More rain and flood warnings issued Thursday in Hamilton come amid rising concern and repair costs from high water levels across the local watershed and around the Great Lakes.

The Hamilton region has already been reeling since major storms April 20 and in the first week of May that have brought Lake Ontario to its highest level in a century. 

And rain is expected to continue into Thursday afternoon in Hamilton, at times heavy. 

Environment Canada issued a weather statement that warned of potential pooling on roads and reduced visibility.

The national weather service said 10 to 20 mm already fell since Wednesday night, and another 20 to 30 mm is possible before the rain tapers off to showers Thursday afternoon.

Winds from the northeast are traveling 30 km/h with gusts up to 50 km/h during the day and into the evening, the forecast says.

Highest lake levels since 1918

The rain comes as Lake Ontario water levels are already significantly above normal after rains in April and May have led to the lake reaching the highest levels recorded at any time since 1918.

Both the Hamilton Conservation Authority and the Niagara Peninsula Conservation Authority warned Thursday that the forecasted winds could produce "storm surge and wave action" that could further flood and erode shorelines. People are urged to be cautious around the shoreline.

The HCA said Lake Ontario levels are expected to stay high for weeks and there may even be further increases because of rain throughout the Great Lakes Basin. 

City of Hamilton staff said there was some "minor over-road flooding" Thursday on King Street in Dundas due to the high lake levels. 

'Left us with quite a mess'

An influx of rain and runoff in recent weeks has volunteers and conservation workers hustling to check on all corners of the local watershed.

The Royal Botanical Garden's carp barrier was 12 inches underwater last week, after a few storms beginning April 20 began to overwhelm the 20-year-old guard against invasive species.

Workers there assembled a make-do fence with fencing and rocks. And the RBG has to put off their big 20th-anniversary party scheduled for May 29 because the trail to get to the fishway is underwater.

So far, that has been largely successful at keeping the invasive carp out, said the RBG's Tys Theysmeyer, head of natural lands, last week. 

Carp barrier

The Royal Botanical Garden’s carp barrier was 12 inches underwater last week, after a few storms beginning April 20 began to overwhelm the 20-year-old guard against invasive species. Workers there assembled a make-do fix with fencing and rocks. (Royal Botanical Garden)

But the flooded shorelines and erosion of escarpment ravines have still left crews at the RBG with a lot to do.

"The waterways took on a lot of garbage and sewers that overflowed because they just couldn't hold all the water," Theysmeyer said last week. "Left us with quite a mess."

At Cootes Paradise, volunteers brought their kayaks and rakes out last weekend to scoop up the plastic detritus swept into wetlands by the floods.

Even before this latest rain, the city has said it will have to spend as much as $5 million to undo the damage from flooding that resulted from heavy rain storms in late April and early May, said Dan McKinnon, general manager of public works.

  • Hundreds of metres of the Waterfront Trail are under water and large part of Confederation Park beach in east Hamilton have been washed away.
  • Sections of trails like the one east of the Wentworth Stairs have been closed as crews investigate erosion and collapse.
  • The city is spending at least $130,000 to pump water off roads near Beach Boulevard to minimize flooding impacts for nearby homeowners.
  • Access to the piers below the Burlington Lift Bridge has been fenced off due to "extremely high water levels and wind" that has submerged the concrete piers.

With files from Samantha Craggs