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.

MAPPED ROAD CLOSURES, FLOODED AREAS AND SANDBAG LOCATIONS

VIEW WATER LEVELS IN SOUTH NATION WATERSHED

Current Watershed Conditions, Flood, and Drought Messages:

April 28, 2025

This FLOOD WATCH statement is an update to the Flood Watch Statement issued for areas along the Lower Ottawa River (Arnprior to Hawkesbury) on April 25th, 2025.

Water levels and flows have been gradually increasing along the main stem of the Ottawa River due to increased runoff from recent rainfall combined with snowmelt in the northern portions of the Ottawa River Basin. Levels and flows are expected to continue to increase over the next week due to additional forecasted rainfall.

From Pembroke to Britannia, minor flood levels have already been exceeded in some flood-prone areas, with the potential for major flood levels to be exceeded in some locations between Wednesday and Sunday.

From Gatineau (Hull Marina) to Hawkesbury, minor flood levels will likely be exceeded starting Thursday, with peak levels expected to remain below major flood levels.

The minor flood level is defined as the level at which parts of some streets, lawns and parks are beginning to flood, with no or few houses/buildings being affected.

The major flood level is defined as the level at which one or several streets are beginning to flood, with several houses/buildings or neighbourhoods being affected.

Water levels are currently expected to remain well below historical flood levels on the main stem of the Ottawa River.

This advisory includes flood-prone areas at Lake Coulonge, Chats Lake, Britannia / Lac Deschênes, Pointe-Gatineau, Cumberland, City of Clarence-Rockland, and other vulnerable areas down to Hawkesbury.

These results are dependent on the amount of rainfall received. Residents in flood-prone areas are encouraged to closely follow changing conditions by consulting the Ottawa River Regulation Planning Board Current Conditions page (https://ottawariver.ca/conditions/) and to take necessary measures.

Residents in flood prone or low-lying areas, historically susceptible to flooding, should take the necessary precautions to protect their property. Please ensure:

Sump pump is clear, in good working condition and has a backwater valve on it.
Easy access to portable backup generator and pump.
Downspouts are clear and the outlet is at least 3 m from the dwelling.
Driveway culverts are clear of debris and drain well.
Securing items that might float away as flows increase.

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 and provide appropriate supervision around all waterbodies.

The Mississippi Valley, Rideau Valley, and South Nation Conservation Authorities monitor water levels and weather forecasts with the Ministry of Natural Resources 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 www.ottawariver.ca/forecasts.

To view current flood warnings across Ontario, visit: www.ontario.ca/law-and-safety/flood-forecasting-and-warning-program.

This FLOOD WATCH STATEMENT is in effect until May 1^st, 2025 at 5:00 PM.

South Nation Conservation
Kat Watson, Coordinator, Early Warning Systems and Watershed Plans
kwatson@nation.on.ca,1-877-984-2948.

Definitions:

Water Conditions Statement: Water Safety: indicates that high flows, melting ice or other factors could be dangerous for such users as boaters, anglers, and swimmers but flooding is not expected.
Water Conditions Statement: Flood Outlook: gives early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high winds, or other conditions.
Flood Watch: potential for flooding exists within specific watercourses and municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.
Flood Warning: flooding is imminent or occurring within specific watercourses and municipalities.

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April 17, 2025

SNC advises that the Flood Outlook Statement of April 11th is being downgraded to a Water Safety Statement. Water levels and flows have declined throughout the week and remain stable.

Weather Forecast: Environment Canada is forecasting approximately 25 mm of rainfall over the next week, with 10 mm forecasted for Saturday and an additional 15 mm forecasted for Monday. Above zero temperatures are forecasted for most of the week with daytime temperatures ranging between 0 and 20 degrees Celsius.

Environmental Conditions: Water levels and flows in rivers and streams across the jurisdiction have declined and remain in stable condition. Forecasted rainfall may result in increased water levels and flows due to saturated soil conditions.

Risks: There is little risk of flooding, however, caution is still advised near all watercourses due to fast flowing water and slippery banks. Minor flooding may still occur in localized areas prone to poor drainage or those regularly impacted during spring runoff.

ACTION: Residents are advised to exercise extreme caution when near rivers and waterbodies due to elevated flows and slippery conditions. Parents are encouraged to explain these dangers to their children.

Residents in flood prone or low-lying areas, historically susceptible to flooding, should take the necessary precautions to protect their property. Please ensure:

Sump pump is clear, in good working condition and has a backwater valve on it.
Easy access to portable backup generator and pump.
Downspouts are clear and the outlet is at least 3 m from the dwelling.
Driveway culverts are clear of debris and drain well.
Securing items that might float away as flows increase.

Duration: This Water Safety Statement is in effect until April 28th, 2025 at 5 PM or until an update has been issued.

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

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

FOR MORE INFORMATION: Kat Watson, Coordinator, Early Warning Systems and Watershed Plans; kwatson@nation.on.ca, 1-877-984-2948.

Forwarded to: All Flood Forecasting and Warning Directory

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