Firefighters and volunteers have been sandbagging residences since 7 a.m. ET in the city, 175 kilometres east of Toronto, amid severe flooding along the Moira River.
Flood warnings are also in effect for the area's Salmon, Napanee and Trent Rivers.
“It all depends on the rain and our watershed this evening,” Belleville Mayor Neil Ellis told CBC News, noting the weather forecast has been “all over the map” — calling for between 10 and 40mm of rain.
“If there’s no rain in the northern part of our watershed we might make it through,” Ellis said.
In the meantime, he said, the city is looking for volunteers — anyone with “rubber boots and strong arms” — to help with sandbagging.
Similar to 2008
The water levels are nearing those of the flood that hit Belleville in 2008; said at the time to be the sort that occurs only once every ten years.
Ellis, who was also mayor at the time, said the city learned much from 2008, though the latest flood is posing its own challenges.
"The whole community has been out [volunteering] but everyone's getting tired," he said.
The city's fire chief on Friday warned residents not to be lulled into a "false sense of security" by the pleasant weather.
"Our message to residents is we really need to be prepared — it is coming,” Mark MacDonald said in a statement.