Where Edmonton's flood plan stands after this summer.
We started building this in 2019. Here is the current position and the decision I want your help with.
The wettest summer Edmonton has ever recorded
Records here go back to the 1880s. Nothing in that file looks like this June and July.
June brought over 260 mm and broke a 112 year old record. July reached 260.7 mm against a July record of 282 mm set in 1901.
The long record
Start with the last ten years, then widen it out. The further back you go, the clearer it gets that 2026 is not a normal wet year.
The Dry Decade
Widen the chart to 25 years and the point appears. The average for 2005 to 2024 is 373 mm, well under the long run figure of 439 mm. Until this year we were living through one of the driest stretches Edmonton has recorded. Then the line went vertical.
Where the year could finish
About 90 mm more precipitation makes 2026 the wettest year Edmonton has ever recorded.
The Heritage Day long weekend
More settled than the last few weeks, with one wet day in the middle of it.
Sunday is the one to watch. The high drops 13 degrees from Saturday and brings 15 mm onto ground that is already saturated. Monday and Tuesday look dry. Forecast as of Friday July 31.
Annual totals from 1880 to 2024 are NOAA records for the Edmonton stations, published by Extreme Weather Watch. Monthly and seasonal figures for 2026 come from Environment and Climate Change Canada. The year to date total counts winter snow as well as rain. The gauge sat in the city to 2014 and at the International Airport from 2015, so recent years read a little low against the older record. 2015 is left out because that year's data is incomplete at source.
For scale, Edmonton's 511 mm through July 26 out-rained New Orleans at 455 mm, Houston at 278 mm, Tampa at 248 mm and Calgary at 121 mm over the same stretch.
In plain English
Two months brought more rain than Edmonton usually gets in a whole year.
And the ten years before this were unusually dry, which is part of why it feels so strange. The ground and the pipes were used to less, and then got a great deal more.
Why a small rain now causes a big flood
A dry sponge soaks up a spill. A soaked one pushes it around the counter. Our ground is the soaked sponge, and the reason is what Edmonton is built on.
What is under your street
When the glaciers melted, a lake covered this whole area and left metres of fine silt and clay behind. Whitemud Creek is named for it. Water stops at that layer instead of draining down, then travels sideways, often along the trenches dug for pipes.
The Soaked Sponge
Saturated ground is no longer absorbing water the way it normally would. That sends far more runoff into the drains, which is why underpasses flood and roads wash out after storms that would once have been ordinary. Storms have also come so close together that the ponds and pipes never fully drain before the next one arrives.
How a sinkhole forms
A sinkhole more than 10 metres deep opened in Lauderdale on July 13. Roads have also collapsed in Starling.
What the road does next
The damage from a soaked summer arrives on a schedule. Here is the sequence, and it runs through to next summer.
The same stretch of road, four times
Wet ground freezes and ice takes up more room than the water it came from, so the pavement lifts. When it thaws, the road drops back and cracks. Next summer the clay dries and shrinks, and ground that swelled all winter settles unevenly.
None of this stops cleanly at a season boundary.
When to expect each kind of damage
Potholes are not only a spring problem
Filling potholes is a year round job in Edmonton, and spring is simply the busiest stretch. Pothole season normally starts in mid to late March, but a winter with frequent freeze and thaw swings pulls it into January. Crews filled almost 6,000 in a single January during one such winter, and one recent year ran about 30 freeze and thaw cycles before March had finished.
The mechanism is not really the spring drop. Water gets into small cracks in the asphalt, freezes, and expands. Every swing above and below zero does it again. A wet autumn puts more water into more cracks before the first freeze, which is why this particular winter is worth watching.
Alberta measures the thaw at 70 frost probe stations and declares spring when it reaches 25 cm deep. Winter weight limits start when frost passes about a metre. Those readings, not the calendar, set the dates above.
In plain English
Think of a kitchen sponge that is already full. Pour more water on it and none of it goes in. It just runs off the sides. That is our ground right now.
So a storm that used to be nothing at all now floods a road, because the water has nowhere to go but sideways and downhill.
And the repair bill does not all arrive today. Some of it shows up in the spring, when the ground thaws and the pavement cracks.
So what has actually been built since 2019?
The Stormwater Integrated Resource Plan is a $1.6 billion plan run by EPCOR and approved by Council in 2019. Its priorities were set by a public survey.
Six years in, here is the money
Progress to date (please let me know if I missed any!)
A dry pond is a park or ball diamond that quietly fills during a storm and drains in about a day. Water goes there instead of into your basement. Thirty one sites are proposed.
Does this work? It has already been tested.
Mill Woods flooded badly in 2012. Residents formed a flood mitigation task force, and over the following decade the stormwater system there was rebuilt. Existing dry ponds were expanded and new ones were added.
In June 2023, an intense rainfall hit that was comparable to the one in 2012 (with 89.9 mm falling over four and a half days). The upgraded system worked as designed. Homes that flooded in 2012 did NOT flood in 2023. This is an example of why finishing the rest of the plan is so important.
The five things the plan does
- Slow. Dry ponds, rain gardens, tree soil cells and porous paving. The largest part of the plan.
- Move. Bigger sewers and tunnels, and splitting combined storm and sewage pipes.
- Secure. Flood proofing for 6,000 high risk properties, with outreach to 40,000 more homes.
- Predict. Sensors at ponds and underpasses feeding a live dashboard, weather radar alongside it, and gates that open and close on what those readings show.
- Respond. Barriers and diversions when a storm hits, run with the City's emergency team.
Edmonton went first on this
The plan received a Canada's Clean50 Top Project Award and a second as an Individual Honouree. The Institute for Catastrophic Loss Reduction featured Edmonton's approach nationally. Work with the Canadian Water Network and the Insurance Bureau of Canada made Edmonton a test case for whether insurance flood modelling can guide municipal engineering. Five reports were put in the public domain so other communities could copy the method.
In plain English
This plan has been running since 2019. About $350 million of it is in the ground. The majority of it is not built yet as it continues to roll out.
At the time, I recall not everyone was convinced we needed this. Imagine if we were starting from nothing this July!
Now the part I need you for
In 2019 Council had three speeds on the table. We chose 20 years, because it was the pace households could carry. That decision can be revisited.
Move the finish date and watch the bill
Estimate based on previous reports and numbers.
Stay the course
No change to your billFlood work finishes around 2040. Rates rise only by what is already approved.
Finish by 2035
About $8 to $9 more a monthFive years sooner. Yearly spending rises from about $130 million to $220 million.
Finish by 2032
About $21 to $22 more a monthEight years sooner. Expect more streets dug up at once.
Add heat and drought work
You help set the scaleKeep the flood pace and do more on shade, tree cover, drought planning and wildfire protection. Council sets those priorities for 2027 to 2030 this year.
- EPCOR reports for the plan cost, the $470 million pond allocation, and the $350 million spent.
- Statistics Canada for the rise in construction costs since 2019, about 42 per cent.
- An industry range of 10 to 20 per cent added for compressing a build into fewer years.
- An assumption that homes carry about half the total, spread across roughly 450,000 households.
That last one is the softest assumption and I have asked EPCOR to confirm it. Commercial and industrial properties pay stormwater by lot area too, and they hold large lots. If their share is bigger, every monthly figure drops.
The costed alternatives Council actually saw in 2019 sit in report CR_7054, which is public. I have asked for them.
Send me your answer. One line is enough.
No option selected yet. Choose one above, or just write to me.
Email meTrees and long grass are flood infrastructure
Leaves catch rain before it reaches the ground, and roots open the soil so it can sink in. The tree then draws water back out of the soil, which makes room for the next storm.
Canopy cover, now and the target
Two million trees, moved up twenty years
The City committed to two million net new trees by 2050. A mature tree does far more flood and shade work than a sapling, and canopy takes decades to grow, so Council moved the deadline up to 2030 to get those benefits sooner. The cost is about $114 million, with roughly $48 million expected from Canada's 2 Billion Trees program.
The trees that came down
Storm damaged trees over sidewalks and roads come down before they can fall on someone. Elm wood is removed quickly because it can carry the beetles that spread Dutch elm disease. Replanting is part of the same program.
Naturalization is part of the flood plan
Mown turf has short roots and tight soil beneath it, so rain runs off the surface to the nearest drain, much as it would off pavement. Deep rooted native plants open channels in the soil, and a storm sinks in where it lands instead of reaching the drain all at once.
The same rain on two kinds of ground
Around a stormwater pond it slows runoff before it arrives, filters the water, holds the bank against erosion, and widens the buffer between open water and the places people walk.
What else it does
The plants that come in flower and set seed, which feeds bees, butterflies and songbirds. The height of them gives cover to small animals. Strung together, these patches work as corridors that let wildlife cross a city otherwise cut into pieces by roads. They also cost less to maintain than turf, because they are not mown every week.
Where it happens, and why there
Naturalization goes into places that are difficult or unsafe to mow, and places where it does the most good. Slopes too steep for a mower to sit on safely. Ground too wet to carry equipment. Roadsides where the speed limit is over 70, so nobody has to work a mower next to fast traffic. And the edges of stormwater ponds and dry ponds.
Along a residential fence line the City mows a strip about a metre wide between the naturalized area and the property, where the ground allows it. That strip discourages animals from crossing into yards and keeps tall growth from spreading past the boundary.
It takes years, and it looks rough at the start
Since 2023, a site being prepared is mown short, to about 10 centimetres, at the start of the season. That stage can run a year or two. Then mowing stops and long grass comes in, which is the stage people notice. After that, native trees and shrubs are planted among whatever has returned on its own, and crews keep managing weeds. Years later it reads as woodland rather than a neglected field.
The 2021 pond program
Edmonton has been naturalizing green space for more than 25 years. Since 2014, close to 280 hectares of City maintained parkland have been naturalized or started the process, about 4.4 per cent of it.
In 2021 the City began naturalizing 150 hectares around 148 stormwater ponds. That specific program was paused in 2022, and mowing restarted in some of those areas, while public engagement was done and a new plan developed. The City was clear at the time that the pause applied to that program and not to naturalization elsewhere, which carried on.
Engagement ran through 2022 and 2023 and planting resumed after it. Naturalization is still debated, and some residents want more consultation before planting starts near their homes.
In plain English
A big tree drinks a surprising amount of water. Every one of them takes a share of what would otherwise reach the drain.
Some trees blew down in the storms. Crews are cutting down others that the storms damaged but left standing, where they lean over a sidewalk or a road.
Long grass around a pond has not been skipped. The deep roots pull water into the ground and hold the bank in place. The flowers and seed heads feed bees and birds.
Read this before you assume the province will cover it
Which door your claim goes through depends on how the water got in.
Alberta's Hazard Assistance and Resilience Program only covers damage insurance could not have covered. Because sewer backup coverage is treated as widely available here, that side usually goes through your insurer.
How the provincial program works
- The City applies to the province first.
- The province approves or refuses that application.
- If approved, the City tells residents they can apply.
- Homeowners and small businesses then apply directly.
You cannot apply until the City is approved, so watch for the notice. The City has already filed for June's storms, claiming about $26 million in damage that insurance does not cover, and will file for July by the end of August. The province pays up to 90 per cent of eligible costs.
Something you can do this weekend
If you see a clogged drain and you are comfortable clearing it, go ahead. Pulling leaves and litter off a grate takes a minute and moves water off your street and away from your neighbours. If it needs more than that, report it to 311. Crews are running around the clock, so it may take a little time to reach you.
What to do today
- Call your insurer before you throw anything out.
- Photograph everything, including water lines on walls.
- Keep every receipt for cleanup and repair.
- Report flooding and damage to 311.
- Check whether you carry both sewer backup and overland coverage.
Help EPCOR offers right now
Homes built after 1989 already have a backwater valve. Anything earlier likely does not. Inspections are backed up, so book early.
In plain English
If your basement flooded, phone your insurance company first. Do that before you throw out a single thing.
Take photos, keep your receipts, report it to 311, and book the free EPCOR inspection now because the wait is long.
Thank you
City crews and contractors have worked around the clock for weeks. They have pumped water, chased sinkholes, cleared trees and answered more than 3,000 storm calls.
Calgary activated a mutual aid agreement and sent certified forestry crews north to clear fallen limbs and whole tree blowdowns. Waste and recycling crews followed. Our regional neighbours have stepped in as well. When Calgary flooded in 2013, Edmonton sent 60 volunteer firefighters, heavy equipment, street sweepers and bridge inspectors south, which was the first time either city used that agreement.
Edmontonians checked on neighbours, cleared leaves off blocked drains, reported problems to 311 and cut back water use when asked.
Sources
Here is the information:
Cost figures described as estimates are my own arithmetic from published numbers, with the assumptions stated in Part 4. Anything I could not source, I have said so.