Tuesday, October 25, 2016Overcast 9°C

Don River overflows, subway floods in Toronto

Posted by Chris Bateman / June 25, 2014

toronto ttc floodIt's raining again, and that means another round of weather-related chaos for Toronto and the GTA. At time of writing, the Don Valley Parkway is underwater south of Bloor, as are southern parts of Bayview Ave and the GO rail line. There are pockets of localized flooding across the city and parts of the subway system are still drying out from an earlier influx of water.

Toronto Hydro is reporting at least seven separate outages, four of them in a band from Northern Etobicoke through North York into Scarborough, just south of the 401. Downtown, 3,500 customers are in the dark north of the Danforth, south of O'Connor, between Pape and Donlands. Lights are also out in an area bound by St. Clair, Bathurst, College, and Ossington and in parts of Cabbagetown.

A map of the outages is available here.

At one time, both Lawrence and Wilson subway stations were partially underwater (there was a scenic waterfall at the former,) though the TTC is now reporting full service has resume one Line 1 (that's the Yonge-University-Spadina line.)

The rain, though not particularly heavy, was deposited by a slow-moving storm system that made its way south over the city. The downpour started in earnest around 9 p.m. and rain is still lingering close to the lake. Expect tomorrow to be humid. Best skip the trails in the Don.

The special weather statement issued by Environment Canada has now been cancelled.

Here are the best pictures of the evening's action.

Chris Bateman is a staff writer at blogTO. Follow him on Twitter at @chrisbateman.

Image: James Bingham/Twitter



Leftist / June 26, 2014 at 03:41 am
Keep leasing SUVs for $399 a month and save the planet!
Jon / June 26, 2014 at 06:55 am
YEAH! My garden was flooded, were all going to get grocery gift cards from Kathleen Wynne!
Editor / June 26, 2014 at 09:06 am
Hydro, not Hydo.
DonutGobbler / June 26, 2014 at 09:07 am
justice for justin bieber
W. K. Lis / June 26, 2014 at 09:11 am
Nice water feature in the subway station. Any chance of making it permanent?

Childish / June 26, 2014 at 09:26 am
we wasn't readdddyyyyyyyyy!
W. K. Lis / June 26, 2014 at 09:28 am
Don't worry about climate change. The federal government is cutting Environment Canada's (which includes the Weather Office) budget. With less money spent, they expect less storms, apparently.
Jacob / June 26, 2014 at 09:47 am
I can't wait for them to "re-naturalize" the mouth of the Don. It's supposed to prevent the flooding by letting the water flow out the way it's supposed to.

Unless Rob Ford tries to sideline that again for his rich land development buddies.
Token / June 26, 2014 at 09:58 am
The electric presto machine is down do to flooding and I have no tokens......!
Gus / June 26, 2014 at 10:01 am
Due to the recent rain storm and flooding we've pushed back the Presto implementation until 2025
StEC / June 26, 2014 at 10:32 am
Global Warming + Toronto's Growth Boom = INFRASTRUCTURE NIGHTMARE!!!

Seriously... Toronto needs to get their infrastructure in order fast or this world class city is gonna sink to the bottom of the ranking charts real quick! Sewers & the electrical grid need millions upon millions invested to handle the growth and changing weather. Next up the TTC needs tons of money to update & grow to handle the growth. Then the crumbling roads could use some cash!
Alyssa replying to a comment from Leftist / June 26, 2014 at 10:47 am
While climate change does have a little to do with it 793 mm/yr precipitation in Toronto('61-'91) vs now, 831 mm/yr('81-2011), around 4.5% increase over the last 30 years, the greater issue is land use change coupled with fairly old designs of the 50s and 60s before stormwater management took off and TRCA brought in some pretty significant changes to how watersheds are managed.

If its one thing I want to see discussed in the mayoral elections, it's infrastructure and flood management.
Winter Soldier replying to a comment from Editor / June 26, 2014 at 11:01 am
Hail Hydra.
Alyssa replying to a comment from You're not a genius / June 26, 2014 at 11:16 am
Actually it can be both - some of the most serious flooding events were as a result of low intensity but long duration storms - ex: Hurricane Hazel, which resulted in loss of life and millions in damage was 200mm/24 hrs, which is no more than 8mm/hr. That might not seem that much - but that rainfall sustained over a day or more results in incredible volumes.
Compare that with say, a cloud burst, which can have very high intensities over short periods of time: a 2-yr storm is 88.2 mm/hr for T.0; the 10min, 100-yr storm is 250 mm/hr!!

Rate and volume are both significant, and so are the initial conditions. If the it has been raining for days and the ground is saturated, your runoff will be greater and you can get localized flooding with very low intensity. So you can see that an extra 38 mm - applied over the 600 km^2 of land results in an additional 23.9 M m3 of volume a year, which has to make its way through the watershed.

tl;dr - many factors contribute to flood.
McRib / June 26, 2014 at 11:54 am
it rained last night? Man, i need to cut down on my drinking while watching the world cup.
Abracadabra / June 26, 2014 at 03:50 pm
Toronto's subway system has the ambiance of a dungeon at the best of times. :-/
GRAARG replying to a comment from You're not a genius / June 26, 2014 at 04:07 pm
There is no good data to say frequency or intensity of storms is increasing due to AWG. Yes, you see it cited in the press and you see it in some papers. But the best source, the most peer reviewed source is the IPCC itself and here is their take on more frequent/more intense storms:

“In summary, there continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale”

IPCCs views on hurricanes, tornado's etc the same. While there are some hypotheses about this being an output of AWG, the data does not support it, despite what the City of Toronto says.

Reg replying to a comment from Abracadabra / June 26, 2014 at 04:09 pm
Subway systems flood all over the world even in your cherished NYC. There isn't much way of stopping it as I'm sure you're all aware water will always run down and what's the lowest point, the subway.

The city should be looking at the roads and above ground rail lines that keep flooding, they can build areas up so they will remain higher then the water level.
Reg replying to a comment from Reg / June 26, 2014 at 04:15 pm
I agree with myself! Open subway tunnels and staircases cannot be closed off or water proofed to stop the volume of water from rushing in.

THE QUESTION IS why was Environment Canada so wrong in the past few weeks with the weather. No heads up on the storms or the 3 tornado's that touched down last week, yesterday they said chance of light rain for the evening then we get flooded in a major downpour? How can they be so wrong? If they were able to give the heads up people could get prepared. I know that there are freak acts of nature but come on, last night was a megastorm system and they are environment Canada not some public access TV station with a weather reporter.
stopitman / June 26, 2014 at 05:35 pm
Ontario: the place where you build highways in valleys and are surprised when they are flooded by the river beside them.

Case studies: Don Valley Parkway and Red Hill Valley Expressway (Hamilton).

At least the railways have good excuses: 150 years ago they didn't care and they can't make sharp turns or take steep hills. Road engineers are just stupid.
RobFord'sChinFat / June 26, 2014 at 11:28 pm
Wooooooooooo let's keep paving Toronto... who cares about the Toronto Ravines...
Rob M / March 19, 2016 at 02:11 pm
Alyssa you are right-on when it comes to old designs - it is the lack of pre 1980's overland drainage grading of roads that is flooding old neighbourhoods. I've correlated past flooded basements with lost rivers where this extreme storm drainage overland flow capacity has been lost (filled in):


This neighbourhood has that overland drainage problem too:


Some infill sites in Toronto can fill in overland flow paths because it is not regulated in the TRCA O.Reg.166/06 and so it can't be protected/managed the same way a regulated river flood plain can.

Paving the Don watershed from 15% in the 1950's to 90% now is also what causes higher flood risks in both the rivers and beyond the valley.

GAARG is right on the global flood trends. Add to that the lack of nationally trends when it comes to extreme rain intensity:


And even decreasing rain intensity trends in southern Ontario using the same Environment Canada engineering climate datasets (version 2.3):


And so you have to go back to Alyssa's point about runoff volumes increasing as a key factor in flooding, because rain is NOT increasing. In fact the extreme value 100 year intensities for all durations have been decreasing at the Bloor Street climate station since I started working in this field 25 years ago (1990 data, 2003 data, 2007 data):


The story that rain intensity is increasing can be traced to the Insurance Bureau of Canada's and Institute for Catastrophic Loss Reductions publication "Telling the Weather Story". It has just been revealed that they 'made up' their data, having substituted a theoretical bell curve shift in probability density function for for real Environment Canada data. Here is the shocking sad truth:


Toronto also has some flakey reports like the one from SENES that underestimates today's rain by half and then predicts it will double - more sad sad bad bad science. They reported today's 1-hr 10 year rain is 20 mm when in fact it was double that 26 years ago.

The Don River is meant to overflow frequently, especially if the Keating Channel is not dredged - which it has not been fully for the past years because the Cherry St bridge is broken and the dredge can't get through. Its an operational problem, not climate change.

Maybe Wynne's cap and trade can fund fixing the bridge and dredging the channel.

Maybe it will fund a flood warning system for Metrolinx who ignored the long-standing risk of the rail line flooding (something we've all know about since the flodo inquiry report for Premier Davis in the early 1980s):


Other Cities: Montreal