Audit finds flood hazard mapping behind schedule, doesn’t account for climate change

OTTAWA — Federal efforts to map parts of the country facing the highest risk of flooding are not on track to finish by the 2028 target date and don’t account for the effects of climate change, Canada’s environment watchdog said in a new report.

It was one of five reports issued by environment commissioner Jerry DeMarco and auditor general Karen Hogan on Monday — which also included probes of Canada’s avian flu response, First Nations funding, the climate resilience of federal assets, and how well the government accommodates accessibility needs in the public service.

The flood mapping report found the flood risk awareness portal under development at the Public Safety department does not consider how climate change is affecting flood patterns.

“Flood hazard maps must integrate climate change projections; otherwise, the data are not accurate enough to guide long-term decisions, such as where to build homes or develop infrastructure,” the report said.

The risk ratings were generated using present-day assumptions and the audit found that because the government used a private sector contractor to create a proprietary system, it was not able to adjust the model.

The audit also looked at efforts to map high-risk flood areas at the Natural Resources department.

The department identified 200 areas at high risk of flooding in 2022 but the audit found it did not monitor whether the mapping projects actually covered those priority areas.

As a result, the audit said, less than half of the 131 mapping projects cover the high-risk areas identified after that 2022 analysis. Only 11 of those maps had been posted to the Canada flood map inventory.

Flood relief efforts cost the federal government an average of $230 million a year between 2016 and 2025. That average cost is rising as a result of climate change and population growth.

The national risk profile found about 80 per cent of highly populated areas of the country are at least partially in flood hazard zones.

DeMarco is recommending the government create user-friendly, interactive flood maps to ensure people can prepare.

The audit notes federal investments in homes and infrastructure, “including those announced in Budget 2025, could be planned and designed with climate readiness in mind by using reliable and actionable flood hazard information.”

The audit also says the government needs to work with provinces and territories to monitor high-risk areas.

The government says it has accepted all recommendations.

This report by The Canadian Press was first published May 4, 2026.

Sarah Ritchie, The Canadian Press