EMO keeping an eye on St. John River

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High snowfall. Rapid melt. Heavy rain. That’s the perfect recipe for disastrous ice jam flooding in the St. John River, but New Brunswick Emergency Measures Officials maintain that this year’s record snowfall does not guarantee the riverbanks will overflow.

The endless snowstorms that have pummeled Northwest New Brunswick and the rest of Eastern Canada have deposited record snowfalls, particularly in the north, and residents of flood-prone areas like Perth-Andover have been nervously wondering if the St. John River could overflow its banks. Disastrous floods in 1987 and 1993 caused millions in damages to Perth-Andover homes and businesses.

Environment Canada records indicate the northern half of New Brunswick had between 100 and 220 centimeters of snow on the ground on March 12, with the region enduring several major storms since then.

The water equivalent for the heavy snow pack is between 200 and 300 millimeters of water, which is 125 to 175 per cent above the normal values for the region. But all that water does not necessarily guarantee spring freshet flooding.

“We have record snowfall in the northwest and that means there is a lot of water that is suspended in the snow pack right now just waiting to melt out. If that melts out fast that will cause quite a gush of water to come into the river system. If we receive heavy rain on top of that then we could be looking at some flooding situations,” Andy Morton, NB EMO deputy director, stated. “It takes three things to happen to have flooding. It takes a lot of snow in the snow pack, two, you have to have rapid melt and three you have to have heavy rain.”

Morton said the New Brunswick EMO team stopped performing ice thickness measurement surveys in the Beechwood and Tobique head ponds, simply because the department could not draw any parallels with ice thickness and possible flooding. Instead the Emergency Measures Organization staff is keeping a close eye on river ice conditions.

“River Watch is monitoring conditions throughout the province, with a particular emphasis on the St. John River basin.... River ice conditions are also being monitored closely on the upper St. John, Aroostook, Tobique, Nashwaak, Kennebecasis, Canaan and Miramichi Rivers, where water levels are expected to rise. Ice break-up and movement may result in ice jams and localized flooding,” an EMO press release stated.

“We have folks that will patrol the river, typically from the roads, to look at the ice and see what is actually happening in terms of deterioration, break up, to see if any ice jams are occurring. They are our eyes on the ground,” Morton stated.

The deputy director said meteorologists are calling for below-normal temperatures until the middle of April, which would mean a moderate melt down.

“If we suddenly went from belowaverage temperatures to above-average temperatures we would get that rapid melt. If we get good maple sugar weather, warm days and cool nights, we would have a gradual melt off and shouldn’t have any difficulties.”

Morton encouraged residents who live beside rivers and streams to listen closely to weather forecasts and pay attention if heavy rain is predicted.

“If you live in a flood prone area, take some steps to protect your property. If your basement floods, move stuff out of harm’s way so you won’t suffer a loss.”

NB EMO officials urged residents top be ready to be “self-sufficient” for a minimum of 72-hours in the event of an emergency.

More tips and the ‘72-Hour Guide’ are available on the NB-EMO Public Alerts website at: http://www.gnb.ca/public.

A complete list of weather warnings is available from Environment Canada at: http://meteo.gc.ca/warnings/ nb_e.html.

A list of traffic advisories can be found on the Department of Transportation website at: http://www1.gnb.ca/cnb/transportation/indexe.asp.

River Watch is a partnership of the Department of Public Safety with federal, provincial and state agencies involved in monitoring and flow forecasting for the St. John River basin. Updates on forecasted river flows are available on the River Watch 2008 website at: http://www.gnb.ca/public/ Riverwatch/index-e.asp.