Watershed Conditions Statement – Flood Outlook

Message Number: 2026-01

Issued: January 8, 2026, at 3:00 PM EST

From: NBMCA Duty Officer, Angela Mills

Watershed Conditions Statement – Water Safety indicates that high flows, unsafe banks, melting ice or other factors could be dangerous for users such as anglers, boaters, swimmers, children or pets. Flooding is not expected.

If you have a flood emergency, please contact your municipality. If you live in an unincorporated township, please contact the Ministry of Natural Resources and Forestry (MNRF) – North Bay District.

A Watershed Conditions Statement – Water Safety is in place for the North Bay-Mattawa watershed.

Current Conditions:

Water levels on area lakes and rivers are generally at or slightly below normal for this time of year. Moisture content in the snowpack is an average of 60.3 mm (as of Jan 2), which is above normal for this time of year. There is also an ice lens in the snowpack from the late December melt and rains that will limit the snowpack’s ability to store rainfall.

Current water levels can be viewed by searching Station Names “Ottawa River”, “Mattawa River”, “Chippewa Creek”, “La Vase River”, “Wasi River”, and “Lake Nipissing” at https://wateroffice.ec.gc.ca/search/real_time_e.html

Forecasted Conditions:

Environment Canada has issued a Special Weather Statement for the North Bay – Powassan – Mattawa area, forecasting 15-25 mm of rainfall is possible tonight (Jan 8) through tomorrow, transitioning to snow on Friday. Temperatures are forecast to be well above freezing today, remain above freezing overnight, and reach a high near +8 ºC Friday (Jan 9). Temperatures will return to below freezing Friday night and precipitation will transition back to snow. Mild temperatures, especially overnight, combined with rainfall will trigger melt from the snowpack.

Water levels on the Ottawa River are managed by upstream dams and reservoirs operated by provincial and federal governments. The water level of the Ottawa River at Mattawa is expected to remain stable, per the Ottawa River Regulating Committee. Forecasts are available at https://ottawariver.ca/

The water level on Lake Nipissing is regulated by dams operated by the federal government. The water level of Lake Nipissing is expected to continue to slowly decrease. The changes to water levels on Lake Nipissing depend on the amount of water flowing in from rivers, precipitation, and the amount of water flowing out through the control dams to the downstream French River. Forecasts are available at https://www.canada.ca/en/public-services-procurement/services/infrastructure-buildings/bridges-docks-dams/frenchriver-dam.html

Historic Flood Conditions:

For comparison, in response to 34.5 mm of steady rain over 12 hours with frozen or saturated soil conditions and minimal remaining snowpack in March 2024, the water level on Chippewa Creek increased by 83 cm over 15 hours, peaking about 3 hours after rain ended.

Risk:

Forecasted warm temperatures and rain will trigger snow melt and increase hazardous conditions around lakes, rivers, and streams. Rain on frozen conditions may result in rapid changes in water levels on urban creeks in the City of North Bay, especially during and after periods of intense precipitation. Water levels in the watershed will increase and localized flooding is possible in low-lying areas. Increased flows may impact shoreline ice stability. Widespread flooding is not expected at this time.

All residents, especially those in low lying areas, are encouraged to monitor the conditions that are developing. Banks adjacent to rivers and creeks are very slippery at this time and when combined with cold open water, pose a serious hazard. The public is encouraged to keep children and pets away from watercourses and off waterbodies.

Municipalities are encouraged to monitor water crossings for debris that may affect the movement of water through culverts and bridges. A close watch on local conditions and updated forecasts and warnings from Environment Canada is also recommended.

Staff at the North Bay-Mattawa Conservation Authority will continue to monitor weather and watershed conditions and update this message based on the changing weather and streamflow conditions.

This message will be in effect until (or updated before) Monday, January 12, 2026 at 4:00 PM EST.

The general public is advised of these messages through the www.nbmca.ca website with the flood status icon and a link to information about current conditions. NBMCA also circulates these messages to local media and social media, posting on Twitter (@theNBMCA), Instagram (nbmcainfo), and Facebook (NBMCA).

The public is invited to share photos of watershed conditions on social media using #NBMCAFlood. Media Release

North Bay-Mattawa Conservation Authority Subwatershed map — *^{NBMCA Subwatershed Map}*

Lake Nipissing

Flows through the dams are based on daily analysis of the current status of the lake and river and as agreed to by the Sturgeon-Nipissing-French-Wanapitei Water Management Group. Weather forecast is considered, along with the inflows from the upper watersheds and outflows through the dam to the French River.

You can view the current level on Lake Nipissing at North Bay on the graph below and the French River at the Water Survey of Canada (WSC) website. Fluctuations in the levels are a result of the strong winds affecting the movement of surface water. Water level and flow information for the South River and Sturgeon River systems is available from Ontario Power Generation (OPG).

Flood warnings for Ontario can be found on the Ontario Flood Forecasting and Warning website.

Why the fluctuation in water level readings on Lake Nipissing? Lake Nipissing can sometimes act like a bathtub, with water shifting in the lake, depending upon wind direction, speed and atmospheric pressure - known as a wind surge or seiche. At times the wind can have such an impact that it may result in the level being higher or lower at the French River gauge compared to the gauge located on the North Bay shoreline.

Mattawa River

The current Ottawa River water level may be viewed at the Water Survey of Canada (WSC) website (note that there is a delay of several hours, and 100m should be added to the gauge reading for metres above sea level).

The Ottawa River Regulation Committee and Ontario Power Generation which operates the Otto Holden Dam provide information online regarding the management of water levels on the Ottawa River. To view water levels and current conditions on the Ottawa River visit the Ottawa River Regulation Planning Board and Ontario Power Generation.

Watercourses and Monitoring throughout the Watershed

There are other watercourses within the NBMCA jurisdiction which are monitored by NBMCA and other agencies. These gauges are maintained by Water Survey Canada - Environment Canada and can be viewed in real-time online.

In addition to the Water Survey of Canada gauges, there are other staff gauges which are monitored by NBMCA or the Ministry of Natural Resources and Forestry: