Flooding risk rises as rain, melting snow, and the return of cold weather collide

The risk of flooding is rising as heavy rainfall, rapid snowmelt and a sudden freeze inundate waterways across the region. CTV’s Sean Irvine explains.

Flood warnings and watches are in place across the region as heavy rains and snowmelt have combined to overwhelm waterways - and more water is coming.

In London, flood control doors at Fanshawe Dam were opened slightly on Wednesday as water levels on Fanshawe Lake rose significantly.

Over the past few days, the lake has risen almost seven metres or 22 feet.

CTV News requested an interview with Senior Water Resources Manager Mark Helsten to discuss the emerging situation, but he declined.

However, Emily Chandler, a communications and marketing specialist with the Upper Thames Valley Conservation Authority (UTRCA) confirms plenty of water is still being held back.

“With the operation of this dam, we have actually been able to prevent or reduce the flow going into London by 45 per cent,” she said.

The UTRCA and a long list of other watersheds to the north of the city have issued alerts. They range from flood advisories to watches and warnings.

The situation is difficult enough in some places that roads and highways have been washed out, including a section of Highway 21 from just north of Goderich to Amberley.

“It’s the amount of rain that came down within a short period of time, combined with that snowmelt. So, the ground was already saturated. And when you have that, you just have the water run off much quicker, and you have that flooding,” said Chander.

The runoff will be sped up by a sudden return of cold temperatures, helping to keep the ground frozen.

Another concern is the speed of waterways. In many areas, rivers are raging.

It is the reason why Chris Reed is keeping a close hold of his dog Molly in downtown London.

“I keep her short on the leash here so she can’t get too far away from me,” he told CTV News.

While the water must go somewhere, a lot of debris on the Thames River is now collected above Fanshawe Dam before it heads downstream, thanks to a newly installed barrier.

“What will happen is some of it will submerge, some of it will just go down the shoreline, but most of it won’t fall over the dam,” said Chandler.