Forecast for 2023-05-05

River conditions forecasts posted on 2023-05-05 by Ottawa River Regulating Committee

Between 45 and 90 mm of precipitation fell over the basin from Saturday April 29 to Wednesday May 3 causing flows and levels to increase rapidly on the main stem of the Ottawa River. Levels and flows have peaked from Mattawa to Lake Coulonge and are slowly reaching a peak elsewhere today. Water levels have already started a slow decline in Mattawa and Pembroke. Elsewhere, they are expected to stabilize over the weekend and should begin to decline slowly next week with the return of sunny and drier weather. Please refer to the forecast section of our website for more information about the expected rate of level decline. Reservoirs in the northern part of the watershed, which are being used to store runoff and minimize flooding downstream, are rapidly filling. Once reservoirs are full, they will have little capacity to reduce river flows in downstream areas should additional weather systems occur. Levels will therefore remain susceptible to further rise should additional significant rainfall occur over the coming few weeks.