in damages”;

The report begins with a statement that humans have strongly contributed to the changes noting that while past studies have, “identified an anthropogenic influence on extreme precipitation at hemispheric scales, this study finds robust results for a continental scale. We establish that anthropogenic climate change has contributed to the intensification of continental and regional extreme precipitation”.

The report shows that the so-called ‘one-in-20, 50 or 100-year’ events can be expected to occur with far greater frequency with just a 1-degreeCelsius temperature increase over pre-industrial averages, an increase that has already occurred. It notes with that increase a so-called ‘100 year’ event might occur every 20 years. With a 3-C increase, such extreme events would occur with even far greater frequency,

In January last year, Blair Feltmate, head of the Intact Centre for Climate Adaptation at the University of Waterloo in Ontario indicated that Insurance Bureau of Canada payouts for extreme weather claims have doubled every five years since the 1980’s.

Contributing factors to higher claims include higher property values, building onto known flood plains and building over green spaces and wetlands that help absorb rain mitigate flooding. Still experts say the extreme weather and flooding is the main factor says Natalia Moudrak, director of climate resilience at the Intact Centre.

<photo>

A sudden intense storm with a possible tornado swept through southwestern Ontario in September 2019, with record breaking rainfall and leaving broken trees and damage and many without power. (submitted by Steve Biro-via CBC)

Moudrak says the study further underlines the need for changes to city zoning laws, redrawing of flood plain maps, change in stormwater management and designs, and for building codes to change to reflect new extreme weather realities, a process she says that has already begun in many cases but needs to continue.

Several experts have said preservation and restoration of wetlands and green spaces should also be taken into future plans for flood controls.

Additional information – sources

CBC: Chung/Hopton/Reid: Jun 3/20: Yes we’re getting more extreme rainfall and it’s due to climate change. study confirms

Natural Resources Canada: Canada’s Changing Climate Report 2019

NOTE: Jun 9: the title has been very slightly modified to specify ‘rain’ at the suggestion of ECCC scientist Xuebin Zhang who also suggested noting human activity as fossil fuel burning and development onto green spaces.

Sep 21: a sentence regarding damage claims from extreme weather mistakenly referred to another study than the one cited here and as such has been removed.

Categories: Environment & Animal Life

Tags: climate change, environment, extreme weather, study

Do We have Enough Climate Stations in Canada To Track Trends in Extreme Rainfall?

Some have suggested that we have lost so many climate stations due to cut backs in the 1990's that we can't accurately detect trends in extreme rainfall.  But many are confusing manual climate stations with the stations that collect rainfall intensity data, often automatically.  The number of stations measuring extreme rainfall has been increasing since 1990.

Declining number of stations was noted in the ECO's report 2018 GREENHOUSE GAS PROGRESS REPORT CLIMATE ACTION IN ONTARIO: WHAT'S NEXT? - (see Appendix D)
https://docs.assets.eco.on.ca/reports/climate-change/2018/Climate-Action-in-Ontario.pdf

CBC New has also referred to this concept in responding to a complaint to the CBC Ombudsman regarding accuracy in reporting on extreme weather trends.  What has been cited as evidence of that decline is the chart in Appendix D in the ECO report above. CBC's Director of Journalistic Standards Paul Hambleton wrote:

"The report suggests several possible reasons for this inconsistency, including issues with data collection: There simply are not enough rain gauges. Rainfall data is collected using rain gauge buckets that can record both amount and intensity of rainfall. After a series of federal budget cuts in the 1990s, there are fewer rain gauge stations across the country than there were 60 years ago."

Fewer rain gauge stations? Or fewer "manual" rain gauge stations?  Yes there is a difference.

What does that chart show?  It summarizes declining manual stations in Canada and is a excerpt from the paper in Atmosphere-ocean An Overview of Surface-Based Precipitation Observations at Environment and Climate Change Canada (Mekis et al., 2018) - https://www.researchgate.net/publication/324041502_An_Overview_of_Surface-Based_Precipitation_Observations_at_Environment_and_Climate_Change_Canada

The chart of manual station count in Canada is Figure 2a in the paper on the left below.

Number of Manual Climate Stations in Canada

This chart has been referred to in discussions on extreme rainfall trends.  For example, in the ECO report this chart has been related to intensity-duration-frequency of isolated localized storms as in the excerpt at right:

Readers of this blog will have seen extensive analysis of the trends in extreme rainfall across Canada, including annual maximum series and intensity-duration-frequency (IDF) trends.  The data used is that of Environment and Climate Change Canada, distributed in the Engineering Climate Datasets.

What do Engineering Climate Datasets show us in terms of number of stations that collect and analyze extreme rainfall and IDF trends - they have been increasing!  And the number of station-years of data has been increasing - that means more long-term data to support more reliable statistical analysis.  Good news. The following table summarizes the trends:

Number of Climate Stations in Canada With Rainfall Intensity Analysis

The newer datasets include more stations, a 22% increase in station count since 1990. And the number of station-years has increased by 48% since 1990 - that's almost 50% more data to analyze and derive IDF design curves since I graduated and started working in this field.

How have the number of stations with extreme rainfall analysis, increasing since 1990, compared to the number of manual stations decreasing since 1990? See chart below:

Number of Climate Stations in Canada - Manual and Intensity-Duration-Frequency Stations.  Manual stations decreasing while IDF stations and number of station-years of data increasing. (note: v2.00 (557 stations) and v3.00 (596 stations) not shown on chart)

The Mekis et al. figure is shown in blue and the IDF station trends in orange. Obviously the decline in manual stations does not relate at all to the trends in IDF stations.  As noted in other blog posts, municipal IDF stations have also proliferated over past decades, complementing the IDF stations charted above.

So when CBC's Paul Hambleton writes: "After a series of federal budget cuts in the 1990s, there are fewer rain gauge stations across the country than there were 60 years ago" he missed an important detail - yes manual stations that are expensive to operate have declined, as we expect.  It makes sense that we have fewer manual climate stations since 1990. 

Technology changes.  A good summary of the changes in equipment is described by Mekis et al. - image above are from the website https://www.wikiwand.com/en/Rain_gauge that describes the history of rain gauges and their evolution.

But what about automated weather stations? And what about the number of stations used to collect extreme rainfall information and rainfall intensities? Has the number of stations that define extreme rainfall decreased since 1990? No.

IDF stations have increased from 532 to 651 stations since 1990, many with longer periods of record - we have more extreme weather data to rely on today!  The CBC and others should clearly be more careful when interpreting data on climate station and extreme rainfall  monitoring.  

Yes, we're getting more extreme rainfall, and it's due to climate change, study confirms .. well not so fast

CBC News has a new report "Yes, we're getting more extreme rainfall, and it's due to climate change, study confirms" https://www.cbc.ca/news/technology/extreme-rainfall-climate-change-1.5595396

The byline is "Federal scientists predict more frequent and severe rainfall in future", referring to this research paper Human influence has intensified extreme precipitation in North America by Megan C. Kirchmeier-Young and Xuebin Zhang
https://www.pnas.org/content/early/2020/05/26/1921628117

The research paper refers to "heavy rainfall", i.e., Kirchmeier-Young the lead author and research scientist at Environment and Climate Change Canada stated "We're finding that in North America, we have seen an increase in the frequency and severity of heavy rainfall events."

Kirchmeier-Young also refers to "extreme rainfall" and makes a connection to urban flooding in the CBC article:

"And as we continue to see warming, we will continue to see increases in the frequency and severity of extreme rainfall," Kirchmeier-Young said. "And heavy rainfall is one of the major factors in flash flooding, particularly in urban areas."

The CBC relates extreme weather to rising insured flood damage trends in Canada since the early 1980's.

Let's review:

1) What 'heavy rainfall' events were reviewed in Kirchmeier-Young's research paper?

2) Is 'heavy rainfall' for a climate researcher the same as 'extreme rainfall' for an engineer?

3) Do 'heavy rainfall' and precipitation trends follow 'extreme rainfall' trends used in engineering design?

4) Do 'heavy rainfall' events studied in the research paper cause damaging flood events, and flash flooding 'particularly in urban areas?

5) What are the trends in 'extreme rainfall' in Environment and Climate Change Canada's Engineering Climate Datasets, the data used by engineers to analyze and design infrastructure to manage flash flooding risks in urban areas?

6) What does Kirchmeier-Young's research paper reveal about previous extreme rainfall and flooding events in Canada - has climate change increased runoff that could aggravate flood damages?

1) What 'heavy rainfall' events were reviewed in Kirchmeier-Young's research paper?

The research paper abstract indicates "Here, we address the question of whether observed changes in annual maximum 1- and 5-d precipitation can be attributed to human influence on the climate."

What does "1- and 5-d precipitation" mean?  This is the amount of rainfall over one to five days, so 24 to 120 hours. While precipitation can include snowfall too, the focus is on rain.

Note, the research paper actually refers to 'heavy precipitation' and not 'heavy rainfall'.

The authors have confirmed that short-duration rainfall was not reviewed, only annual maximum daily rain.

2) Is 'heavy rainfall' for a climate researcher the same as 'extreme rainfall' for an engineer?

No.

The research paper states:

"We focus on the annual maxima of 1-d (Rx1day) and 5-d (Rx5day) rainfall. Rx1day is important for flash floods as well as infrastructure design. Rx5day is relevant to large-scale river flooding."

A training session on the use of rainfall intensity design curves from a climate scientist (link: http://projects.upei.ca/climate/files/2012/07/IDFtraining-Auld-final.pdf) indicates that shorter times influence flooding (underline and all-caps emphasis are in the original material, not added here):

 "An urban centre could experience flooding from heavy rains falling over a SHORT period of time, such as A 5 TO 30 MINUTE PERIOD."

"• A rural highway with deep ditches on its shoulders would not likely be impacted by an intense rainfall lasting only 5 to 15 minutes, although the paved road itself would see ponding of water.
• A heavy rainfall event lasting 1 to 6 hours might be more significant for filling the ditches and overflowing the roadway."

So short durations are important for flooding.

From the insurance industry perspective, an Institute for Catastrophic Loss Reduction paper in Journal of Flood Risk Management notes the importance of short-duration rainfall (link: https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/jfr3.12168) states

"Subdivisions built before the 1970s are less likely to be serviced by major systems (Watt et al., 2003), and are thus more vulnerable to overland flooding from extreme short-duration rainfall events."

A civil engineer will tell you that rarely that the a 1-day rainfall is not 'important for flash floods'.  Why? Because urban flooding is caused by short-duration rainfall.  Designers of storage facilities such as stormwater manage ponds may consider design rainfall events up to 24 hours.

In the Canadian Water Resources Journal, authors of Flood processes in Canada: Regional and special aspects (link: https://www.usask.ca/hydrology/papers/Buttle_et_al_2016.pdf) representing six universities across Canada, INRS-ete, and Environment Canada review "key processes that generate floods in Canada":

"Similarly, floods can be generated across most of the country by rainstorms with large depths and/
or intensities (Figure 1). Thus, convective and frontal systems can generate large short-duration rainfall intensities (Alila 2000) which can occur in all regions (Table 1). Nevertheless, the significance of such storms to flood generation varies across the country, with the greatest
depths and intensities for short-duration events in southern parts of Canada and the smallest in the Arctic. These short-duration events are often responsible for flood generation in relatively small drainage basins, given the greater chance of high-intensity rainfall occurring over
the entire basin (Watt et al. 1989)."

"Short-duration events are often responsible for flood generation".

"Small drainage basins" is equivalent to urban drainage systems. In the municipality where I was Manager, Stormwater our storm sewer drainage systems averaged just over 50 hectares in size.  Urban drainage systems that are 'flashy', responding quickly to rainfall running off hard surfaces, are characterized in engineering design by a 'time of concentration' that is the response time of the drainage area, and which is used to determine the extreme rainfall durations relevant to infrastructure design.  It is never 24 hours or one day.  Typical times of concentration are measured in minutes and up to hours.

The Ontario Ministry of Transportation describes the design rain storms that may be used to analyze rural and urban areas, including the duration of the storm (link:   http://www.mto.gov.on.ca/english/publications/drainage/stormwater/section10.shtml):

Storms of duration up to 24 hours are applicable to rural land uses.  Storms of up to 4 hours (including flashy Chicago hyetograph temporal distributions) are applicable to urban areas.  The SWMM Knowledge Base, a discussion forum for the standard U.S.EPA Stormwater Management Model and other modelling platforms, provides insight into what storm durations practicing civil engineering / urban system modelling professionals use.  In the discussion thread "Design storm duration" (link: https://www.openswmm.org/Topic/3967/design-storm-duration) a duration of 24 hours is deemed by one practitioner to be 'ultra conservative' ("ultra conservative choice of a 24-hour storm but it hardly can be justified when no detention storage is involved"), another states that in small urban systems the 5-minute rainfall governs peak flows ("a small (25 acre) urban, very impervious, drainage area was that the peaks were almost the same no matter the duration, and that they were driven by the peak 5-minute rainfall"), and Ben Urbonas, Ben Urbonas,
President of Urban Watersheds Research Institute and Owner, Urban Watersheds, LLC (LinkedIn: https://www.linkedin.com/in/ben-urbonas-2a319338/)  notes the use of durations of 2-6 hours ("All of our design storms are front loaded intensity types and range from 2-hour to 6-hour durations depending on watershed area.").

Marsalek and Watt's paper Design storms for urban drainage design in the Canadian Journal of Civil Engineering shows design storm durations of often 1 hour duration, sometimes up to 6 hours (US Soil Conservation Service (SCS) for rural areas, as highlighted in their Figure 1.

Marsalek and Watt tablulate design storms with duration and categorize the use of the storms for different hydrological studies, including urban/sewer design and other applications, such as the study of large rural basins. Table 2 from their urban drainage review shows durations of up to 1- 12 hours for Canada's Atmospheric Environment Service's (AES) storm, and 1, 3 and 4 hour storms for sewer sizing in other jurisdictions (see highlights below).

Practitioners in Ontario, Canada will know that longer duration storms are considered for large regional wastewater systems that have a slow response to long-high volume storm events.  These govern large trunk sewer system performance, but not local sewer system performance that is dominated by short duration rainfall.  Even small wastewater system trunks may be governed by short duration rainfall intensities where there are direct inflows, which is common for many flood prone systems.  Analysis of trunk system response in the Kitchener-Waterloo Region showed wastewater trunk peaks flows for most-highly correlated to the 5-minutes rainfall intensities in on Master Plan study (i.e., more than longer durations).

Rivard's paper in the Journal of Water Management Modelling entitled Design Storm Events for Urban Drainage Based on Historical Rainfall Data: a Conceptual Framework for a Logical Approach (link: https://www.chijournal.org/Journals/PDF/R191-12) summarize early work on characterizing storms in Canada and in the highlighted excerpt notes that 1- 12 hour durations represented convective (thunderstorm) and synoptic scale events. See the highlight to the right.

Rivard also summarized what storm durations are of interest for urban design graphically as follows:

So in small to medium basin, up to a 3 hour duration is critical, and for a very large urban basin, up to 6 hours.  Twenty four hour durations and longer are critical to large rural basins.

The statement "Rx1day is important for flash floods as well as infrastructure design." is therefore inconsistent with professional engineering practice in Canada.

Environment and Climate Change Canada publishes Engineering Climate Datasets including Intensity-Duration-Frequency statistics describing rainfall, both common, moderate and extreme, used from infrastructure design.  The durations analyzed are from 5-minutes to 24-hours.

So again, no, 'heavy rainfall' in a climate research paper is not the same as 'extreme rainfall' an engineer uses for infrastructure analysis and design. Rainfall over 1-5 days periods is not the same as extreme rainfall over minutes to hours used to design conveyance systems in urban areas - those 'flashy' systems with short 'time of concentration' characteristics.

The statement in the research paper "Rx1day is important for flash floods as well as infrastructure design." is questionable.  One-day rainfall is way at the fringe of influence on flash flooding.

3) Do 'heavy rainfall' and precipitation trends follow 'extreme rainfall' trends used in engineering design?

Kirchmeier-Young's research found that 1-day duration simulated precipitation from various models has increased over past decades, and this trend follows observations from HadEX2 (a global gridded dataset).

We can compare the HadEX2 trends across North America, and subregions shown in the research paper, with extreme rainfall trends based on Canadian climate station observations.  Let's start with the 1-day, 24-hour annual maximum rainfall trends across Canada.

The chart below shows how annual maximum rainfall has changed according to Environment and Climate Change Canada's version 3.10 Engineering Climate Datasets for all storm durations from 5-minutes to 24-hours.

For 24-hour durations, 4.9% of all stations have a significant increase, 91.2% have no significant change, 2.3% have significant decreases and 1.5% of stations had no data.

Comparing to earlier datasets:

                                                     Version 2.30           Version 3.00            Version 3.10

No significant 24-hour trend            91.5%                    91.1%                         91.2%

Significant 24-hour increase              5.3%                      5.4%                           4.9%           

So the percentage of data that has no significant trend is relatively steady, and represents over 90% of the data. The percentage of data that has a significant increase in 24-hour rainfall is decreasing relative to the earlier datasets.

Canadian Engineering Climate Dataset trend data does not show increases consistent with the research paper.

4) Do 'heavy rainfall' events studied in the research paper cause damaging flood events, and flash flooding 'particularly in urban areas?

No.  Flash flooding is due to short duration, high-intensity rainfall.

The severe thunderstorms that are responsible for urban flooding and that occur over minutes to hours are different than the storms that occur over hours to days as indicated in the RSI IDF training presentation noted above:

For this reason, those interested in turban flooding drivers should look at short duration rainfall extremes - see below.

5) What are the trends in 'extreme rainfall' in Environment and Climate Change Canada's Engineering Climate Datasets, the data used by engineers to analyze and design infrastructure to manage flash flooding risks in urban areas?

Short duration rainfall is responsible for urban flash flooding.  Environment and Climate Change Canada's Engineering Climate Datasets indicate the following on annual maximum rainfall trends across Canada:

The short durations from minutes to a couple hours have low percentages of significant increase, just like the 24-hour data noted above.  The amount of significant increases expected due to chance is 2.5% increasing and 2.5% decreasing.

In a review of an earlier dataset by Environment Canada's Shephard et. al in 2014 (link: https://www.tandfonline.com/doi/pdf/10.1080/07055900.2014.969677) these amounts of changes were deemed not significant:

"Based on this IDF single station analysis, and the more general single station climate results from the 1965–2005 period presented in Section 4a, we conclude that the annual maximum short duration rainfall values across Canada typically do not show a significant trend."

And more recently in Canada’s Changing Climate Report, such changes in short duration extreme precipitation were explained by chance (link: https://changingclimate.ca/CCCR2019/):

"There do not appear to be detectable trends in short-duration extreme precipitation in Canada for the country as a whole based on available station data. More stations have experienced an increase than a decrease in the highest amount of one-day rainfall each year, but the direction of trends is rather random over space. Some stations show significant trends, but the number of sites that had significant trends is not more than what one would expect from chance (Shephard et al., 2014; Mekis et al., 2015; Vincent et al., 2018)."

The short duration intensities used for infrastructure design, derived based on annual maximum series, have not increased in many regions based on compiled studies (see previous post: https://www.cityfloodmap.com/2018/03/extreme-rainfall-and-climate-change-in.html).  A review of design intensities in southern Ontario shows overall increases in short duration values (see previous post: https://www.cityfloodmap.com/2020/05/southern-ontario-extreme-rainfall.html).

So no change in how infrastructure is designed based on short-duration design intensities (that is, not including checks or 'stress tests' for future changes).

6) What does Kirchmeier-Young's research paper reveal about previous extreme rainfall and flooding events in Canada - has climate change increased runoff that could aggravate flood damages?

Nothing.  The storms that lead to widespread urban flooding are not addressed in the research paper.  The processes driving 1-5 day rainfall are different than those driving short-duration rainfall.  There are no significant increases in the short-duration rainfall that causes flooding based on Engineering Climate Datasets as shown above.

Why then have damages increased over decades? Possible reasons are:

a) growth in net written premiums: more insured properties = more losses

b) urbanization: more pavement means more runoff and impacts

The landmark case Scarborough Golf Country Club Ltd v City of Scarborough et al. (Ontario Court of Appeal, 1988, http://members.storm.ca/~river/letters/Scarboro%20Golf%20Club%20v%20City%20of%20Scarboro%20OCA%201988.pdf) decision indicates that Toronto-area urbanization markedly increased runoff stresses that caused runoff, erosion and flooding:

“Expert evidence confirmed the effect of the city&#39;s rapid urbanization and water control plans on the creek.”

“It is important to note that the case is not presented primarily as a complaint against flooding but
rather that the markedly increased flows and increased velocity of flow have caused and continue to
cause damage to the creek bed and the adjacent tableland.” and

“There can be no doubt that the storm sewer facilities and urbanization of the lands to the north of the Club are the cause of the effects just described and that the difference in flow and velocity of flow is very substantial.”

Cities are growing and there is more runoff as shown here in some regions:



c) inconsistent data: the data source for losses cited by CBC changed from 2008 onward

Changing data methods can lead to different results (see previous post on this: https://www.cityfloodmap.com/2018/06/catastrophic-losses-in-canada-have.html)



***

The research paper makes a reference to an attribution study for the 2013 Alberta flood.  It states:

"Additionally, event attribution studies have identified an increased probability of some individual extreme precipitation events in this region due to anthropogenic influence (4, 5)"

Reference 4 is:

B. Teufel et al., Investigation of the 2013 Alberta flood from weather and climate
perspectives. Clim. Dynam. 48, 2881–2899 (2017). (link: https://link.springer.com/article/10.1007/s00382-016-3239-8)

So we have one Canadian storm assessed. Findings are:

"Event attribution analysis suggests that greenhouse gas increases may have increased 1-day and 3-day return levels of May–June precipitation with respect to pre-industrial climate conditions. However, no anthropogenic influence can be detected for 1-day and 3-day surface runoff, as increases in extreme precipitation in the present-day climate are offset by decreased snow cover and lower frozen water content in soils during the May–June transition months, compared to pre-industrial climate."

So greenhouse gases may have increased precipitation, but that is offset by less snow, resulting in no change in runoff, compared to pre-industrial climate.

So with no change in runoff, can there be a change in flood damages attributed to the precipitation change?  The net effect is no increase in risk.

***

To wrap it up, CBC has relied on a research paper that looks at rainfall events (1-5 day precipitation) that are not related to urban flash flooding and are not related to the events that lead to significant damages (convective thunderstorms with peak intensities over minutes to hours).  The research does not review short-duration rainfall that is relevant to infrastructure design governed by short 'times of concentration' - i.e., they are 'flashy'.  The research does not appear to be consistent with trends in 24-hour annual maximum rainfall observed at Canadian climate stations and as published in Environment and Climate Change Canada's Engineering Climate Datasets - data show few statistically significant increases and the percentage of significant increases is decreasing slightly for 24-hour rainfall across Canada.  The short-duration rainfall intensities responsible for urban flooding show no consistent changes, and any significant changes are explained by chance, according to Environment Canada.

Many factors go into increasing flood damages.  Changes in rainfall does not appear to be one of those factors.  Media should take the time to dive deeper into the technical details they reference to improve the accuracy of reporting, so that the public is better informed about complex issues.
Urban flooding is a complex issue, and an important challenge to address that requires significant funding and attention.  A better understanding of the causes of flooding, and any changes in design rainfall, is required to mitigate flooding in the most objective, cost-effective manner.  CBC has relied more on model predictions than on actual data in the past, even confusing the two (see previous post: https://www.cityfloodmap.com/2020/05/what-covid-19-taught-us-about-observed.html).  In this recent report it has not met its JSP principle for accuracy by confusing longer-term precipitation and short-duration extreme rainfall.

***

BONUS - Trends in short-duration rainfall, based on annual maximum observations, from Environment Canada's version 3.10 Engineering Climate Datasets are summarized below (link: https://climate.weather.gc.ca/prods_servs/engineering_e.html).  These tables consider stations with a long period of record and recently updated data for regions across Canada.

What COVID-19 Taught Us About Observed Data vs. Model Projections: They Are Different - Let's Remember That When Interpreting Climate Models

COVID-19 - observed data on ICU cases and projected capacity

"All models are wrong, some are useful".  Predicting COVID-19 conditions has taught us that models come with a great deal of uncertainty, and are based on a lot of assumptions.  Furthermore, models have to be constantly updated over time with real observed baseline data to represent the starting point for future predictions. At least we recognize the difference between theoretical model projections and the past observations on COVID-19 conditions.  More attention should be given to the difference between theoretical models of climate effects and observed changes in extreme weather.

In early April, COVID-19 ICU cases were projected to increase to 1200 in a best case to about 1500 in a worst case in Ontario, increasing considerably from actual data counts in late March.  The chart at right shows that ICU beds peaked at under 300 cases by mid April, a fraction of the best case model prediction, and has declined since.  So model projections should be viewed with some caution, and the reliability of the projections should be questioned and validated where possible with real data.

Predicting future weather extremes due to climate change effects has a great deal of uncertainty as well.  The recurrence time of extreme rainfall is predicted to decrease due to climate change effects, meaning that the "return period" of storms would become smaller.  For example, a rainfall event that had a return period of 35 years today (meaning a probability of occurring in any year of 1/35, or 1 in 35) has been predicted to occur every 12 years in the future (i.e., a higher probability of happening each year of 1/12 or 1 in 12 ... that a greater chance than today's 1/35).  That is what is projected to occur in Canada from now to 2100.

The above example on decreasing recurrence times is from a simulation presented in Canada's Changing Climate Report by Environment Canada (link: https://changingclimate.ca/CCCR2019/).  It is for a future scenario with several assumptions about growth and emissions called the RCP8.5 scenario, representing a Representative Concentration Pathway of just one of several future scenarios.  The shift in 24-hour precipitation recurrence times are presented on Figure 4.20 b shown below:

Canada's Changing Climate Report Figures 4.20 b), Projected Extreme Precipitation Recurrence Time / Return Periods for Past, Present and Future Time Periods, RCP8.5 Model Simulation Scenario

As annotated above, today's recurrence time is noted as 35 years, the future recurrence time is 12 years and the past time was 50 years. So the model predicts these shifts in recurrence time (return period) and annual probability:

   Period         Recurrence Time       Probability Each Year
1986-2005             50 years                       2.0 %   (1/50)
2016-2035             35 years                       2.9 %   (1/35)
2081-2100             12 years                       8.3 %   (1/12)

Some have misinterpreted the theoretical, simulation model changes from past to present as 'actual' observed changes in extreme precipitation when in fact the Environment Canada report clearly notes these are 'projected changes' and are 'simulated by Earth system models' for the scenario RCP8.5.  A different scenario's simulated results, with different assumed emissions and growth, and different recurrence time shifts are presented in Figure 4.20 a) as well.

CBC News In Our Backyard - Flooding

CBC's In Our Backyard interactive notes "Climate change is no longer theoretical. It’s in our backyard" - unfortunately it presents theoretical past model trends as real changes that are "In Our Backyard" now.  Here is the online report link: https://www.cbc.ca/news2/interactives/inourbackyard/

CBC News report: "Climate change is making extreme rainfall a more frequent occurrence. Storms that historically happened only once every 50 years are now coming every 35 years or less. By the end of the century, they could happen once every 12 years on average, according to a recent climate report from Environment Canada. All this increases the potential for urban flooding."

CBC News In Out Backyard Extreme Rainfall Frequency - Past, Present, and Future Recurrence Times Confuses Simulation Model Projections With Observed, Historical Trends

So while predicted changes are only theoretical, CBC News mistakenly reports that changes have already occurred and are 'now coming' at smaller recurrence intervals (i.e., higher frequency and higher probability each year).

The CBC Ombudsman has indicated that the CBC should be careful to distinguish between past, present and future extreme rainfall trends, as noted in a recent post: https://www.cityfloodmap.com/2020/05/past-present-or-future-cbc-ombudsman.html

We agree.

A review of historical extreme rainfall trends in one region of Canada affected by may flooding events has shown no decrease in the recurrence time, or return period, of extreme precipitation.  A previous post showed that today's 35 year storms are actually occurring less frequently than in the past. In southern Ontario, long term climate station observations show that the average 25 to 50 year rainfall intensities today are actually slightly smaller than they were considering observations up to 1990. See previous post: https://www.cityfloodmap.com/2020/05/southern-ontario-extreme-rainfall.html

Analysis of the Version 3.10 Engineering Climate Datasets IDF Files updated in March 2020 show that southern Ontario long term rainfall intensities have decreased slightly since 1990, on average by 0.1%.  The 50 year return period rainfall intensities are on average unchanged.

If 50 year rainfall intensities actually occurred more frequently and now occur at a 35 year return period, as CBC mistakenly reported, then the magnitude of the 50 year intensities would have had to increase by about 6%.  This considers the example long term climate station at Toronto's Pearson International Airport - the 35 year 24-hour rainfall intensity of 99.7 mm at the airport would have to increase to the 50 year intensity of 105.7 mm.  Back in 1990, the 50 year 24-hour rainfall intensity at the airport was 109.3 mm, meaning the 50 year rainfall has decreased by several percentage points.  Here are the 1990 data (copied from my top desk drawer):

Toronto Pearson International Airport IDF Table With Data Up to 1990 - 50 year design rainfall intensity of 109.3 mm  (shown here) was higher than today's version 3.10 Engineering Climate Datasets intensity of 105.7 mm (see table below to 2017).  

Here are the recently updated IDF values from Environment Canada considering data up to 2017:

Toronto Pearson International Airport IDF Table With Data Up to 2017 - 50 year design rainfall intensity of 109.3 mm (see previous table to 1990) shown is lower than today's version 3.10 Engineering Climate Datasets intensity of 105.7 mm (shown here).

Climate models that predict more frequent future rainfall intensities, characterized by shorter recurrence times (i.e., lower return periods = higher probabilities of occurrence) are not necessarily in step with observations (see Toronto airport example above and previous post on southern Ontario long term stations).  Here is a comparison of past trends in 100-year rainfall intensity based on observed data and projections from various studies - the actual data curve is already 'flat', so the need to flatten the curve can only be made based on projections and not past data.

Extreme Rainfall IDF Trends - Toronto 24-Hour 100-Year Rainfall Volumes per Environment Canada Engineering Climate Datasets - Past Data and Linearly Projected Trends Shown in Black.  Various Studies and Models Project Significant Increases That Have Not Shown Up In The Data Observed Data Statistics

Just like COVID-19 models have considerable uncertainty and must rely on observational data to calibrate and validate them - so they they are more reliable and useful in making projections of the future - climate models require checks on accuracy and usefulness.  Media like CBC News may not discern between model predictions and actual trend data which can mischaracterize trends in extreme weather.  Since models predicting extreme rainfall do not appear to match past observations over the recent past few decades, the accuracy and reliability to project conditions over the next 80 years should be closely scutinized.

While in the case of COVID-19, the need for "flattening the curve" is clear given the close scrutiny of observed data that has shown rising counts of infections, hospitalizations or deaths - that gives clear direction on actions to be taken to mitigate observed phenomena.  In the case of COVID-19, these values may even increase at an exponential rate.  In contrast, the IDF curve trends are largely flat if not already declining based on observed data in some regions.  Any change in extreme rainfall trends has been explained by natural variations (i.e., trends can go up).

***

There is a long-standing gap in the media mixing up predictions of extreme weather and actual Environment Canada observed data trends - sometimes a single report can start a narrative that can go unchecked for some time.  The "Telling the Weather Story" report is one such example where a theoretical shift in extreme weather has been reported, and repeated endlessly in the media as actual data when it is clearly not:

Storm intensity not increasing - factual review of engineering data - Canada and Ontario from Robert Muir

Assessing the Damage. CBC Ombudsman Finds Wrong Flood Damage Values Reported, Notes "broader concern that there is a pattern of imprecision in CBC’s coverage relating to flood events"

The CBC Ombudsman has found violations in the CBC’s Journalistic Standards and Practices related to an April 11, 2019 article entitled "Canada's building code is getting a climate change rewrite. Is your home ready?" (link).

The violations relate to publishing the wrong value for flood damages resulting from a Toronto August 2018 storm, and failing to note corrections to an article.

The CBC has always been very responsive to feedback on extreme weather reporting, including on the frequency of extreme events.  In January 2019, the Ombudsman also found violations related to reporting of more frequent extreme rainfall events (i.e., 100-year storms) - corrections to a couple stories were required.  Those Ombudsman's findings are noted in a previous post.  Other CBC story corrections have been made since 2015, again relating to storm frequency and the causes of flooding, and are noted in this previous post.

The new Ombudsman findings are described here.

While the complaint surrounding the April 11, 2019 article is related to a single storm, the Ombudsman noted that there is a broader issue stating:

"I have a broader concern that there is a pattern of imprecision in CBC’s coverage relating to flood events."

This comment is based on the fact that the cited average flooded basement claim or payout was $43,000 was really based on an extreme 2013 flood event in Toronto - not an average at all - yet it has been repeated over and over by the media including CBC.

A previous post shows how this value started (as $40,000 back in 2017) and how it has been expanded to cover the whole country.  It has been used in Intact Centre on Climate Adaptation's infographics as well:

Intact Financial Corporation's website refers to the $43,000 value too:

Global News. The Globe and Mail. Canadian Underwriter. TVO's The Agenda. All repeat the incorrect $43,000 value. Only CBC has been keen enough to entertain a review and make corrections to the record.

The full review is noted below for reference

***

Assessing the Damage

• Sep 20, 2019

CBC reported that concerns about climate change are causing government to re-think the rules for construction of buildings and infrastructure. Complainant Robert Muir took exception to several details in the online article. Among them was an estimate of damage caused by one particular storm, which led to this review about expert sources, and the importance of precision in journalism.

COMPLAINT

You listed four deficiencies in the original version of a story headlined Canada's building code is getting a climate change rewrite. Is your home ready? which was published on April 11, 2019.

The article concerned various proposals to create tougher standards for the construction of buildings and infrastructure projects in Canada. It explained to readers that governments are considering these changes in order to mitigate the expected impact of a changing climate.

Two of your points prompted CBC News to make amendments to the article. One concerned wording that implied that predicted changes in extreme rainfall events had already been demonstrated. The other concerned the use of incorrect terminology to describe a backwater valve. Many homeowners will recognize this device which can decrease the risk of a sewage backup in their home.

Your third point suggested the article should have more fully addressed the cost effectiveness of the various proposals.  In response, CBC News explained that this was outside of the scope of this particular article. 

You were satisfied that those three points were properly addressed. However, on your fourth point, you requested a review. The remaining dispute relates to a section of the article which included an interview with Natalia Moudrak, Director of Climate Resilience at the University of Waterloo's Intact Centre. At one point she discussed the amount of damage caused to homes by flooding in Toronto.

Here is the relevant excerpt of the article:

While architects and construction workers grapple with reducing emissions from large buildings, average Canadians will face other problems. 

"Flooding is the biggest challenge" linked to climate change for most homeowners, said Natalia Moudrak, director of climate resilience at the University of Waterloo's Intact Centre. 

And there are measures homeowners can take now to safe address flooding.

If a homeowner has a pump to get water out of a basement, "it's important to install a backup generator," she said. Widespread flooding often leads to power outages, leaving regular pumps useless when they're most needed.

Homeowners can also take simple steps to elevate valuables, like expensive electronics, off their basement floor or put items in plastic or steel containers in case water does creep in, Moudrak said. 

To prevent sewage from flowing into your home during a flood, David Foster, a spokesperson for the Canadian Home Builders' Association, recommends installing a backwater valve, a mechanical backflow prevention device linked to the plumbing and designed to allow water from sewer drains to only flow away from the home.

"There is not a lot of cost involved in that, it just involves changing the way things are done," said Foster, who has consulted with the government on the new code. 

When constructing a new home, installing a backwater valve costs roughly $400, Moudrak said. When retrofitting an existing home, it usually costs about $3,000. But municipalities often offer subsidies to help offset that expense.

The problem, she said, is most people don't know about them.

Only six per cent of Toronto homeowners took advantage of the city's flood resilience subsidy program, she said. When floods hit the city last year, she said the average cost to affected homeowners was $43,000.

The sentence at the heart of your complaint is the very final one. You wrote that the $43,000 figure was “misstated”. It reflected the Intact Centre’s Toronto 2013 Flood Report, not the 2018 one (i.e. - the article states “last year”). You also suspected that the calculations of the estimate are based on studies done in the United States by the National Flood Insurance Program.

You said more accurate numbers could be obtained from the CatIQ database, which you describe as “the definitive source for compiled flood damages from Canada’s insurance companies.” Based on the number of claims and total value of payouts from the 2018 storm, you suggested that a more accurate number was $18,509 rather than $43,000. You wrote:

I believe that it is important to clarify given the fact that urban flooding is a significant issue, the costs of risk reduction are immense, and sound economic data and analysis is required to make evidence-based decisions on damage reduction management strategies. Flood damage data is a key piece of this economic data and many municipalities have cited the $43,000 value in federal infrastructure grant applications, which may not reflect actual damages, and could therefore adversely affect how scarce resources are allocated to address an important infrastructure challenge. 

MANAGEMENT RESPONSE

Paul Hambleton, the Director of Journalistic Standards and Practices, responded on behalf of CBC News:

To be clear, the story quoted Natalia Moudrak, director of climate resilience at the University of Waterloo’s Intact Centre on Climate Adaptation: “When floods hit [Toronto] last year, she said the average cost to affected home owners was $43,000”. That information is also included in “Weathering the Storm: Developing a Canadian Standard for Flood-Resilience in Existing Communities”, a report published in January and co-authored by Ms. Moudrak.

In a footnote, the report attributes that estimate to the Insurance Bureau of Canada (IBC) “based on Toronto flooding in 2013”. However, you wrote, the actual source is FEMA’s National Flood Insurance Program (NFIP) cited in a July, 2012 story in Forbes. The story cites the interactive “Cost of Flooding” found on the NFIP page as estimating nearly $40,000 damage to a 2,000 sq. ft. home after a 6-inch flood.   

It’s interesting to note that in looking at it now, almost seven years later, “Cost of Flooding” estimates damage of a little over $20,000 for a 1,000 sq. ft. home and about $52,000 to a 2,500 sq. ft. one-storey home. (There was no estimate for 2,000 sq. ft. home).

It’s pretty clear that there is a range of estimates and, it seems, little public information about how those numbers were reached. But you have touched on an interesting issue here.

On one level, while reporters can tell us what they see and hear, there are many things that they don’t witness or can’t know. In those instances they attribute the information. That way, readers know the source and can make their own judgment about its reliability. In this instance, we attributed the information to Ms. Moudrak, identifying her position and the organization she works for.

REVIEW

In a perfect world journalists would have expertise in every subject they cover. In the real world, many reporters, along with their editors, are generalists who strive to learn as much as they can in a short time so they can report faithfully and accurately on the subject at hand. 

This means that there are times where they reasonably rely on subject experts to explain how something works, why something happens, or what might happen next. It might be a doctor, a realtor, or a marketing executive. In each case, the reporter looks to use their expertise as a way to improve the story with informed insights. 

In such situations reporters willingly put themselves at the mercy of the expert’s knowledge. If an expert were to give bad information, CBC’s Journalistic Standards and Practices doesn’t let either of them off the hook. There is a section called “Responsibility and Accountability Related to Interviews” which reads as follows:

CBC takes responsibility for the consequences of its decision to publish a person’s statements in the context it chooses. When we present a person’s statements in support of our reporting of facts, we ensure that the statements have been diligently checked. In the case of comments made by a person expressing an honest opinion, we ensure that the opinion is grounded in facts bearing on a matter of public interest.

The interviewee also takes responsibility for his or her statement. As a general rule, we offer the interviewee no immunity or protection from the consequences of publication of the statements we gather.

Sometimes the experts provide a recitation of facts, but not always. Often they are called on to analyze a situation or express an opinion related to their field. It is sensible that there is wide latitude in these cases for what constitutes reasonable comment. Realtors may disagree on which way the housing market is going. Marketers may clash over whether that new trend will fizzle. Doctors may have varying levels of enthusiasm for a prospective new drug.  

The estimate of how much damage the average affected homeowner experienced during Toronto’s big summer storm of 2018 falls into this category of commentary and professional judgment. There is no single demonstrable number that has universal support, so the reporter went looking for someone to estimate the total.

You disagreed with the Intact Centre’s methodology. Instead, you pointed to the CatIQ database, which is an excellent starting point. However, as you know, that database represents only the payouts insurance companies made to people who put in a claim. Others might think you should add in property damage not covered by the insurance policy, or people who opted not to file a claim. There are other expenses that could be considered as well. Should you include the value of time homeowners missed from work as a result? What about the cost of infrastructure repairs absorbed by government, or the cost of policing, firefighters and ambulance drivers? Should they be included or costed separately?

Looked at through a different kind of prism, how much of the damage was caused by flooding, and how much was caused by wind, or by lightning? 

Now, I recognize that you know a great deal about all these subjects. You have your own expertise, and you have told me about work you are doing that seeks to consider both direct and indirect costs to come up with a ratio of overall losses to insured losses. However, it is apparent that determining an estimate has at least some degree of subjectivity. 

With all that in mind, it was acceptable journalistic practice for the CBC reporter to use the Intact Centre as its expert source and ask them to estimate the damage from a big storm. The Intact Centre is an applied research centre affiliated with the University of Waterloo. That may not bring it reputational immunity, but it does come with an inherent base level of credibility. The reporter was entitled to use Ms. Moudrak as an expert, so long as he attributed the estimate to her. I disagree with you that the JSP standard of “diligent checking” of her statement meant the reporter should have done extensive research to test that estimate. It is more reasonable to believe that diligent checking refers to facts that can be categorically confirmed or refuted, not to a matter of professional judgment such as this. 

Nonetheless, you are correct that the number in the story WAS the wrong number, regardless of the quality of the estimate. The $43,000 figure did not represent the Intact Centre’s estimate for the 2018 Toronto storm, but instead was their estimate for the 2013 Toronto storm - something raised by you in your complaint, acknowledged by Mr. Hambleton in his response, and confirmed in my own communication with Ms. Moudrak.

That this was wrong is, naturally, a violation of policy. That it has not been corrected means it continues to be so. It does not matter whether the original misunderstanding was caused by the source or by the journalist. It ought to be clarified for the record, and for the readers. 

Further, I noted while reviewing the story that there is no note on the web page acknowledging the two other corrections prompted by your initial complaint. This is a second violation of policy.   

I have a broader concern that there is a pattern of imprecision in CBC’s coverage relating to flood events. You provided me with a list of other recent CBC stories which make reference to the $43,000 damage estimate. Several confuse the matter by not indicating this is a specific estimate for the 2013 Toronto floods. One said, “The average basement flood in Ontario costs the homeowner $43,000.” Another said, “The average payout for a flooded basement is $43,000 and rising.”  These types of references take a single (and unusual) event in 2013 and treat it as if it is now a generic standard.

Reporters and editors need to ensure they understand what's included (and what's not) in any estimates provided, and they need to ensure that they associate that estimate with the correct event - or events, as the case may be. Based on my review, that is not happening consistently enough. 

All of this needs to be distinguished from your belief that the Intact Centre’s $43,000 estimate to be incorrect, even when attributed to the 2013 storm. I would encourage CBC News to take your perspective into account, but that is as far as I will go. It is not my intention to take sides on the quality of the Intact Centre’s estimate. If journalists continue to find the Intact Centre credible, they continue to be free to consult them for stories.

Sincerely,

Jack Nagler
CBC Ombudsman