Flood Watch North Bay District Tuesday, May 06, 2025

Flood Watch

North Bay District

Tuesday, May 06, 2025

 

11:30am

The Ministry of Natural Resources – North Bay District, is advising area residents that a Flood Watch is in effect for the Upper Ottawa River at the Town of Mattawa and Tomiko River watershed. Unless the bulletin is updated or extended, it will expire on May 13, 2025, at 4:00pm. 

Residents in the Upper Ottawa River/Mattawa area and Tomiko River watersheds should keep a close watch on conditions and exercise caution around lakes, rivers and streams. Water levels remain high in these areas because of recent rainfall events and high inflows from the northern watersheds.

Continued high water levels are expected to sustain flooding where it’s already occurring. Please alert and/or monitor any children and pets under your care to the possible dangers and supervise their activities around waterbodies.

Residents that have been affected by high water levels and flow conditions in the past should continue to take necessary action to protect and secure any vulnerable property in proximity to rivers, streams, creeks and lakes, and closely monitor developing conditions and regularly check for updated messaging.

The ministry is closely monitoring the weather and developing watershed conditions. Further updates will be issued as appropriate. 

TECHNICAL INFORMATION

Description of Weather System

The Upper Ottawa River at Mattawa and Tomiko River watershed areas are not forecast to receive significant precipitation over the next five days. Current forecasts show a maximum of 10mm falling during this period. If local thunderstorms develop today (May 6), there is potential for an additional 5-10mm of rainfall. Temperatures over the next five days are expected to remain seasonal. 

 

Description of Current Conditions

 

For the Upper Ottawa River at Mattawa, recent rainfall events combined with high inflows (snowmelt and rainfall) from the northern reservoirs is expected to keep water levels high over the coming days. The latest available Ottawa River level at Mattawa is 154.27m which is within the start of flooding level. Water levels have been within the start of flooding for a few weeks. At this time, the water level is not forecast to reach the start of damage level (154.80m).

 

Water levels within the Tomiko River watershed are currently high due to recent rainfall events and snowmelt in more northern areas of the watershed. Snowpack in the north has now melted or only remains in limited quantities. Water levels and flows have peaked and are starting to trend down. Levels are expected to keep trending down given the current five-day weather forecast.

 

Municipalities, residents and visitors, especially those in low-lying areas and along shorelines, are encouraged to monitor conditions and prepare accordingly. Shorelines and banks adjacent to waterbodies are very slippery and unstable at this time and when combined with cold, fast flowing water, pose a serious hazard.

 

DEFINITIONS

 

WATERSHED 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.

 

WATERSHED 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.

 

SHORELINE CONDITIONS STATEMENT – WATER SAFETY: indicates that along the Great Lakes shorelines high water, melting ice or other factors could be dangerous but flooding is not expected.

 

SHORELINE CONDITIONS STATEMENT – FLOOD OUTLOOK: gives early notice of the potential for flooding along the Great Lakes shorelines based on weather and lake conditions, and water safety information.

 

 

FLOOD WATCH: potential for flooding exists within specific watercourses and municipalities.

FLOOD WARNING: flooding is imminent or occurring within specific watercourses and municipalities.

LEARN MORE

Surface Water Monitoring Centre public webpage www.ontario.ca/page/surface-water-monitoring-centre

Environment Canada bulletins: www. weather.gc.ca

A close watch on local conditions and weather forecasts from Environment Canada is recommended.