FLOOD WATCH: Ottawa River – Arnprior to L’Orignal – Update #1

18-Apr-2019 18-Apr-2019

Weather Forecast: Forecasts indicate that two low pressure systems will be combining to produce significant rainfall of 50 to 65 mm and warmer temperatures over much of the Ottawa River basin beginning on Thursday, April 18 through to Saturday, April 20, 2019.

Environmental Conditions: The current snowpack throughout much of the Ottawa River basin remains at twice its normal depth for this time of the year and soils are saturated.

Risks: The Ottawa River Regulating Committee warns that levels and flows on the Ottawa River from Lac Coulonge down to the Montreal region are expected to rise extremely rapidly starting this Friday due to forecast rainfall and snowmelt runoff.

Forecasted precipitation and warmer temperatures will melt a large portion of the remaining snowpack in the central areas of the basin. Rainfall and snowmelt will combine to produce very high runoff, causing levels to rise sharply on the Ottawa River starting this Friday, April 19, 2019.

All flood-prone areas along the Ottawa River from Lac Coulonge down to the Montreal Archipelago are at risk.

Levels as high as those seen in May 2017, at the height of the flood, could be reached depending on the amount of precipitation received. An update will be provided on Saturday, April 20, 2019.

Due to the forecast uncertainty it is difficult to accurately predict how quickly water levels will rise and when river conditions may peak.

ACTION: Residents in flood-prone areas are encouraged to closely follow evolving conditions and to take necessary measures.

Residents are advised to stay away from watercourses where flows are high and where banks might be unstable. Parents are encouraged to explain these dangers to
their children.

Duration: This Flood Watch is in effect until Saturday, April 20, 2019.

South Nation Conservation (SNC) and its Ottawa partners, the Rideau Valley and Mississippi Valley Conservation Authorities, monitor the water levels and weather forecasts as part of the Flood Forecasting and Warning Program.

The Ottawa River Regulation Planning Board will be reassessing forecast conditions and providing hydrological condition updates on its website daily at

Please visit for more information. To provide feedback with respect to changes in water related conditions please email, posted on our Facebook (/SouthNationConservation) or Twitter (@SouthNationCA). For more information regarding the Ottawa River, visit

FOR MORE INFORMATION: Jason Symington, SNC Environmental Technologist,

FOR MEDIA INQUIRIES: John Mesman, SNC Team Lead of Communications,

FORWARDED TO: All Flood Forecasting and Warning Directory