Most of the 250 to 300 people evacuated from their homes Saturday morning after an ice jam caused the Humber River to breach in Bolton, were expected to be allowed to return that evening.
However, 12 to 15 families may be out of their homes for months.
The trouble began late Friday night for the town's residents, after the estimated eight-foot jam caused the water to breach over and onto city roads.
The east side of Bolton along King City Sideroad - about a kilometre from downtown - is the hardest hit area.
Of the 85 homes impacted, at least 30 are believed to have suffered extensive damage.
A four storey apartment building was also evacuated early Saturday morning.
"The water is up to the side of the windows," NEWSTALK1010's Glenn Crouter said after driving through the area. "I'm looking at least five or six feet here where I am, where it's flooded, it's just incredible."
A temporary evacuation centre was set up Caledon Centre for Recreation and Wellness at 14111 Hwy 50 in Bolton. It's not known how long that will need to stay open.
"I'm kind of still in a little bit of a shock, like it's still not happening - kind of happening," evacuated resident Lilliana told NEWSTALK1010's Lucas Meyer, saying her and husband were able to come back to their home to quickly grab their things.
"We just packed some bags and [we'll] take it one day at a time, I guess. I don't even know."
Gregg McGibbon was also watching as the floodwaters moved in.
"All of the sudden the water started rising [and] coming up really fast," he said. "[It] came right up to our house and right now my whole backyard's underwater."
McGibbon said he and other residents had been concerned for weeks now about ice build up in the river, and it should never have occurred in the first place had the authority that manages flooding cleared it immediately.
But in a news conference, Caledon Mayor Allan Thompson refuted those complaints, saying the flooding did not happen in a 'problem area.'
"The ice jams - and the trees that are frozen with it - have come down the streams and have gotten jammed up here," he said. "If you looked here yesterday morning, nothing looked like it was going to be a problem."
"Since '87, we haven't had an incident, but again, we have no control over nature."
Early Saturday afternoon, fire officials said the water levels had lowered by about 20 centimetres, meaning the perimeter surrounding evacuated homes would be re-drawn later in the day. As a result, the town's fire chief confirmed that some residents may be able to return to their homes much sooner than others.
Work on removing the jam from the river was expected to continue overnight into Sunday, to ensure ice and debris heading downstream will not impact any other communities.
As of late Saturday afternoon, our media partner CTV News Toronto reported that the water levels had dropped to a point where all the roadways were dry.
- With files from Lucas Meyer, Claude Feig and Jackie Rosen