May 1, 2019 — Rideau Valley Conservation Authority (RVCA), in conjunction with the Mississippi Valley Conservation Authority (MVCA) and South Nation Conservation (SNC) is maintaining the FLOOD WARNING issued on April 19, 2019 for the areas under our jurisdiction along the Ottawa River.

The most recent model outputs from the Ottawa River Regulation Committee (ORRC) indicate that water levels have peaked on Lac Coulonge.  From Chats Lake down to Hawkesbury/Grenville, levels have stabilized but are expected to increase due to forecasted rain of 15 to 35 mm on a large part of the basin starting today.

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

Peak water levels across many areas of the Ottawa River will exceed those experienced in May 2017 over the next couple of days. Levels will remain high and are forecasted to peak between Thursday and Friday. Risk is highly dependent on the amount of precipitation received.

MVCA areas of concern: 

Water levels in the Constance Bay area have exceeded those levels reached in May 2017. The ORRC currently forecasts water levels to rise an additional 0.30 m to 0.50 m above the 2017 levels. Updates to this projection will be provided as they become available.

RVCA areas of concern:

Water levels in the Britannia area (Grandview Road, Britannia Village, and the Belltown Community) have exceeded those levels reached in May 2017. The ORRC currently forecasts water levels to rise an additional 0.30 m to 0.50 m above the 2017 levels. Updates to this projection will be provided as they become available.

Water levels east of Cumberland Village (Boise Village, Morin Road, Leo Lane) are equal to those levels reached in May 2017. The ORRC currently forecasts water levels to rise an additional 0.20 m to 0.40 m above the 2017 levels. Updates to this projection will be provided as they become available.

SNC areas of concern:

Water levels in Clarence-Rockland and Alfred-Plantagenet have risen 0.03 m over the last 48 hours. Levels are forecasted to rise an additional 0.2 m and peak tomorrow, Thursday, May 2. Water levels are expected to be 0.2 m higher than the May 2017 flood.

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

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.

This FLOOD WARNING is in effect until Saturday, May 4, 2019.

RVCA and its Ottawa partners, MVCA and SNC monitor the 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 Regulation Planning Board will be reassessing forecast conditions and providing hydrological condition updates on its website daily at www.ottawariver.ca/forecast.php.

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

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"Rideau Valley Conservation Authority is a partnership of municipalities within the Rideau Valley watershed created under the Conservation Authorities Act to deliver a range of programs in watershed management and natural resource conservation."

RVCA Watershed Conditions Statements:

• Water Safety – High flows, unstable banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.
• Flood Outlook – Early notice of the potential for flooding based on weather forecasts, calling for heavy rain, snow melt, high winds or other conditions that could lead to high runoff, cause ice jams and/or lakeshore flooding or erosion.
• Flood Watch – Flooding is possible in specific watercourses or municipalities. Municipalities, emergency services and individuals in flood-prone areas should prepare.
• Flood Warning – Flooding is imminent or already occurring in area watercourses.