Port Bruce's collapsed bridge has become its latest tourist attraction
The collapse is still under investigation, but a Western University prof says 'scour' could be to blame
It's quite a sight to behold.
The dump truck that plunged into Catfish Creek Friday when the Imperial Road bridge collapsed remains perched in the water at a 45-degree angle, drawing a steady stream of onlookers from around Elgin County.
"If we charged five dollars a person for everyone that came down, we'd be able to replace the bridge," said Malahide County mayor and Elgin County councillor Dave Mennill.
The collapsed bridge will remain as-is for the time being, he said. The county has hired an engineering firm to investigate the collapse, and their investigation has to be completed before they can start moving pieces around.
This could take a bit of time, because the creek water is still so murky that it's hard for the engineers to examine the area beneath the bridge.
"[We're] going to have to wait until the water recedes before they do an assessment below," said Mennill.
The county also has to source equipment powerful enough to yank the truck out of the creek where it sits right now, he said.
How could this happen?
Ontario is the only province in Canada that requires bridges to be inspected every two years, according to the Ministry of Transportation.
The Imperial Road bridge was last inspected in 2016, and Mennill said it passed "with flying colours."
Although the final assessment of the bridge collapse is still to come, Mennill said he suspects the collapse was caused by the extraordinary levels of water and ice from last week's flood, something the engineers of 2016 might not have been able to predict.
"It's too much of a coincidence that we had the highest flow levels ever a week ago, and all of the sudden the bridge collapsed."
'Scour' could be to blame
Michael Bartlett, a professor of civil engineering at Western University, agrees.
Based on photos of the scene, Bartlett diagnosed the bridge with possible "scour," a problem where fast-moving water digs a hole around the base of a bridge abutment and destabilizes the whole structure.
During the flood, the weight or the momentum of the dump truck going over a bridge already suffering from scour could have caused the final collapse.
This might have been easily missed during the bridge's past inspection, said Bartlett.
"Those inspections tend to focus on the superstructure of the bridge," he said.
"It's less common to do detailed inspection of the sort of geotechnical conditions around the bridge unless there's particular evidence of a potential concern."
If the idea of scour—an invisible, underwater structural integrity problem—is making you sweat, the good news is that Bartlett said it's unlikely that what happened in Port Bruce will be seen in other areas of the province.
"Certainly the risk is a little higher right now than it was a week ago before the flood took place," said Bartlett.
"But I think appropriate measures are being implemented to try to inspect and monitor and make sure that things are okay."
Temporary bridge coming soon
A trip into town that used to take five minutes now takes twenty.
But problems could crop up for emergency services trying to get across the creek.
As of right now, the south side of the village is dependent on the Port Stanley fire department, said Mennill.
Within the next few weeks, the county is hoping to put a temporary Bailey bridge in place that can support the weight of a fire truck.
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