Sarnia adjusts rules for the changing climate

Sarnia is trying to make sure homeowners aren’t facing flooding when more frequent and violent storms roll through the community.

It is changing its storm water management guidelines, forcing developers to install larger, more expensive sanitary sewers to deal with the increasing number of storms.

“It is an acknowledgement that climate change is real,” says Sarnia Mayor Mike Bradley.

“How do we continue to increase capacity…so the damage is less (during larger and more frequent storms).

“Doing this lessens the chance that someone in that new development has flooding.”

Bradley says this is only one step to improving the city infrastructure to deal with the more frequent and violent storms. The other is the ongoing effort to separate the sanitary sewers in the community. “We still have about 25 kilometers to separate.”

And he says it will be difficult to eliminate flooding completely. “If you could afford it, you could design for the 100 year storm, but you can’t afford it,” says Bradley. “We have to design the system to the averages and this is bumping up the averages.”

The new guidelines reflect a 10 percent increase in the average rainfall intensity over the next 40 years. Some municipalities are planning for as much as a 20 percent increase in rainfall intensity.

City Engineer Andre Morin says by following the new guidelines, he expects costs will increase about one percent which would be easily absorbed in the housing market. “This is mainly dealing with larger developments,” says Morin.

– Heather Wright