Thursday’s near-record downpour has raised questions about Brandon’s drainage capacity, but the city’s top engineer said they could never have been prepared for such an extreme deluge.
"We would never get to the point where we would be designing for something that fast," said Patrick Pulak, the city’s director of engineering and water resources.
Westman was hammered with a month’s worth of rain in just a few hours Thursday evening and all that rain had to go somewhere.
And as it slowly drained from flooded streets and basements, it flowed into the Assiniboine River, which spiked nearly 10 inches at the end of the storm. River levels are measured hourly at the First Street bridge, and they show the river level moving up by about 25 centimetres as rain showers turned heavy around suppertime Thursday.
Sycamore Drive, one of the city’s flooding hot spots in Brandon’s west end, saw significant backup and water was lapping up to the edge of the homes in the new development.
Area resident Karen Mandryk said similar flooding has happened on the street every year since she moved in three years ago, and she thinks there aren’t enough drainage points on the subdivision’s main drag.
"Property damage is my biggest concern," she said. "One of us always has to go out and make sure the drain stays clear to give it as much drainage as possible, so we’re wading out there in hip-deep water ... It’s a sewer. What are we walking in?"
The area’s city councillor Stephen Montague (Richmond) also raised concerns about how much the city’s system can handle.
"I appreciate that the amount of rain that we did receive was quite extraordinary," he said. "In the newer developments, knowing there is more of a trend of bigger rainstorms, my opinion is that the infrastructure should be able to handle it."
While Montague and residents point to three years of wet springs that have brought a wash of flooding concerns, Pulak said that doesn’t make a trend.
"We can’t design a system that will handle everything," Pulak said. "The whole system was backed up."
Like anything else, the level of drainage the city can handle is largely stipulated by the city’s bean counters.
"Designing infrastructure is a balance between servicing and cost," Pulak said.
"We want to maintain a high level of service and get as much bang for our buck, but at the same time, the sky’s not the limit for this. People don’t want to see their taxes go through the roof."
Environment Canada recorded 75.2 mm of rain in 24 hours at the airport weather station, which is just under three inches.
That’s not quite a record for the airport station, which received 86.4 mm on May 6, 1964. But it’s close to a record for June. The most rainfall ever recorded in June at the airport was on June 2, 1953, when 80 mm fell.
In a normal June, Brandon receives 80.7 mm of rain in the entire month.
But climate change is making more rain the new normal. Twenty-five years ago, Brandon got just 66.9 mm of rain in a normal June.
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