Update #3 – Flood Watch Maintained for Long Reach and Upper Watershed Lakes

(WCS – R07/2025)

April 4, 2025 – Water levels and flows across the Rideau Valley Watershed remain elevated following a recent significant precipitation event, with additional mixed precipitation in the forecast for the coming days. As a result, a Flood Watch remains in effect for the Rideau River from Smiths Falls to Manotick (Long Reach), as well as Bobs Lake and Christie Lake in the upper watershed. Reservoirs in the Upper Watershed have limited remaining capacity, increasing the risk of localized flooding in low-lying areas.

Residents are strongly encouraged to remain vigilant, monitor local conditions, and take necessary steps to protect their properties. Please refer to the recommended actions and safety measures provided below.

This Flood Watch is in effect until April 11, 2025 at 11:59 pm or until an update has been issued.

MORE DETAILS:

Weather Forecast: Environment and Climate Change Canada is forecasting moderate rainfall this weekend, with accumulations of 10-15 mm and additional mixed precipitation into next week. Daytime temperatures are expected to remain above freezing, with the possibility of a brief cool-down period by mid next week.

Environmental Conditions: Water levels and flows across the Rideau Valley watershed remain elevated following the recent significant precipitation. Reservoirs in the upper watershed now have limited capacity to absorb further snowmelt or rainfall. Over the past week, precipitation totals ranged from 60 to 84 mm, with the highest amounts observed in the Tay River and Upper Rideau subwatersheds. Water levels are expected to continue rising as additional melt and rainfall move through the system.

Risks: Portions of the Rideau River are under a flood watch, with localized areas under increased flood risk, based on the following factors:

• With limited capacity remaining within the upper reservoirs, increasing water levels may exceed full supply levels and result in flooding within low-lying areas.

Location-Specific Considerations: All water levels and flows across the Rideau Valley Watershed may increase with possible flooding in low-lying areas, including ditches, swales and stormwater features.

Rideau River - Smiths Falls to Manotick

With the ongoing melt and recent rainfall, water levels will continue to increase through the Long Reach of Rideau River (Smiths Falls to Manotick). With limited capacity remaining within the upstream reservoirs, further increases may contribute to flooding within low-lying areas.  

Residents in the City of Ottawa can check flood risks in their area using our Neighbourhood Flood Maps. If your property is within the RVCA watershed, use our Map your property tool to assess potential flooding impacts. Current water levels, flows and flood onset limits can also be reviewed on our Interactive Map.

Upper Watershed & Bobs Lake & Christie Lake

Water levels within the Upper Watershed, Bobs Lake and Christie Lake in particular, continue to rise due to the recent melt and rainfall. With the forecast rainfall, further increases are expected with possible flooding within low-lying areas. Parks Canada staff are closely monitoring conditions and adjusting operations as necessary to balance levels between the lakes. Residents in low-lying areas near Bobs and Christie Lake that are historically susceptible to flooding should take the necessary precautions to protection their property. 

Action & Safety Recommendations: Residents in flood-prone areas are advised to closely monitor water levels and flows and take the necessary precautions to protect their property, such as:

• Ensuring sump pumps are clear, in good working condition, and have a backwater valve.
• Keeping a portable backup generator and pump easily accessible.
• Ensuring downspouts are clear and directing water at least 3 m away from the dwelling.
• Securing items that might float away as flows increase.
• Removing valuable items from basements or lower floors that could be subject to flooding.
• Keeping emergency phone numbers handy.
• Familiarizing yourself with your municipality’s Emergency Preparedness Plan.

Residents are reminded that a Water Safety Statement is in effect until April 15th and advised to exercise caution when near rivers, streams, and other waterbodies due to the risks described above. Parents should inform their children of these dangers and provide appropriate supervision.

Duration: This Flood Watch is in effect until April 11, 2025 at 11:59 pm or until an update has been issued.

RVCA monitors water levels and weather forecasts as part of its Flood Forecasting and Warning Program. Updates will be provided as conditions change.

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 specific watercourses or municipalities.