Thursday’s sudden downpour cut a swath through Winnipeg from the southwest corner diagonally to the northeast part of the city, according to Environment Canada.
Officials at the national weather service say unofficial rainfall collections taken around the city show that the heaviest amount of rain fell in the Whyte Ridge area, where a reading of 102 millimetres was reported. Other areas of note include Linden Woods (73 mm) and River Heights/Tuxedo area (65 mm).
Environment Canada says readings in the southwest corner typically ranged between 50-82 mm over the duration of the storm, which lasted approximately two-and-a-half hours (through varying degrees of intensity).
City officials said 83.5 millimeters of rainfall was recorded in Whyte Ridge.
The storm affected different areas of the city differently, said Randy Hull, Winnipeg's emergency preparedness manager.
Environment Canada said downtown Winnipeg and parts of the city near Kildonan Park reported levels of around 55 mm.
They also said it appears the areas east of Lagimodiere Boulevard escaped the brunt of the Thursday evening downpour. Rainfall amounts ranged from 10-20 mm near the highway, trickling down to just 3-5 mm near the eastern edge of Transcona. The official rainfall reading for Thursday’s storm comes from the James Richardson Airport, where only 20.6 mm fell.
"That’s typical of thunderstorms and part of the problem in reporting rainfall amounts," meteorologist Natalie Hasell said today. "If we don’t look at different areas of the city we won’t get an accurate reading of what fell. The official report for the city is 20.6 mm from the airport. People from other parts of the city won’t have a similar number."
The deluge flooded residential streets and inspired some residents to launch canoes out onto the newly-formed waterway. Commuter routes came to a standstill near underpasses that were filled with water (underpass at Higgins Avenue and Main Street saw a handful of stalled cars swallowed up by the rising rain water) and intersections delayed by traffic light malfunction.
Siloam Mission reports that its basement has undergone significant flooding as a result of Thursday’s rain, with 26 inches (66 cm) of water in the boiler room. That has caused damage to some of the mechanical systems at the mission, and ruined various stored supplies (food, winter clothing).
The cause of the damage was the storm drains, which were backed up because of the high volume of water.
The extent of the damage is still being tabulated, officials said.
"The biggest issue will be the boiler. We’re looking at getting that dried out and checked out," Siloam Mission director Lindsay Smith said. "As for the food and clothing, we’re going through what can be saved and what can’t. We keep the food on pallets and some good shelving so there wasn’t too much lost in that regard."
It’s the second time in eight months the Princess Street mission has had to deal with unwanted water. Frozen pipes led to excessive flooding in the basement in December 2013.
As of this morning, the city fielded reports of 100 plugged catchbasins, 66 properties with clear water in the basement, 62 with raw sewage resulted from combined-sewer backups and 25 dislodged manhole covers.
Ten traffic signals are out due to a power failure, another 23 are flashing due to moisture and one is flashing due to a downed signal pole.
There's also high water in four retention ponds.
Hull said the impact on the city's drainage system would have been worse if the Red and Assiniboine rivers were as high as they were earlier in the summer.
The Red River has receded to 7.5 feet James, or one foot below the Assiniboine River walkway level - and one foot above so-called normal summer levels.
City property officials say it's to soon to tally damage to Winnipeg's new police headquarters, whose basement was partly flooded following a blown manhole cover.
Meanwhile over at Polo Park Shopping Centre, officials say things are pretty much back to normal. A few stores near the south entrance to shut down operations Thursday evening as the rainwater drifted across the floor of the popular mall.
"The only store that may remain closed today is Jersey City," said general manager Deborah Green. "They got the brunt of it. But they’re replacing the carpet and some drywall and could be back open later today or Saturday."
Green said it wasn’t a leak in the roof that caused the temporary flooding, but rather a rainwater spout coming down from the roof. The massive amount of water coming down overwhelmed the system, and flooding occurred.
More showers are expected for Winnipeg today and through the weekend, with heavier rain amounts forecast for Sunday.