The Metropolis’s stormwater infrastructure has helped to mitigate the impression of near-record rainfall, demonstrating its function in aiding with defending town throughout excessive climate occasions.
A important, however largely invisible, infrastructure system has helped town from being utterly washed away from a couple of main storms. Stormwater is the rain or melted snow that flows or runs off properties and roads and drains alongside streets, ditches, storm drains, and watercourses into Lake Ontario. The Metropolis’s stormwater infrastructure has helped to mitigate the impression of near-record rainfall, demonstrating its function in aiding with defending town throughout excessive climate occasions.
Over the course of the summer season, heavy rain falling in a brief time period brought about excessive water ranges and localized flooding on roads and alongside creeks, rivers and streams. The July 16 storm noticed greater than 106 mm of rainfall and the August 17-18 storm introduced upwards of 170 mm to some areas in Mississauga.
Whereas some parks flooded, trails washed out, embankments eroded, particles flowed into neighbourhoods, and a few residents skilled property harm like basement flooding or water pooling of their backyards – it might have been worse with out the Metropolis’s stormwater infrastructure actively managing the scenario. It dealt with nearly all of the weird amount of rain on account of its community of underground pipes, designated stormwater ponds, culverts and overland circulate routes alongside roadways.
About Mississauga’s stormwater system
Separate from the sanitary wastewater system, the Metropolis’s stormwater system collects stormwater from properties and carries it to a receiving waterbody. Sustaining this technique lessens the chance of flooding, reduces creek erosion and protects water high quality. That is essential because it protects you, your property, aquatic habitats, wildlife and Lake Ontario.
Initiatives funded by the Metropolis’s stormwater cost, protected flood-susceptible lands downstream throughout the Cooksville Creek watershed.
Further stormwater administration services within the Cooksville watershed have been constructed beneath current parks within the final ten years that help discount of peak flows in giant storm occasions. These embody services beneath Eastgate Park, Sandalwood Park and Mississauga Valley. These enhancements had been key in considerably decreasing the impression of flooding.
Lake Saigon – the stormwater administration pond at Matheson Blvd. E. and Hurontario St. was designed to carry again flows that end in elevated safety of the extra flood inclined lands downstream throughout the Cooksville Creek watershed. Lake Saigon held again 250,000m3 of stormwater, and subsequently diminished the quantity of flooding downstream. This one pond held again the equal of 100 Olympic-sized swimming swimming pools of water from flowing downstream to houses and companies.
These infrastructure enhancements had been key in mitigating the impression of flooding throughout the metropolis, highlighting the significance of the Metropolis’s stormwater cost as a important funding.
The stormwater system serves to safeguard town in opposition to unpredictable storms of this scale, serving to to guard our communities and the lives of residents. Final June, the Metropolis accredited its first Stormwater Grasp Plan, Construct Lovely. The accredited long-term plan will refine the Metropolis’s stormwater program, administration techniques, and infrastructure. It is going to assist the Metropolis tackle points dealing with Mississauga as we speak and, sooner or later, together with flooding, water high quality, and air pollution whereas working to protect our surroundings.
Local weather change and rainfall
With local weather change unfolding, we’ll see storms like this occur extra steadily. Each degree of temperature change, even one degree hotter, can impression our surroundings considerably. This might imply extra widespread flooding with rainfall ranges anticipated to extend in quantity and depth, with extra frequent and intense precipitation. It’s essential that we handle stormwater to scale back flooding danger to your property, decrease erosion of our creeks and restrict the quantity of air pollution getting into Lake Ontario.
This isn’t the primary time Mississauga has skilled heavy rains. On July 8, 2013, greater than 10 years in the past, town skilled a storm the place greater than 126 mm of rain was recorded at Toronto Pearson airport over a stretch of 10 hours. One other recorded storm was in 1954 –Hurricane Hazel, which dropped greater than 200 mm of rain over Mississauga in 24 hours.
Stormwater infrastructure is sized to convey flows based mostly on “peak intensity”. For instance, 50 mm of rain falling intensely over 2 hours is extra prone to trigger points within the city setting than if 50mm of rain fell slowly over 2 days. Along with peak depth, the overall quantity of rain can overwhelm storm drainage techniques. These two components (i.e. depth and whole rainfall) assist to outline storms by assigning a particular return interval. That’s to say, extra intense and better quantity storms happen much less usually whereas much less intense, decrease quantity storms can happen a number of occasions yearly.
The size used for these storms return durations ranges from a 2-year storm as much as a 100-year storm. A “2-year” storm is a rainfall occasion of sure length that has a 50 per cent likelihood of occurring in a given 12 months, so comparatively extra usually. Whereas, in idea, a “100-year” storm has a 1 per cent likelihood of occurring in a given 12 months, so comparatively much less usually. You will need to perceive that whereas these return durations assist us to know the character of a storm, they’re theoretical values. In different phrases, a 100-year storm might happen twice in a single 12 months. It’s simply that it’s much less prone to occur. Rainstorms through the summer season are typically extra localized the place it could solely impression a sure a part of the Metropolis.
Presently, the Metropolis has greater than 1,900 kilometres of storm sewer pipes in its drainage system. If laid out end-to-end, these pipes would join Mississauga to Winnipeg. The stormwater drainage system additionally contains greater than 51,000 catchbasins, 270 kilometres of ditches, 150 kilometres of creeks, and 81 stormwater administration services (together with ponds, underground storage, and Low-Impression Growth services) that assist to gather, drain, and clear town’s rainwater runoff earlier than it enters Lake Ontario, the supply of our ingesting water.
Stormwater cost
The Stormwater Cost has made an actual distinction within the supply of the Metropolis’s stormwater program. It helps with the operations and upkeep of our stormwater techniques together with essential actions like cleansing out our catchbasins. These acquire rain and snow soften to supply property and highway drainage in neighbourhoods, and in addition lure particles, stopping litter and pollution from flowing to our creeks.
The stormwater drainage system is without doubt one of the largest belongings owned and operated by the Metropolis of Mississauga. The 2024 Company Asset Administration Plan estimated a alternative worth of $7.6 billion.
In 2024, we’ve allotted $33.7 million for stormwater enhancements, specializing in tasks alongside Cooksville Creek, Etobicoke Creek, and erosion management initiatives. Since 2016, we’ve invested over $231.5 million in stormwater infrastructure. Our 10-year plan contains a further $340 million for ongoing upgrades and upkeep to reinforce our resilience in opposition to future storms. And, we stay dedicated to continued investments in additional enhancing our stormwater infrastructure to resist future climate occasions like this one. These investments embody stormwater ponds, new pipes within the floor, and repairs to creek and river banks to stop erosion.
2024 Capital funded tasks
Authorized 2024 tasks funded at $33.7 million, which embody:
Mississauga LRT Storm Sewer Enhancements
Malton Drainage Enhancements – Etude Dr. to Justine Dr.
Design for Dixie Dundas Drainage Enhancements by Little Etobicoke Creek
2024 Deliberate building tasks: Creek, erosion management work and stormwater administration facility tasks
Development of a pumping station on the south-east nook of Doug Leavens Blvd and the Lisgar channel
Etobicoke Creek erosion management and rehabilitation (Ponytrail Dr. to Bloor St.)
Sawmill Creek erosion management and rehabilitation (Folkway Drive to Erin Mills Parkway)
McKenzie Park Storm Water Administration Facility
Sheridan Creek erosion management and rehabilitation (Lushes Avenue to behind Fletchers Valley Crescent)
Cooksville Creek enchancment and flood safety and alternative of King Avenue Bridge
Dredging and rehabilitation of Dixie Highway Bus Fast Transit pond
Dredging and rehabilitation of Tomken Highway Bus Fast Transit pond
10 -Yr Capital Plan
2024–2033 tasks to be funded at $340 million and embody:
Design and Development of Pond Dredging and Rehabilitation at Lake Wabukayne & Aquitaine (2025)
Malton Flood Aid Challenge (Etude Dr. to Justine Dr.), together with building of a stormwater field culvert beneath the pedestrian walkway, full reconstruction of the walkway to securely create an overland circulate route, and an upgraded outfall construction and channel in Derry Greenway Park (2025 – TBD)
Dundas & Lakeshore BRT Storm Sewer Enhancements (2025)
Design and Development of Cooksville Flood Storage Facility – Greyshale Park (2027) and Heritage Hills Park (2028–2030)
Dixie and Dundas Drainage Enhancements (2025, 2027–2033)
Development of Sawmill Creek Erosion Management–Erin Mills Parkway to The Collegeway (2029)
Learn the 2024-2027 Enterprise Plan and the 2024 Price range for Stormwater.
The necessity for continued infrastructure funding
Over the following 10-years, the Metropolis’s Stormwater program will construct, increase, and preserve our stormwater system. Will probably be totally funded by the Stormwater Cost. Nonetheless, there’s nonetheless a have to appropriately contribute to the Pipe Reserve Fund to permit for the long run alternative of the Metropolis’s ageing storm water pipes.
The Metropolis is searching for a dedication from federal and provincial governments and is advocating for extra funding to assist bridge the infrastructure hole. That is essential for underlining priorities, corresponding to stormwater infrastructure, which might be important to the protection of our neighborhood.
Study extra concerning the Metropolis’s stormwater program and devoted cost right here.
Learn the 2024-2027 Enterprise Plan and the 2024 Price range for Stormwater.
Watch our stormwater video.
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Metropolis of Mississauga Media Relations
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905-615-3200, ext. 5232
TTY: 905-896-5151
