The City of Winnipeg is describing Thursday night's rainstorm as a one-in-100-year event.
The nearly 180-minute storm, which cut a swath of rain across Winnipeg from the southwest to the northeast, dropped 102 millimetres on the southwestern Whyte Ridge neighbourhood and also walloped Linden Woods, Tuxedo, River Heights, downtown and parts of the North End.
Rainfall amounts in southwestern Winnipeg ranged from 50 mm to 82 mm but other areas of the city were barely drenched, Environment Canada readings showed. The official rainfall reading for Thursday's storm at James Richardson International Airport was only 20.6 mm. Western reaches of Transcona, meanwhile, received 10 to 20 mm and the eastern edge of the city received three to five mm.
"That's typical of thunderstorms and part of the problem in reporting rainfall amounts," Environment Canada meteorologist Natalie Hasell said Friday.
"If we don't look at different areas of the city, we won't get an accurate reading of what fell."
The deluge flooded residential streets and inspired some residents to launch canoes onto the newly formed waterways.
Commuter routes came to a standstill near underpasses filled with water and intersections delayed by traffic-light malfunctions. As of Friday, 10 traffic signals were still out because of a power failure, while another 23 were flashing because of moisture. Another flashed because of a downed signal pole, said Winnipeg emergency preparedness director Randy Hull.
The city also fielded reports of 100 plugged catch basins, 66 properties with clear water in the basement, 62 with raw sewage from combined-sewer backups and 25 dislodged manhole covers, said Hull, adding water levels are high 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. There were temporary rises in the river levels in the city -- the Red River rose approximately 0.6 feet and the Assiniboine River rose approximately 1.5 feet. The Red River stood at 7.5 feet James on Friday. That's one foot below the Assiniboine River walkway level and one foot above normal summer levels.
A dislodged manhole cover led to rain seeping into the basement of the new Graham Avenue police headquarters, where Manitoba Hydro ordered an emergency power-down before vacuums were carted in to remove water, said Caspian Construction president Armik Babakhanians.
City property officials said it's too soon to tally damage to the police headquarters. The damage is not expected to delay the movement of Winnipeg Police Service personnel from the Public Safety Building on Princess Street into the new structure, city spokeswoman Michelle Finley said in a statement.
Hull said the damage to city property paled in comparison to the damage to private property.
Downtown's Siloam Mission, for example, reported 66 centimetres of water in its boiler room, damage to mechanical systems and ruined food and winter-clothing supplies. "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.
In Tuxedo, staff at Rumor's Restaurant and Comedy Club were forced out of the basement venue after water began to rise in the interior.
The club will be closed for two weeks, a spokeswoman estimated.
A single store at Polo Park shopping centre, Jersey City, remained closed after rainwater spilled inside the mall, general manager Deborah Green said.
"They got the brunt of it. But they're replacing the carpet and some drywall and could be back open later today (Friday) or Saturday," she said.
-- With files from Free Press staff