FLOOD WARNING – Lake Talon & Mattawa River Subwatersheds, and North Bay Urban Creeks
FLOOD WATCH – Other Areas
(North Bay April 18, 2023). A Flood Warning is now in effect for the Lake Talon and Mattawa River subwatersheds according to the North Bay-Mattawa Conservation Authority (NBMCA). The Flood Warning continues for creeks within the City of North Bay urban areas. A Flood Watch remains in effect for all other areas of the North Bay-Mattawa watershed. The potential for localized flooding exists, especially in low lying areas, as the snowmelt progresses, and rainfall occurs.
“Very warm temperatures over the past week triggered significant snowmelt that continues to affect local watercourses,” said Angela Mills, NBMCA Duty Officer. “Water levels in Lake Talon and watercourses in the Mattawa River watershed have risen in the last few days. Urban creeks in the City of North Bay remain high and in some parts are near top of bank.” Watercourses in rural areas may also experience high water levels. Note that water levels on Lake Nipissing are near normal and shoreline flooding is not expected at this time.
The Ministry of Natural Resources and Forestry operates several dams within the Mattawa River watershed. The outlet of Lake Talon is one of those dams and is currently above maximum water levels. Lake Talon water level increased by 115 cm since April 10. Flows are expected to increase downstream of Lake Talon on the Mattawa River. Other watercourses and lakes in the Mattawa River watershed, including Boom Creek, Amable du Fond River, Chant Plein Lake and Smith Lake are very high. Mattawa River water level at Hurdman Dam is 67 cm higher than it was on April 10.
Note that the Ottawa River water levels are managed by upstream dams and reservoirs operated by provincial and federal governments. The Ottawa River water level at Mattawa has started to increase.
Chippewa Creek water level has increased overall by 51 cm since April 10. The water level on the La Vase River increased overall by 43 cm since April 10. High water on the La Vase River has closed the trails in the Corbeil Conservation Area in the Municipality of East Ferris. The water level on Wasi River increased overall by 36 cm since April 10.
Rain is forecasted on Thursday through Saturday (April 22) with 20 to 40 mm expected to fall on already saturated ground. The rainfall may contribute to, or maintain, the existing high water levels on area watercourses and lakes. Temperatures will be around normal to slightly cool for this time of year, with daytime highs between 3 and 10 ºC, and overnight lows expected to be near 0 ºC.
The snowpack water content on April 14, 2023, measured an average of 81 mm water storage in the North Bay-Mattawa watershed, which was a substantial decrease from an average of 201 mm of water equivalent on April 6. This is due to the significant snowmelt that has occurred in the past few days.
For comparison, when river-based flooding occurred in April 2019, the snowpack water content was 123 mm (measured April 15, 2019). Rainfall of 31.8 mm was measured April 18, 2019. Daytime and overnight temperatures were above freezing.
“Residents, especially those in low lying areas, are encouraged to monitor the conditions as they develop, and prepare accordingly. Shorelines of creeks and rivers will be 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,” said Chitra Gowda, NBMCA CAO.
As part of the NBMCA Flood Forecasting and Warning Program, staff will continue to monitor weather and watershed conditions and update this message based on the changing weather/streamflow conditions. Staff remain in contact with municipalities and other partners as required.
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), Facebook (@theNBMCA) and Instagram (nbmcainfo).
This message will be in effect until (or updated before) Monday, April 24, 2023 at 4:00 pm.
Angela Mills, Duty Officer, cell: 705-497-4668
Chitra Gowda, CAO, cell: 705-477-0372