Fredericton plays long game with flood mitigation

Fredericton plays long game with flood mitigation

The City of Fredericton's flood mitigation strategy can be described as a steady process but not necessarily a quick one, according to an engineer for the city.

"It is a long-term process and, to be honest, 10 years from now we'll still be working on this, and 15 years ago and 20 years ago we were working on this," said Sean Lee, Fredericton's assistant director of engineering and operations.

"So it's something that you need to keep working at as you go, year after year."

Lee said there's no "line item" in the city's budget allocated to flood proofing.

Instead, the city is building flood-mitigation into existing infrastructure-renewal projects, taking a more piecemeal approach.

"What we've been doing is over the past 20 years or so, as we've been moving forward when we're doing an infrastructure renewal product, we're building resilience into that project," said Lee.

"If we're doing a project and a road needs to be raised … we raise that road at that time. If the pipes aren't big enough, we'll increase the size of the pipes of that time."

Floods more common

In just over a decade, the city has experienced three severe floods, in 2008, 2018 and 2019.

All three floods had a significant impact on both public and private infrastructure in the city, closing numerous roads and flooding basements.

In addition to city efforts to mitigate flooding, Lee said private developers have also been flood-proofing their properties.

He cited the use of attenuation ponds, artificial bodies of water built in subdivisions to make up for a loss of water-absorbing ground when new buildings go in.

"What happens is, as you go from trees or grasslands to hard surfaces such as roofs and roads, when you get a high heavy rainfall event the water runs off much faster," said Lee.

"So if you look at all the newer developments or even some of our older developments, now there are ponds or so that are at the lower end of the development these ponds, are designed to catch the water, hold the water back."