As climate change worries grow, St. John's plans for future big storms

A new report indicates increased risk of flooding in some parts of St. John's, more extreme weather events and climate change concerns grow.

The report, conducted by Stantec Consulting Ltd., looked at the risk for flooding in seven areas across the city, the largest being the Virginia River in the east end.

Tracey-Lynn Goosney, the city's manager of development engineering, said climate change needs to be factored into planning for new infrastructure like bridges, residential subdivisions and other development.

"These things are going to be around for a long time," she said in an interview with CBC Radio's The St. John's Morning Show. "We need to make sure that they're able to withstand these changes."

The report uses climate modelling to predict how climate change will affect flooding events that statistically could happen every 20 or 100 years.

According to the report, a once-in-a-century storm could cause 23 structures, like bridges and culverts to overflow in six of the studied areas. 

"[The city] didn't always use these higher flows, these climate change flows, for design," Goosney explained.

Now, Goosney said, infrastructure is designed with future extreme weather events in mind.

"Public works and engineering will use … this information to make decisions on what infrastructure needs to be upgraded and when," she said.

She said the city has previously done flood risk mapping in major areas like the Waterford River and Rennie's River, both of which have flooded during previous storms.

Goosney also said the study also looks at flooding scenarios under the current climate conditions to help inform emergency planning.

According to a city council decision note, the city will use the report to inform its development regulations.

Goosney said some of the areas in this latest study have active development applications or developer interest.

"It's important that we get these maps, these boundaries, so that we have accurate information for developers," she said.

City council approved the report at a committee of the whole meeting on Tuesday.

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