The Town of Rainy River has joined Fort Frances and Couchiching First Nation in declaring states of emergency because of high waters.
About 80 volunteers helped fill and place sand bags around several homes in Rainy River on Sunday, said Veldron Vogan, the town's chief administrative officer.
No evacuations have been necessary, but "everybody's got water in their basements," she said.
Waters rose so high near Fort Frances on Saturday that the McIrvine boat launch and dock were submerged, and parts of the government dock at the Point Park were swept down river.
"We fished them right out of the river and hauled them [pieces of the dock] up," said the town's emergency group information officer Patrick Briere.
"We had a loader with some forks and we had some slings attached to that and we pulled them right up onto shore, onto the road way."
A spokesperson for the Lake of the Woods Control Board said waters may not have reached their peak.
"They're closely watching things," Matt DeWolfe said. "Rainy River is at its highest level since 1950. Flows are tremendously high and Rainy Lake continues to rise."
Environment Canada issued a rainfall warning for the area, with predictions of up to 40 millimetres more rain on Sunday afternoon and more rain in the forecast overnight.
DeWolfe said there is also flooding in Lake of the Woods as the high waters move through the watershed and he said residents there should expect to see water rising even more quickly in the week ahead.
"The great uncertainty is how much more rain will we have," DeWolfe said.
The Lake of the Woods Control Board is holding an open house in Kenora on Tuesday to provide residents with more information.