BERWICK, Ontario - South Nation Conservation Authority this week advised that warmer temperatures and forecasted rain will mark the beginning of the spring freshet which will result in quickly rising river water levels and unsafe conditions.
Environment Canada is forecasting sustained above-zero temperatures starting March 6. Daytime temperatures are expected to reach up to 15C in some areas leading to snowmelt. Warmer temperatures will likely be accompanied by rainfall, with total rainfall amounts approaching up to 25 mm by March 7. The extended forecast shows a continued warming period with the potential for an additional 50 to 80 mm from March 10 to 13.
Snowpack and snow water equivalent across the South Nation Conservation jurisdiction are slightly above normal for this time of year, while ice thickness on rivers across the jurisdiction are mostly below normal. River water levels are currently on the low side of the normal seasonal range, creating capacity in local river systems.
It is anticipated that by March 7 snowmelt and rainfall will result in increased river water levels and fast flowing water. Considering the forecast, the SNC flood forecast model predicts that water levels will peak on March 13, resulting in flooding of low-lying areas, floodplains, and areas with poor drainage. Widespread flooding is not anticipated at this time; however, this can quickly change depending on the amount and intensity of rainfall received.
Rivers across the jurisdiction will see higher water levels, fast flowing water and slippery or unstable banks. Additionally, these conditions elevate the risk for ice breakup and ice jams at bridges, culverts and other areas producing localized flooding concerns in low lying areas.
Residents are advised to exercise extreme caution when near rivers and waterbodies due to increasing river flows and slippery conditions. Any ice-covered bodies of water are considered unsafe. Parents are encouraged to explain these dangers to their children.
The timing and amount of rainfall received will determine the extent of flooding. Residents in flood prone or low-lying areas, historically susceptible to flooding, should take the necessary precautions to protect their property.
Please ensure:
Sump pump is clear, in good working condition and has a backwater valve on it.
Easy access to portable backup generator and pump.
Downspouts are clear and the outlet is at least 3 m from the dwelling.
Driveway culverts are clear of debris and drain well.
Securing items that might float away as flows increase.
This flood outlook statement is in effect until March 9 at 5 p.m. or until an update has been issued.
SNC monitors the water levels and weather forecasts as part of the Flood Forecasting and Warning Program. Updates are provided as conditions change.