GRCA warns of 'major flooding' as crest moves downstream

Flooding shuts down parts of New Hamburg From CTV Kitchener’s Heather Senoran: Roads looked like rivers as the Nith River overflowed into New Hamburg’s streets.

Water levels have peaked across the upper Grand watershed – but lower reaches of the watershed are being warned to brace for higher water and likely flooding.

The GRCA issued its latest forecast early Wednesday afternoon, warning of “major flooding” in the southern portion of the watershed.

According to GRCA data, the upper reaches of the Grand peaked late Tuesday night. Water levels in West Montrose peaked at 250 cubic metres per second – enough to flood the village before levels started receding early Wednesday morning.

Flows in Kitchener peaked above 500 km/h cubic metres per second early Wednesday morning, while the Galt part of Cambridge saw flows of 900 cubic metres per second at 1 a.m. Wednesday. That fast-moving water swept a large amount of ice onto Highway 24 south of Ainslie Street, forcing a closure of the highway that continued into the afternoon.

Downstream in Brantford, a state of emergency was declared and several neighbourhoods were evacuated after the Grand hit 3,000 cubic metres per second around 8:30 a.m. Wednesday. The river level continued to fluctuate up and down for the rest of the morning. The GRCA said levels in Brantford had stabilized and would slowly decrease into Thursday.

The surge of water that had flooded Brantford was making its way downstream by early Wednesday afternoon, as flows in York passed 1,000 cubic metres per second.

The GRCA warned Wednesday afternoon that water levels would soon start to increase in Caledonia. If ice jams from Brantford broke up, a significant amount of water could make its way down the river in a short period of time.

Also being watched closely was the situation in Cayuga, where an ice jam was in place.

Ice at the mouth of the river was broken up with the assistance of the Canadian Coast Guard, reducing the risk to communities like Port Maitland and Dunnville. Flooding was still possible in these communities, the GRCA warned, depending on the behaviour of water and ice upstream.

Authorities were also concerned about the potential for flooding from the Nith River, which peaked in New Hamburg early Wednesday morning at 400 cubic metres per second. Water levels in Ayr continued to increase Wednesday morning and were expected to peak Wednesday night.

The Conestogo River peaked Tuesday night, reaching flows of 300 cubic metres per second in Drayton and 160 cubic metres per second downstream in St. Jacobs.

Flows in the Speed River were expected to increase on Wednesday due to water being discharged from the Guelph dam.