Freshet 2020: “Nuisance flooding” possible amid rain and melting snow

Zandbergen photo, Nation Valley News file

CHESTERVILLE — The South Nation River appears swollen today, with a combination of above-freezing temperatures and rain prompting local watershed authority advice about the possibility of nuisance flooding over the next week.

Current conditions “may result in flooding in low-lying areas,” say South Nation Conservation and the Raisin Region Conservation Authority, remarking on the apparent start of the annual freshet — the early spring period in which local rivers break up and swell to accommodate melting snow.

Environment Canada has forecast a general freeze-thaw cycle for the next seven days as well as today’s potential 10 to 20 mm of rain. An additional 10 to 20 mm of rain is also possible at the end of this week, starting Thursday, March 12th.

Combined with the melting snowpack in the area, water levels are “above normal for this time of year,” according to SNC in the flood outlook statement in effect until next Tuesday, March 17.

“Ice cover in rivers and streams may breakup as a result of warm temperatures and higher flows, increasing the risk of ice jams and associated overbank flooding.”

Residents in flood-prone or low-lying areas, historically susceptible to flooding, should also take the necessary precautions to protect their property, such as:

• Ensuring sump pump is clear, in good working condition and has a backwater valve on it.
• Portable generator and backup pump.
• Ensuring downspouts are clear and the outlet is at least 3 m from the dwelling.
• Removing or securing items that might float away as flows increase.
• Removing valuable items from basements or lower floors that could be subject to flooding.
• Keep emergency phone numbers handy.
• Familiarize yourself with your municipality’s emergency preparedness plan.

To provide feedback to SNC with respect to changes in water-related conditions, email, visit their Facebook page (/SouthNationConservation) or Twitter (@SouthNationCA).

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