As mentioned in a post on Facebook by our city councillor Jeff Leiper, sewer overload warnings have been delivered to the appropriate houses (a flyer or fire department visit); if you didn’t get one then there’s no worry about keeping usage down.
The Pontiac and Keyworth sandbag wall should be okay; the water won’t be rising too much and should mostly affect low driveways there.
Also the Patricia sewer overflow seems to be mostly ground water coming from upstream (higher water pressure). I assume it’s better to let it flow out there than filling the pipes.
