Flash flooding has driven much of Ontario's insured losses this storm season. With loss estimates for the September 2 Toronto storm still to come, brokers have a narrowing window to check which clients carry the optional cover that responds to it.
The September 2 storm dropped 100 to 110 millimetres of rain on parts of Toronto in a single afternoon, submerging vehicles on the Don Valley Parkway and cutting power to 65,000 Toronto Hydro customers at its peak. Gallagher Re has projected insured losses well into the hundreds of millions of dollars, with large hail as well as flooding driving claims.
It followed a series of thunderstorms across Ontario and Quebec between June 30 and July 3, which caused $439 million in insured damage, according to Catastrophe Indices and Quantification Inc. (CatIQ). Ottawa recorded 118 millimetres of rain on Canada Day, breaking its all-time July daily record, and local officials reported more than 4,500 basement floods, including sewer backups and drainage failures.
"Notably, many of these events have featured flash flooding as the main driver for insured losses," said Caroline Floyd, director of CatIQ. She noted that eleven severe convective storm catastrophes had been declared in Canada since June.
Overland flood and sewer backup coverage are optional endorsements in Canada, sold at additional cost and often subject to sublimits. A client without them can face tens of thousands of dollars in uninsured remediation after a basement flood. The source of the water matters too. Ottawa's basement flood count includes both sewer backups and overland flooding, and a client with only one of the two endorsements may be covered for one cause and not the other.
Several Ontario municipalities now offer incentives aimed at the same urban flood risk. Ottawa offers up to $5,000 in flood-prone neighbourhoods for measures such as rain gardens, permeable pavement and soakaway pits. Hamilton, Guelph and Thunder Bay run comparable programs, and Toronto's Green Infrastructure Incentive Program, launching next year, will offer up to $500 toward the professional design of a rain garden or permeable surface.
Insurers do not fund these programs, and whether carriers give credit for such measures at renewal varies. For brokers with clients in flood-prone parts of Ottawa and Toronto, the rebates offer a practical second conversation alongside confirming that overland flood and sewer backup endorsements are in place. It is also worth asking carriers directly whether documented mitigation affects pricing or availability.
"These storms underscore the need for greater investment in measures that reduce flood risk and better protect Canadians from future losses," said Maximilien Roy, vice-president of strategy at the Insurance Bureau of Canada.
