A ruptured 16-inch water main beneath Gay Street downtown has "undermined the street surface," forcing its closure, according to the Baltimore Department of Public Works.
"We can't let traffic ride over it," said Kurt Kocher, a department spokesman, who said crews had already opened up a rectangular, 4-foot by 6-foot hole in the asphalt just south of Saratoga Street to begin pumping out the leaking water.
The road remained closed into the Thursday morning rush hour and was expected to remain shut down through the morning, complicating traffic and diverting buses, DPW and Baltimore Department of Transportation officials said.
The closure began Wednesday and impacted the Wednesday evening commute.
"It's going to be closed through rush hour, so we're going to be doing some maneuvering," Adrienne Barnes, a transportation department spokeswoman, said Wednesday.
Officers diverted traffic onto Fayette Street, officials said. Multiple bus routes that use Gay Street in the area, which is close to City Hall, will have to be rerouted, Barnes said.
Traffic on Lexington Street will be allowed to cross Gay Street, but not turn onto it, officials said. The Maryland Transit Administration bus stop located at Gay and Lexington streets will be closed until Gay Street reopens.
The transportation department "strongly encouraged" drivers to avoid the area. Those who usually use Gay Street to access the Jones Falls Expressway should instead use Charles Street or the Madison Avenue and Fallsway ramps.
Water service is being maintained through the afternoon for the many businesses and city offices in the vicinity of the rupture, but was turned Wednesday night as repairs begin, Kocher said.
Until service is stopped, crews will be diverting the water leaking from the rupture into a nearby storm culvert, Kocher said.
"Is the street going to be any worse with letting it run? Really no, with the pumps there," he said.
The eventual shut off of water service will affect businesses and offices located on Gay Street between Water and Orleans streets and those within the square block bordered by Gay, Saratoga, Lexington and Holliday, Kocher said.
Kocher said the repairs would hopefully not last into Thursday, but he couldn't give an estimated time for their completion.
"We have to get down there, shut [the water] off, see how it's broken, see if it's going to need clamping or will need a new section of main," he said.
The number of pipes that have broken in the cold this winter was not available Wednesday, but DPW officials say they're down from last year, when 353 water mains broke in January alone, the equivalent of four normal months.
"Compared to last winter, this winter hasn't been as bad," Jeffrey Raymond, another DPW spokesman, said.
Baltimore Sun staff reporter Colin Campbell contributed to this article.
twitter.com/rectorsun