Insurance companies are warning that some municipalities across Canada may no longer be insurable for water damage if they do not take part in a risk-assessment program.

The Insurance Bureau of Canada is asking municipalities across the country to assess their infrastructures to determine if they could hold up in future storms.

Lower Westmount is one of many areas around Montreal where homes were flooded after nearly 80 millimetres of rain fell within an hour on May 29.

Residents in Montreal and Thunder Bay, which were hit by the same weather system, have made more than $200 million in insurance claims in recent months.

Heavy rain storms in late May accounted for the damage.

Bernard Marchand, an analyst at the Insurance Bureau of Canada, said water damage accounts for about 50 per cent of all home insurance claims. These claims have doubled in the last five years.

Cynthia Lulham, a city councillor for Westmount, said the city is looking at putting a retention basin in the area, but said the city will need help from other governments to make it happen.

"We will need federal money and provincial money to be able to build infrastructure such as retention basins and the like that are necessary," she said.

The Quebec Federation of Municipalities said many towns and cities need major upgrades to their sewer systems, but most don't have the necessary funding.