A winter flood warning was issued this week for the Otonabee River by Otonabee Conservation due to a combination of cold air temperatures, rough waters, high flows, heavy snowfall, and frazil ice formation in the area.
Frazil ice is not uncommon in winter—plunging air and water temperatures and calm, open water lead to the formation of needle-like ice crystals that can buildup and multiply. In the case of the Otonabee River, frazil ice accumulated along the shoreline, preventing water from flowing properly downstream.
Despite weather conditions earlier in the week that were conducive to more frazil ice formation, an update issued on Wednesday indicated that milder air temperatures and operations conducted by the Trent-Severn Waterway to decrease the flows from reservoirs on the river allowed flood waters to recede by about 20 cm in 24 hours. Flood water recession isn’t always linear, warns Otonabee Conservation, as water levels can hold or even begin to rise again.
On Friday, Otonabee Conservation downgraded the warning to a Flood Watch due to milder air temperatures and reduced water volumes. Residents are encouraged to remain cautious and to monitor conditions closely as the Trent-Severn Waterway slowly increases the flow of water on the river. When in doubt, keep SAFE: Staying Away From the Edge of all waterbodies in the area.
In the short term, residents and cottagers can minimize property damage from imminent flooding by taking electric appliances out of basements; placing valuables or furniture higher in the cottage or removing them completely; turning off any propane-, oil-, or gas-fired appliances and making sure their tanks are secure; turning the water off, but leaving the power on to ensure sump pumps can still function.
If you are in a high-risk area for flooding, you may want to consider more significant flood proofing.