Sweeping changes mean Mississauga is better protected from major floods: city

Mississauga is better protected today against severe flooding brought about by record-setting rainfall than it was last summer when two “one-in-100-year” storms unleashed their fury, city officials say.

And moving forward, Canada’s seventh-largest city plans to put up an even more effective defence against such damaging weather events as existing infrastructure is strengthened, new practices are introduced and additional staff are brought on board.

“Since last summer, the city has accelerated both planned and new stormwater infrastructure upgrades and assessments to better protect Mississauga neighbourhoods from severe flooding,” the City of Mississauga said in an update this week, one year after the first of two summer 2024 “100-year storms” struck the area.

Combined, the July 16, 2024 and Aug. 17-18, 2024 rainstorms dropped nearly 280 millimetres of rain on Mississauga, officials said.

“These events were unprecedented and impacted many residents. We know that some residents are still dealing with the impacts,” Emma Calvert, the city’s director of infrastructure planning and engineering services, said in an email to INsauga.com. “That’s why, in addition to the city’s annual investment in stormwater management and flood mitigation, Mississauga council directed staff to look into additional actions that can be taken to help mitigate similar flooding in the future and to provide some financial relief to residents.

“As a result, we received enhanced funding and resources to help increase our flood prevention efforts, to speed up some of our stormwater infrastructure upgrades and assessments, and to deliver new residential flood prevention and flood resilience rebates (to residents),” Calvert continued. “Climate change is a reality and it’s here to stay, so we are working to do what we can to be prepared. Since last summer, city teams have advanced and accelerated a number of actions that are helping build greater resiliency into Mississauga’s stormwater system. And while we can never guarantee that floods won’t impact us again, we are doing what we can to try and mitigate the impacts of severe weather events like flooding.”

Mississauga firefighters were out in water rescue boats on July 16, 2024 in this east Mississauga neighbourhood making sure nobody was stranded in cars that were overtaken by flood waters.

Following last summer’s severe floods, city council approved an “action plan” developed to ensure Mississauga’s stormwater system “can continue to manage the intense storms and accompanying rainfall that are a reality of climate change,” the city said.

The action plan identifies three goals:

• Implement flood mitigation initiatives through capital projects and maintenance operations.
• Hire additional staff to monitor and maintain the stormwater system.
• Launch financial relief programs for residents impacted by flooding.

Helen Noehammer, Mississauga’s director of works operations and maintenance, said the city has stepped up efforts in a significant way to protect against flooding.

“Our day-to-day operations focus on addressing issues within the stormwater system proactively so that it can perform as designed when it rains,” she said in an email to INsauga.com. “Since last summer, we’ve increased our inspections and maintenance activities to further mitigate the risk of flooding. City staff also routinely participate in training and exercises to prepare for severe weather events.”

Noehammer added that when extreme rainfall hits Mississauga moving forward, the city has an Incident Management Team ready to “swiftly coordinate actions needed to address areas experiencing flooding.”

A car is surrounded by rising flood waters on Queen Frederica Drive in Mississauga’s east end last July 16.

Specifically, the city says key projects currently in progress to upgrade the stormwater system include:

• Land acquisition for the Dixie-Dundas Flood Mitigation Project (neighbourhoods near that major intersection were hard hit by flooding last summer).
• Upgrades to the Historic Malton Village storm sewers (also hit by flooding last year).
• Inlet stormwater upgrades near Greenpark Crescent (Mavis Road and Highway 403 area).

Key projects to upgrade the stormwater system that have been completed include the installation of:

• A 1.2-metre temporary floodwall along Little Etobicoke Creek.
• A storm outfall inline check valve in the stormwater system along Cooksville Creek.
• A trunk sewer inlet upgrade near Tonolli Drive, north of The Queensway.

More people hired to monitor stormwater system

To improve maintenance of the city’s stormwater system, officials said more staff were hired to bolster efforts.

“To improve storm sewer inlet and outlet assessment and maintenance, the city increased the number of staff to enhance the program. These assessments allow staff to identify what infrastructure requires clearing or repair to ensure that stormwater can flow freely,” the city said. “As part of this work, a digital dashboard was created to automatically track and monitor the status of the inlet and outlet assessments in the system as well as any required actions.”

From that work, city officials added, more than 1,300 inlets and outlets in the stormwater system were identified for regular assessments throughout the city. Another 21 locations were added to the list of priority inlets and outlets, bringing the total number of priority locations to 70 and counting, officials said.

“To address service requests and emerging sewer maintenance needs, pipe inspection robots with CCTV cameras are used to inspect pipes and identify damage and blockages that need to be removed,” city officials continued.

Service level improvements include:

• Assessment and clearing of inlets and outlets completed every month, instead of twice a year in the spring and fall.
• Assessment and clearing of priority inlets and outlets completed before and after every significant rain event and at a minimum of once per week.
• CCTV sewer inspection and flushing completed every five years, instead of every 10 years.

(All photos: Mississauga Fire and Emergency Services X)