Spring runoff appears to have peaked in northwestern Ontario, but flood risks remain

Even though northwestern Ontario is drying up after a wet start to spring, officials are still  watching the watersheds for potential flood risks. 

Lakehead Region Conservation Authority in Thunder Bay has downgraded its outlook from a flood watch to a conditions statement after area rivers and streams have reached their peak earlier this week. 

Still it's too early for people to let their guard down. 

"We still could see some future flooding. The snow surveys that we've done at the beginning of May are showing extremely above average snowpack still on the ground, especially in the rural area," explained Tammy Cook, chief administrator officer with the LRCA.

The snow surveys from this month are highest ever on record for the authority, Cook said, so even though rain isn't in the forecast for the next few days the snowpack melt will continue to contribute to high water levels. 

"So we typically measure between  two and eight centimeters. And this year at the beginning of May, we've measured between 26 and 76 centimeters of snow pack with really high water content," said Cook.

The water safety statement was issued for the lakehead region including the City of Thunder
Bay and municipalities of Neebing, Oliver Paipoonge, Shuniah and townships of Conmee, Gillies and Dorion.

Cook said the Neebing-McIntyre Floodway also continues to divert water from the Neebing River into the floodway channel, which is the first time diversion has occurred in the last five years.

"The floodway was put in to prevent flooding in the lower Neebing river in the intercity area. So we're seeing that diversion and it's been happening now for a few days. It's not unusual for it to divert in the spring. However, the unusual thing is we haven't seen kind of an eventful spring freshet for many years," said Cook.

Thunder Bay has escaped any major flooding this spring, despite a few serious spring storms that dumped snow and rain on the region in March and April. Fort Frances and Conmee Township have not been as lucky, with both communities reporting flooding and declaring states of emergency at the end of April. 

High water in Kenora 

Meanwhile, record rain and snow for the month of April has caused very high water flows to develop in watersheds in the Kenora area.

"April precipitation was the highest on record for the Lake of the Woods and Rainy-Namakan watersheds. The combination of rainfall, melting snow and frozen ground led to the rapid development of extremely high Rainy River flows," reads a release from the control board.

The Lake of the Woods Control Board (LWCB) said there's been an increased outflow from Lake of the Woods into the Winnipeg River in response to rising inflows.

But, the maximum outflow capacity is much less than the current rate of inflow rate to Lake of the Woods.

Lake of the Woods is expected to rise toward the top of the legislated operating range for the lake by mid-May, the control board said in an issued a release Wednesday.

"Wet weather could result in very high lake and river levels and preparations for this should be made in areas that have had impacts from past high-water events," reads the public information notice.

High flows are also expected to develop in the Lac Seul-English River watershed over the next week as the late melt of a "very deep" snowpack develops.

Lake of the Woods has risen by 65 cm since early April, while the Winnipeg River near Kenora has risen by 170 cm in the same period, according to the control board.

Most of the Winnipeg River level rise has occurred in the past two weeks as the LWCB directed a series of large outflow increases.