Does Higher Temperature Increase Rain Intensity? Not Always, Observations Show Decreasing Rain Intensity. Southern Ontario Twice As Many Statistically Significant Decreases In Annual Maximum Rainfall.

One degree temperature rise increases water vapour holding capacity
by 7%, but does it increase rainfall intensity?
High school science teachers and media have been saying that temperature increases associated with climate change cause a direct increase in water vapour and therefore, by association, more extreme rainfall.  This has been reported for years, like here in the Guardian where they say "A warmer atmosphere can hold more moisture, and globally water vapour increases by 7% for every degree centigrade of warming."

The Clausius-Clapeyron (C-C)
equation describes the water-holding capacity of the atmosphere as a function of temperature.

Geophysical Research Letters research looks at historical data to see if this theory linking temperature and rain intensity can be verified and what other explanatory variables are available. Researches from Lamont-Doherty Earth Observatory, Columbia University, MIT, and Institute Centre for Water Advanced Technology and Environmental Research (iWater), Masdar Institute of Science and Technology, and Department of Chemical and Environmental Engineering, Masdar Institute of Science and Technology analyzed how extreme rainfall intensities in the USA depend on temperature (T), dew point temperature (Td), and convective available potential energy (CAPE). The analysis considers geographic sub-region, season, and averaging duration.

What did researchers find in the data?:

"When using data for the entire year, rainfall intensity has a quasi Clausius-Clapeyron (CC) dependence on T, with super-CC slope in a limited temperature range and a maximum around 25°C

So Clausius-Clapeyron is only quasi-valid, meaning there is not a strong relationship between rain intensity and temperature. And rain intensities peak at 25 degrees Celcius ... they do not keep going up with temperature increases. The Guardian missed these details. Who else made the temperature-water vapour-rainfall relationship claim:

The magazine Science article How Much More Rain Will Global Warming Bring? touches on the 1 degree - 7 % atmospheric vapour relationship back in 2007. Bloggers around the world repeat this. But lets look at more the the research findings based on actual data in Geophysical Research Letters. These charts show how rain intensities do not increase at the CC rate above 22 degrees:


The fourth column of charts shows temperature T on the x-axis. On the y-axis is slope of the relationship between rain intensity and temperature. The dashed red line is the predicted CC rate, meaning above 22 degrees rain increases less that predicted by CC. So no, this theory does not hold water (pun intended). In fact for some of the highest temperatures for some quantiles in the North Central and South, slope is negative, meaning that increased temperature DECREASES rainfall intensity (black lines go below zero).

Looking at the third column of charts with LnP on the y-axis, we see that for several quantiles of precipitation in both winter and summer, LnP does not reach the predicted rate at all (coloured lines below the predicted rates shown in the black dashed lines). In plain english this means the predicted increase in rain intensity with temperature is never met for small storms, e.g., the ones responsible for erosion, etc. So the theory is flawed for small storms.

In the summer, i.e., black lines in third column, precipitation as LnP flattens out or sometimes decreases at the highest temperatures, mostly in the South and Central of the US - for the lower 2 to 3 quantiles the CC rate is not met or just met. In the North, rain intensity for the lower quantiles of precipitation flattens out and decreases above 25 degree Celcius.

The take-away is that simple relationships make great theories. Real systems are more complicated than the Clausius-Clapeyron (CC) would suggest.

Lets look at something simpler in Ontario, Canada. Temperatures have increased. At right are temperature trends plotted by Statistics Canada. There is an increase from the late 1940's to 2008. Pretty clear.

Below are maximum annual observed rainfall trends for Toronto's long term climate station from Environment and Climate Change Canada's Engineering Climate Dataset Version 2.3, from the 1940's to 2007. It shows decreasing annual maximum rainfall for all rainfall durations from 5 minutes to 24 hours. Obviously the real world data shows us that despite increasing temperature, there is no corresponding increase in maximum observed rainfall.

The hypothesis that rising temperatures result in higher water vapour and then also more extreme rainfall is rejected based on the observations in southern Ontario. While temperatures are up in Ontario, there are twice as many statistically significant decreasing annual maximum rainfall trends as increasing ones as summarized from the Engineering Climate Dataset (version 2.3):

Ontario climate change myth cap and trade policy climate adaptation ROI
More statistically significant DECREASES in rainfall intensity are observed than increases.
For short duration rainfall, the convective storms that cause flash flooding in urban areas, we can look at the duration of 2 hours or less - there is just one statistically significant increase in annual maximum rainfall, and 6 examples of statistically significant decreasing rainfall maximum.

Evidence-based policies for flood mitigation and other stormwater or water resources management activities first require accurate characterization of factors affecting runoff and flow conveyance in municipal and natural drainage systems. By hypothesizing that rainfall intensities are increasing as a result of higher temperatures, flood damage mitigation could be achieved by combating green-house gas emissions to stall temperature increases. Data shows that extreme rainfall is not increasing with temperatures, and therefore an increase in flood damages is due to other factors (e.g., hydrology, hydraulics) - as a result effective flood damage mitigation must focus on key drivers and not temperature or rainfall trends.

We cannot explain severe weather, extreme rainfall, tornados and hail in Ontario with simple relationships that have been shown to contradict observation data.

Environmental Impacts of Green Infrastructure Construction - CO2 Emissions for Soil Removal and Aggregate Extraction & Transportation, Ontario Impacts

Etobicoke Infiltration System - Green Infrastructure for
Stormwater Infiltration and Low Impact Development
Like any infrastructure that requires material resources and energy to construct, green infrastructure is no different than grey infrastructure. This post looks at a typical low-impact-development (LID) feature for stormwater runoff control and estimates the CO2 impacts of its initial construction, excluding traffic impacts during construction, and excluding impacts for ongoing operation and maintenance, or rebuilding at end of lifecycle. Emissions are then scaled up across Ontario in light of green infrastructure policies being considered province-wide. The GHG emissions are huge for building green infrastructure !

For this example, consider a perforated pipe and gravel trenches for infiltration of stormwater runoff, like the Etobicoke Infiltration system pioneered in pre-amalgamation City of Toronto. This is a typical green infrastructure configuration - see Ryerson University's Planning and Design Manual at this link. We can assume a simple arrangement with the perforated pipe and gravel trench beyond the roadway, say in the boulevard.

Napkin - engineer's friend ... especially when
they run out of envelopes to scribble on the back of.
The construction of the perforated pipe infiltration system requires transport of various materials to and from the construction for initial construction. Lets assume we are considering 1 cubic metre of infiltration storage volume in the system. Some activities and their resulting kilometre-tonnes of transportation are estimated on this blog-napkin, if you will, aka an educated Fermi Estimate:

1) excavation, transport and disposal of native soil material - if the facility is in a retrofit setting the sodium adsorption ratio of the soil (due to road salt chloride accumulation over time) means reuse could be limited. Assume the disposal site may be a distance of 40 km from the construction site. For each cubic metre of infiltration storage, lets assume a 40% voids ratio in the gravel infiltration trench, meaning each cubic metre needs 1/0.4 - 1.2 cubic metres of soil disposed, and at a density of about 2 tonnes per cubic metre. So 40 x 1.2 x 2 = 96 km-tonnes of native soil haulage.


2) transport and placement of clear stone - assume aggregate comes from a quarry 40 km away from the site. For each cubic metre of infiltration storage, and our 40% voids ratio in the gravel, each cubic metre of storage needs 1/0.4 - 1.2 cubic metres of clear stone. At a density of 1.6 tonnes per cubic metre (3/4 inch clear stone), there is 40 x 1.2 x 1.6 = 76.8 km-tonnes of gravel haulage.

The OECD indicates pollution for truck transport in a report that indicates 140 grams of CO2 emitted per tonne-km. So adding 1 +2 above, a total of about 173.8 km-tonnes of green infrastructure construction to achieve 1 cubic metre of runoff storage results in 173.8 x 0.14 = 24.3 kg of CO2 emissions.

3) quarrying gravel - based on 4.32 kg COemitted per tonne from this source, each cubic metre of infiltration storage with 40% voids requires 1/0.4 - 1.2 cubic metres of clear stone. At a density of 1.6 tonnes per cubic metre again, there is 4.32 x 1.2 x 1.6 = 8.29 kg CO2 per cubic metre of storage.

The MOECC is targeting 25 mm or more of green infrastructure storage and/or treatment which means per hectare of urban development with 50% rain/runoff there is 10,000 x 0.025 x 0.5 = 125 cubic metres of runoff and green infrastructure storage needed. So 125 x 24.3 = 3037.5 kg of COemitted per hectare of urban area retrofitted with this low impact development feature. That is just haulage. To quarry the gravel adds 8.29 x 125 = 1036.8 kg per hectare. Total is 4074.3 kg per hectare of green infrastructure runoff treatment. Is that big?

Ontario has 825,000 hectares of untreated urban area.
Given the Ontario-wide 852,000 hectares of urban area that would need green infrastructure retrofits under the draft MOECC policy, the Ontario-wide COemitted to initially build green infrastructure would be 852,000 x 4074.3 = 3,471,303,600 kilograms of COemitted. Say 3.5 million tonnes of CO2 added.

So over 3 billion kilograms to build green infrastructure to manage runoff - you could argue there is some nominal climate mitigation offset-benefit if there is some type of vegetated pre-treatment filter before the perforated pipe / gravel infiltration. If so, that would be offset by the frequent inspection and minor maintenance visits by municipal crews, year after year.

Note in Canada the per capital emission was 20.1 tonnes CO2 equivalent in 2015 according to Environment and Climate Change Canada. So retrofitting green stormwater infrastructure in Ontario will emit CO2 equivalent to all the CO2 emitted by 172,000 Canadians over an entire year. That is just initial construction.

So that is just a neat Fermi Problem on green infrastructure to consider along the the other considerations on cost, cost-effectiveness, impacts to existing infrastructure, and need for scientifically-based local targets for green infrastructure. Currently, MOECC is considering blanket green infrastructure retrofit targets that do not consider any cost constraints or any no environmental impacts of construction like CO2 emissions. Earlier posts note that impacts to iron watermains and flood prone sanitary sewer systems was ignored. Let's hope a more holistic approach emerges that recognizes that we can't build millions of tonnes of infrastructure, green, grey or purple, and not have big impacts to emissions etc.

Green infrastructure for stormwater management, just like green energy for power supply has significant negative impacts. It should not be viewed as a panacea for urban stormwater and water resources management issues in Ontario. Check out this post on costs and other impacts.

Lake Ontario 2017 Water Levels Only 4 centimetres Above 1973 Monthly Maximum. But well above average. Lake Deluge Exceeds Leaf Drought !

See May/June updates at end of original post.
***
Some records are made to be broken, whether its the Leaf's Stanley Cup drought or Lake Ontario flooding. At right are the Leaf logos over the years. See the top right logo they had in 1952? And see the current bottom right logo? Old is new again with the logo, right? Same thing with maximum water levels in Lake Ontario.

Back in 1952, from March to June monthly Lake Ontario levels hit records. In 1973 those April and May records were broken .. April 1973 was just 3 cm above May 1952 average, and May 1973 was a measley 1 cm above May 1952. It has taken 44 years to break the spring records again in 2017.

Below are historical average and maximum Lake Ontario water levels from the Departments of Fisheries and Oceans and Environment and Climate Change:

Lake Ontario Water Level flooding erosion maximum
Lake Ontario Historical Water Levels - Average, Maximum and Minimum Monthly Elevations (right y-xis is elevation
above sea level, left y-axis is depth in metres above reference datum of  74.2 metres).

This is from the April 2017 bulletin available here at this link. The historical average, maximum, and minimum monthly values are shown in the table below (see full table here).



On May 28, 2017 the Lake Ontario Level is 1.69 metres above the reference datum elevation of 74.2 metres, meaning an actual water elevation of 74.2 + 1.69 = 75.79 metres above sea level. Hourly levels can be graphed or tabluated from this site. The graph below shows lake levels generally leveling off and rising slightly in the last weeks of May 2017 (y-axis is the depth above the datum):

Lake Ontario water levels flood shoreline erosion
Real time Lake Ontario water depth above reference datum of 74.2 metres up to May 28, 2017.

Relative to maximum historical values, the May 28, 2017 depth of 75.69 is 4 centimetres above the previous 1973 May monthly maximum of 75.65, and 4 cm below the previous June monthly maximum of 75.73 m. And 75.69 is just 7 centimetres above the 1952 May average. We visited the Outer Harbour Marina yesterday and levels have flooded the fixed perimeter dock / walkway so that temporary paths to the boat slips have been made - so yes, levels are above average and many fixed shore features have been built for the averages and not the maximum levels.

The current Lake Ontario levels are causing a higher erosion potential further inland with waves nearly undermining the boardwalk near Woodbine Beach as shown in this picture:

Lake Ontario water levels
Beaches boardwalk erosion with above average Lake Ontario water levels 2017.

Gabion baskets (metal wire cages filled with stone), and armour stone (large boulders), are protecting the boardwalk in the Beaches from encroaching lake levels. Further west at Woodbine Beach "Puddlegeddon" is raging on, interfering with volleyball plans although the puddles are subsiding.

Woodbine Beach Puddle-geddon, Puddle-pocolypse, Puddle-o-rama, Puddle-nado, Puddle-duddle ... umm its a puddle and
Lake Ontario levels are a whopping 4 centimetres higher than a previous maximum monthly value.
While you could say water levels are high for volley ballers who have been playing in the Woodbine Beach league for almost 20 years, the levels are only 4 centimetres above the previous May maximum. So it is not unexpected that in a 100 year monitoring record, you exceed an earlier maximum every so often. That is what statistically is supposed to happen with observations of natural systems. Today's Lake Ontario levels are not significantly above the maximum values 65 years ago in 1952 or 44 years ago in 1973.

***
Need up to date Lake Ontario levels 24-7? You can call these numbers to get the current reading, and the maximum and minimum in the past 12 hours. That will include any short term effects from wind set-up (seiches) that tilt the lake higher on one side than another cool. Here are the numbers:

Toronto - (416) 868-6026
Kingston - (613) 544-9264
Burlington - (905) 544-5610
Cobourg - (905) 372-6214
Port Weller - (905) 646-9568

Remember to add 74.2 metres to he number Max Headroom tells you on the phone. He's no Siri or Alexa but you can get the level in English or French.

***
You want more Great Lake real time water level information like the ones above? Call these numbers:

The Canadian Hydrographic Service operates a network of announcing gauges at its stations on the Great Lakes and St. Lawrence River. The following stations can be accessed by telephone at the number listed:

Lake Superior
at Thunder Bay - (807) 344-3141
at Rossport - (807) 824-2250
at Michipicoten - (705) 856-0077
at Gros Cap - (705) 779-2052

St. Marys River
above the lock at Sault Ste Marie - (705) 949-2066
below the lock at Sault Ste Marie - (705) 254-7989

North Channel
Thessalon - (705) 842-2215
at Little Current - (705) 368-3695

Georgian Bay
at Parry Sound - (705) 746-6544
at Midland - (705) 526-6413
at Collingwood - (705) 445-8737

Lake Huron
at Tobermory - (519) 596-2085
at Goderich - (519) 524-8058

St. Clair River
at Point Edward (Sarnia) - (519) 344-0263
at Port Lambton - (519) 677-4092
Detroit River
at Amherstburg - (519) 736-4357

Lake Erie
at Bar Point - (519) 736-7488
at Kingsville - (519) 733-4417
at Erieau - (519) 676-1915
at Port Stanley - (519) 782-3866
at Port Dover - (519) 583-2259
at Port Colborne - (905) 835-2501

Lake Ontario
at Port Weller - (905) 646-9568
at Burlington - (905) 544-5610
at Toronto - (416) 868-6026
at Cobourg - (905) 372-6214
at Kingston - (613) 544-9264

St. Lawrence River
at Brockville - (613) 345-0095
above the lock at Iroquois - (613) 652-4426
below the lock at Iroquois - (613) 652-4839
at Morrisburg - (613) 543-3361
at Cornwall - (613) 930-9373
at Summerstown (Lake St. Francis) - (613) 931-2089

***

Lake Ontario Water Level Update May 2017 

The May water level bulletin in out at this link. It shows we finally broke the record for maximum recorded Lake Ontario water level for May (see chart below). As of May 10 there was no record breaking - as noted in the Environment and Climate Change Canada LEVELnews:

"By the end of April, Lake Ontario had risen to levels that haven’t been seen since 1993, and reached near record levels in the first week of May. By May 10 the daily average Lake Ontario water level was 75.80 m, only 2 cm below the highest level ever recorded (1918–2016) at the beginning of June 1952."

Lake Ontario water elevation
Lake Ontario Water Level
Near Woodbine Beach in Toronto's Beaches neighbourhood, the shore erosion has caused the boardwalk to now be fenced-off. Beyond the armour stone, gabion basket and rip rap revetement that has protected some portions of the boardwalk, the shore has washed away and the boardwalk is undermined, suspended and sagging, hence the barriers:

Lake Ontario Erosion Boardwalk

It makes you wonder what is more effective and reliable, the grey infrastructure in the distance (conventional Armour Stone, gabion baskets (not visible below the surface stones), "rip rap" limestone, or the softer treatment of green infrastructure soil and roots in the foreground that has all washed away due to the force of high water and waves. Basically, the boardwalk damage happened beyond where the conventional grey infrastructure ended, where the green infrastructure failed. This experience suggests that old-fashioned grey infrastructure is more reliable and effective at erosion protection than softer revetment. Certainly the green part of the shore was robust for low lake levels and erosion forces, but not strong enough for above average conditions like we see in Spring 2017 on Lake Ontario.

******

June 24, 2017 Update:

The erosion damage restoration (two layers of armour stone) has been installed along the boardwalk and will provide future erosion protection ... because water level records are made to be broken.


And further west Woodbine Beach has been drying up, and volleyball has returned to larger areas (in the background) now that Lake Ontario water levels are returning to their normal lower elevations. But there is still some evidence of spring 2017 Puddlegeddon.


Prime Minister Trudeau Makes False Statements on Extreme Weather - Says 100 Year Storms Happening Every Few Years Due To Climate Change - Contradicts Environment Canada Scientists and Published Research

Point-Gatineau Flooding in May 1974
Below are my comments sent today to iHeartRADIO given PM Trudeau stated that:

"The frequency of extreme weather events is increasing, and that's related to climate change," the prime minister said. "We're going to have to understand that bracing for a 100-year storm is maybe going to happen every 10 years. Or every few years."

Prime Minister Trudeau states storm frequency is increasing
and ignores issues of land use planning in historical floodplains
when trying to explain flooding in Gatineau in May 2017.
****

Prime Minister makes false statements in the news article:

http://www.iheartradio.ca/cjad/news/was-climate-change-responsible-for-the-floods-1.2603124

Environment Canada scientists has published rainfall trends in Atmosphere-Ocean in 2014 indicating that we are not having more extreme weather, or more frequent 100-year storms. This is link to the journal abstract which states that " The decreasing regional trends for the 5- to 15-minute duration amounts tend to be located in the St. Lawrence region of southern Quebec and in the Atlantic provinces" :

http://www.tandfonline.com/doi/abs/10.1080/07055900.2014.969677?src=recsys&journalCode=tato20

The misconception that storm intensity or frequency is increasing can be traced back to disproved statements by the insurance industry that confused predictions with past observations as clearly shown here:

https://www.slideshare.net/RobertMuir3/storm-intensity-not-increasing-factual-review-of-engineering-datasets

This work exposed that the media has misreported the facts in the official federal Engineering Climate Datasets. This data - used by engineers to design infrastructure across the country - shows for example that there are twice as many statistically significant DECREASING extreme rainfall trends as increasing ones in southern Ontario. This is the official federal data. My work with Advertising Standards Canada over the past 1 1/2 years has corrected false advertising that storm intensity is increasing. The Prime Minister should educate himself on facts and data before making false statements on storm frequency. Environment Canada has often corrected false reporting by the insurance industry on this topic, for example CBC reporting:

http://www.cbc.ca/news/canada/windsor/more-than-half-of-homeowners-insurance-claims-stem-from-water-damage-broker-says-1.3291111

Or recent reporting in Canadian Underwriter:

http://www.canadianunderwriter.ca/insurance/new-ibc-flood-model-shows-1-8-million-canadian-households-at-very-high-risk-1004006457/

As Environment Canada states regarding the insurance industry "flub" that 40 year storms are happening every 6 years:

Associate Editor’s Note: In the 2012 report Telling the Weather Story, commissioned to the Institute for Catastrophic Loss Reduction by the Insurance Bureau of Canada, Professor Gordon McBean writes: “Weather events that used to happen once every 40 years are now happening once every six years in some regions in the country.” A footnote cites “Environment Canada: Intensity-Duration-Frequency Tables and Graphs.” However, a spokesperson for Environment and Climate Change Canada told Canadian Underwriter that ECCC’s studies “have not shown evidence to support” this statement.

So nobel prize winning scientists have been making up a 'weather story', and the PM has been repeating it.

Many events that are now claimed to be unprecedented and due to climate change are in fact commonplace from a statistical point of view. Even the GO Train flood in Toronto at 2013 was not unprecedented - there was a larger flood 6 weeks before that missed the trains because it happened at night:

http://www.cityfloodmap.com/2015/12/stranded-metrolinx-go-train-avoidable.html

The same train was stranded in the same spot in 1981 when there was less pavement in the Don River watershed and less runoff, as shown in this photo:

http://www.cityfloodmap.com/2017/05/go-train-flooded-in-1981-too-media.html

Engineers, hydrologists, watershed managers, hydraulic engineers/modellers can explain flooding by increased hydrologic stresses (more pavement and more runoff). This is quantifiable and indisputable - here is some example mapping / calculations to show that for Toronto area watersheds:

http://www.cityfloodmap.com/2016/08/urbanization-and-runoff-explain.html

Mississauga-Toronto Flooding in 2013? Burlington flood in 2014? Climate change or a heck of a lot more pavement? Here are some maps to show the dramatic increase in pavement since the mid 1960's in those areas ... and the creeks are not any bigger than they used to be to convey the runoff:

http://www.cityfloodmap.com/2016/08/urbanization-runoff-overland-flow-and.html

Important public policies are being created based on mis-reported rainfall trends. This includes expensive climate mitigation plans and taxes to deal with rainfall intensity increases that have NOT occurred. While cheese-eating high school science teachers are making theoretical connections between temperature (global warming) and water vapour holding capacity/extreme rainfall, the real scientists like those at MIT or Columbia are studying the real science and saying these guesstimates of more extreme weather due to higher temperatures are not playing out in the real observations. This is recent paper on that topic:

http://www.ldeo.columbia.edu/~clepore/publications_pdf/grl52319.pdf

Robert Muir, M.A.Sc., P.Eng.
Toronto

***

PS - CBC has a nice summary of recurring flooding in Quebec since 1928 at this link

CBC has another great summary from @JudyTrinhCBC showing that this is about poor land use planning decisions (buildings in high risk zones) - 75 % of buildings has a 20% chance of flooding every year being in the 20-year floodplain. Thanks Judy for your stats:

Stats on homes flooded from @ville_gatineau
0 -20 year flood zone: 1428 properties (75% of total) - 20% chance of flooding every year
20 -100 year flood zone: 390 properties - 1-20% chance of flooding every year
outside 100 year flood zone : 70 properties - less than 1% chance of flooding every year

So Prime Minister Trudeau tells us that the storms that affect less than 4% of the properties will happen more often. How about insight on why the other 96% of properties flooded? 

GO Train flooded in 1981 too. Media misses mark suggesting new normal for extreme weather and flooding.

GO Train flood 1981
Stranded GO Train on Richmond Hill line in 1981 in Don River flood plain.
Does this stranded GO Train in the Don River valley look familiar?:

It should. The same thing happened on July 8, 2013 in the same place.

Back when you were rocking to Queen/Bowie Under Pressure for the first time, Metrolinx was getting to know the flood risks for the Richmond Hill line that started in the late 1970's. These rain line flood risks were documented in the flood inquiry report for Premier Davis.

GO Train flood 2013
Stranded GO Train on Richmond Hill line in 2013 in Don River flood plain.
Fast forward to May 28-29, 2013 and there was a bigger flood in the same place. But it happened at night so no trains, no issue.

Fast forward a bit more to July 8, 2013 and we get this: another stranded GO Train in the same place. Exactly the same place? Wow!

Hello McFly! It's Back to the Future. Too bad GO Trains do not fly away like modified DeLorians do.

Metrolinx had to explain the 2013 incident as an unprecedented event. In fact, it was not unprecendented flooding, or rainfall, but unprecedented judgement to not monitor flood levels at the Todmonden river gauge beside the tracks. A sensor has been in place since 1962 and real time sensors were in place online for years (e.g., TRCA Todmorden gauge).

Under pressure no doubt to explain how known safety risks could be ignored for its workers and passengers, Metrolinx would take a page from Milli Vanilli and 'Blame it on the Rain".

Climate change, or extreme rainfall, is a  quick and easy scapegoat for everything that has gone wrong in flood risk management or municipal drainage design over the past 50 to 100 years. But it does not explain incidents that should be managed as well-known operational risks. So 2013 was a big year for 'Blurred Lines", both for Robin Thicke and also for evidence-based, data-driven reporting on flood risk factors.

Today there is widespread misreporting that water level sensors were installed on the Don River after the flash flood of 2013. Perhaps extra sensors have been installed? The truth is that they have been in place for a long time.

If we are going to have effective solutions to flood risk mitigation, we have to accurate in characterization of flood causes, whether it was deficient Keating Channel dredging in the early 1980's or operational decisions in 2013. Otherwise we will "Blame it on the Rain" like Milli Vanilli and concoct misguided solutions to problems that do not exist. Solutions that could be worse than useless and miss real effective opportunities for risk mitigation.

****

PS - the maximum short term rainfall intensity recorded at the long term climate station / rain gauge in downtown Toronto was in 1962 (22.4 mm over 5 minutes). It caused widespread flooding even when the city was not a fully developed or intensified as it is now. Flooding blocked roads and in my neighbourhood there were hundreds of flooded basements as well:


So there is not really a new normal for rainfall and flooding, just more of yesterday's extremes, accentuated with 24-hour cable news, 24-7 weather reporting, and cell phone videos to capture every popped manhole, soggy underpass, or puddle that occurs in a big storm.