Rising waters in region heighten flood warnings
Officials keeping an eye on ice jam in Cambridge
WATERLOO REGION — Record temperatures, melting snow, ice jams and well more than a month’s worth of rain are conspiring to push the Grand River and its tributaries past their banks.
Flood warnings are in place throughout the entire watershed as water levels creep higher, submerging low-lying areas and prompting widespread road closures. And it’s not even spring yet.
“An event of this magnitude is unusual for February,” noted Grand River Conservation Authority communications coordinator Cam Linwood.
Key areas of concern in Waterloo Region include the communities of New Hamburg and Ayr, and in Cambridge where the largest ice jam that GRCA officials have seen in decades along that stretch of the Grand is sitting like a cork in a bottle.
And while that jam — stretching about two kilometres from Fountain Street to the Parkhill Dam area, and made up of huge chunks of ice as thick as two feet in places — is showing some signs of erosion, no one knows when it will give up and release for good.
The longer it takes, the greater the volume of water building up behind it, threatening parts of Blair Road and possibly backing up along the Speed River through Preston, as well.
“It’s the first time we’ve seen an ice jam this significant in that stretch of the river for 40 years,” said Linwood. “As the upstream flows begin to increase water levels in Cambridge, that continues to put more and more water into that ice jam.”
When the ice jam does let go, the chunks will break up as they flow over the Parkhill Dam. Linwood said there’s no threat to the dam itself.
In New Hamburg and Ayr, where some degree of flooding is a common sign of spring, residents were bracing for Level 3 flood conditions that haven’t been seen in several years.
“They will see some flooding in the towns themselves. Roads that they haven’t seen flood in the past few years, they may see flood,” Linwood said. Fortunately, these two communities tend to be well-prepared for flooding, he said.
Flows were expected to peak overnight Tuesday in New Hamburg, and overnight Wednesday in Ayr. Other areas in the region that could experience flooding include West Montrose and areas downstream of the New Dundee dam.
“This event for southern Ontario will certainly be a noteworthy one,” said Environment Canada’s Geoff Coulson.
By noon Tuesday, Waterloo Region had already received about 32 millimetres of rain since it began falling on Monday, and an additional 20 to 25 mm was forecast into Wednesday. In a typical February, the area picks up about 30 mm of rain for the entire month.
A temperature record of 10.8 C for Feb. 20 had already been broken by 11 a.m. as the mercury climbed toward a forecast high of 14 C.
With the snowpack melting and rain falling onto sodden or frozen ground, conditions were ripe for flooding to occur, especially with ice jams locked in place in communities, including Cambridge, Brantford and Cayuga.
Temperatures are set to fall back to more seasonal conditions on Thursday and Friday, with a rain-snow mix possible on Friday and again over the weekend.
“It is almost turning into the tale of two Februarys,” Coulson said, with a very cold first half giving way to a milder second act.
If temperatures had remained chilly, these waves of rain could instead have resulted in “serious amounts of snow through a multiple-day event,” Coulson said.
But for now, communities from Grand Valley down to the Lake Erie shoreline are dealing with too much water. A Canadian Coast Guard icebreaker is at work at the mouth of the Grand River in Port Maitland to reduce the potential for ice jams; similar operations have occurred there in past years.
While the GRCA is able to capture a lot of excess water in its storage reservoirs, officials will have to determine what to do with it once the flood threat subsides, Linwood said. They’ll look at historical trends and forecast models in deciding how much water to release. The reservoirs need to be at sufficient levels in the coming months to augment low summer flows.
People are urged to stay well back from slippery banks and swollen rivers and streams, and off of ice that’s likely unsafe. Keep a close eye on children and pets, and don’t drive on closed roads.
More information is available on the authority’s website at grandriver.ca.