Steve Bagley, director of Chestermere's emergency management, says it's not yet clear how long the cleanup will take or how much it will cost.
Sunday's storm dropped as much as 200 millimetres of rain on the area in minutes, which caused the province to issue an overland flood alert.
The alert has since been lifted.
Operations at the Calgary airport were halted and about two dozen flights delayed or cancelled.
Power was also knocked out for a number of residents and traffic signals flashed red for several hours.
“We are continuing to assess the level of damage affecting upwards of 300 homes," Bagley said Monday of the Chestermere situation. "The city is working with its partners and assisting agencies in facilitating the cleanup process."
The MLA for Chestermere-Rockyview voiced her appreciation for the way neighbours pulled together after what she called “a waterfall of rain.”
"Every single person I talked to (Sunday) was in someone else’s basement helping them out,” said Leela Aheer of the Wildrose party.
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