Winnipeg city crews are cleaning up from a massive watermain break that flooded an underpass and caused serious traffic problems on Portage Avenue Thursday morning.

The watermain broke at around 9 a.m. Thursday, forcing the nearby St. James Hotel to close for the day as crews clean up.

Paul Trevenen told CBC News he was driving by the hotel when he saw water gush into the parking lot.

"You know The Beverly Hillbillies, where the oil's popping out of the ground? That's basically what it looks like," he said.

"The asphalt had buckled and all the water was pouring out into the parking lot [and] onto the street and down onto Route 90 as well."

CBC News cameraman John Bronevitch said the Route 90 underpass and Portage Avenue looked like a "little lake" after the break occurred.

"It's filling up right now. I mean, it's maybe three to five feet right [deep] now," he said that morning.

A watermain break flooded the Route 90 underpass near Portage Avenue Thursday morning. (John Bronevitch/CBC)

St. James Hotel owner Lawrence Maksymetz said most of the water was in the basement and on the main floor.

"There was water in our basement, in the restaurant and so forth," he said.

"It's quite a mess right now. There's quite a bit of mud in the parking lot here, so we have to close down the hotel."

Southbound Route 90 at Ness Avenue was closed for several hours, and there was no access to Route 90 from westbound Portage Avenue. The area reopened to traffic by around 2:30 p.m., according to police.

City crews said the break was under control, but the roadway was still being cleared of slush and ice on Thursday afternoon.