Published on Apr. 30, 2026, 11:05 AM
2nd flood peak from Pembroke to Montreal remains ‘possible’ in coming weeks, planning board says
Water levels and flows along the main stem of the Ottawa River continue to rise slowly from Mattawa to Pembroke, while they are stable or slightly declining between Lake Coulonge and Carillon, according to the latest update from the Ottawa River Regulation Planning Board.
In Mattawa, water levels are expected to exceed the major flood level, the board’s Wednesday update added.
Snowmelt is increasing in the northern part of the basin, sending more spring runoff downstream.
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“The rainfall that began [Tuesday] is leading to increased runoff from the northern and central parts of the basin, with volumes depending on how much additional rain falls and where,” the board stated. “This is expected to lead to water levels and flows increasing gradually in all locations over the next few days.”
In the longer term, a second flood peak from Pembroke to Montreal remains “possible” in the coming weeks.
More rain on the way
Ottawa-Gatineau has remained under a moderate rainfall warning throughout Wednesday, with up 50 millimetres of rain expected in the evening.