Current Watershed Conditions


South Nation Conservation works with its partner municipalities along the South Nation, St. Lawrence and Ottawa Rivers to provide advanced notice of flooding and low water conditions through the provincial Flood Forecasting and Warning and Low Water Response programs.





Current Watershed Conditions and Flood Messages:


March 26. 2021 - Water Conditions Statement: Flood Outlook — Lower Ottawa River

A Flood Outlook Statement is being issued for areas along the Lower Ottawa River. Based on current snow cover and weather forecast, it is anticipated that levels and flows along the main stem of the river from Arnprior to Hawkesbury are expected to begin to rise over the next few days but will remain within the normal range of fluctuations associated with the spring freshet period.

Presently, the snow cover varies significantly across the 146,300 square kilometre Ottawa River basin, with some areas in the south of the basin having no snow cover at all. Where there is snow cover, the snow water content (amount of water contained in the snow) is lower than average over much of the basin except in the west-central portion of the basin where average conditions prevail. Snow water content is only one of several factors impacting the magnitude of the spring freshet each year.

The Ottawa River Regulating Committee indicates that with the current weather forecast, flooding in low-lying areas is not expected to occur over the next few days. Levels are currently expected to remain below flood thresholds. While it is not possible to completely rule out the occurrence of a large spring freshet, the factors that are known at this time, namely below average snow water content in all locations and an early spring start, are positive indicators of a year without excessive flooding along the Ottawa River.

Throughout the freshet period, the combination of heavy rainfall and snowmelt may result in rapid increases in water levels and flows on the main stem of the Ottawa River from Mattawa down to the Montreal Region.

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 dangers to children.

The Mississippi Valley, Rideau Valley, and South Nation Conservation Authorities monitor water levels and weather forecasts with the Ministry of Natural Resources and Forestry as part of the Flood Forecasting and Warning Program. Updates are provided as conditions change.

The Ottawa River Regulating Committee will be reassessing forecast conditions and providing hydrological condition updates on its website daily at

To view current flood warnings across Ontario, visit:

This FLOOD OUTLOOK STATEMENT is in effect until April 16, 2021 at 5:00 PM.



Weather Forecast:
Environment Canada forecasts rainfall amounts ranging from 20 to 30 mm this week until Friday, March 26. Daytime temperatures are expected to be above freezing this week and next week. Overnight temperatures will drop below freezing on March 28, which will cause the freeze-thaw cycle to resume.

Environmental Conditions:
A substantial amount of the snowpack throughout the watershed has melted due to the warming weather. Water levels are above normal but within average ranges for this time of year. Levels have peaked and have been slowly declining.

Based on this week's weather forecast calling for rain, the remaining snowpack is expected to melt and cause water levels to rise again across the watershed.

Ice cover in rivers and streams may break up due to warm temperatures and higher flows, increasing the risk of ice jams and associated overbank flooding.

Higher than normal water levels may also cause nuisance flooding in low-lying areas.

Residents are advised to stay away from rivers as the weather forecast may rapidly increase river flows, and banks might be unstable and slippery. Parents are encouraged to explain these dangers to their children.

Residents in flood prone or low-lying areas historically susceptible to flooding should also take the necessary precautions to protect their property, such as:

  • Ensuring sump pump is clear, in good working condition and has a backwater valve on it.
  • Having a portable generator and backup pump available.
  • Ensuring downspouts are clear and the outlet is at least 3 m from the dwelling.
  • Removing or securing items that might float away as flows increase.
  • Removing valuable items from basements or lower floors that could be subject to flooding.
  • Keep emergency phone numbers handy.
  • Familiarize yourself with your municipality's emergency preparedness plan.

This statement is in effect until Wednesday, April 7, 2021.

SNC monitors water levels and weather forecasts as part of the Flood Forecasting and Warning Program. Updates are provided as conditions change.

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

FOR MORE INFORMATION: Omar Kana'n, Water Resources Specialist – Engineering, 1-877-984-2948,

Forwarded to:  All Flood Forecasting and Warning Directory





South Nation Watershed St. Lawrence River Ottawa River

March 9, 2021: Flood Outlook

March 24, 2021: Flood Outlook (Update)

None at this time.

March 26, 2021: Flood Outlook


Past Statements:


Water Conservation and Well Management Fact Sheets: