Cities across the Greater Toronto Area are emerging as Ontario’s most flood-prone communities, with Ajax, Mississauga, Toronto, and Brampton ranking among the top five at-risk municipalities in a new MyChoice Insurance report. Ajax leads the list with a near-maximum flood risk score of 4.6 out of 5, followed closely by Ottawa, Mississauga, Toronto, and Brampton.
The report highlights that these cities share common risk factors — dense populations, rapid urbanization, and sprawling infrastructure — all of which amplify their vulnerability to extreme weather events. This year alone, flash floods across Toronto and southern Ontario caused more than $940 million in insured losses, while severe weather events in 2023 racked up $3.1 billion nationwide. In Brampton, spring flooding forced the closure of a lake trail and caused extensive damage to a wetland project.
Despite the risk, the report warns that investment in flood prevention is uneven. While Toronto, Ottawa, and Mississauga receive substantial funding for flood defences, Ajax and Brampton appear to lack comparable government support, potentially leaving critical gaps in protection.
The study also underscores the financial strain on homeowners, noting that many face soaring insurance premiums and must purchase additional sewer backup and overland water coverage, as basic plans rarely offer sufficient protection.
With insured losses from extreme weather reaching a record $8.5 billion in 2024, the report calls for a more comprehensive and equitable flood mitigation strategy across Ontario to keep pace with the escalating climate threat.