City workers said they believe a contractor may have drilled into a water main early Friday morning, causing the road to collapse. (Ryan Gibson/CBC)

A downtown section of Elgin Street southbound is expected to remain closed until Saturday morning after a water main break early Friday created a large sinkhole.

Earlier Friday, the city said the road would reopen by about 4 p.m. Then, in the early afternoon, the city said the road would reopen at about 8 or 9 p.m.

By 6 p.m. Friday, the city said the road is expected to remain closed until Saturday at around 8 a.m.

Water service was partially affected at the Ottawa courthouse, and was expected to be restored Friday afternoon.

A section of Elgin Street just south of Laurier Avenue collapsed after a private contractor accidentally drilled into a water main early Friday morning while trying to install a gas line, Mayor Jim Watson said.

Elgin Street southbound is closed from Laurier to Nepean Street and northbound traffic in that section is reduced to one lane. City buses that normally travel that stretch of Elgin will be rerouted to O'Connor Street.

"There is a cost because it's not only our city crews that are there, police are there and buses have been rerouted, but we'll be sending a bill to the contractor that is responsible because it shouldn't be the taxpayers that pay for a private contractor's error," Watson told reporters Friday.

Ottawa water services supervisor Chris Hamilton said that at about 2 a.m. Friday morning, a river of water was flowing from the spot at Elgin and Laurier.

About four feet of water was reported in the parking garage of the highrise building at 66 Slater St., just northwest of the intersection.

At the Lord Elgin Hotel, muddy water flowed onto the sidewalk in front of the building before heading down Slater, said guest services manager N. Ravi.

"Crews were on the spot within about 15 minutes," Ravi said. "They had a lot of excavators and things in front moving the mud, which caused a lot of disturbance to the guests in the hotel. Se we had a fair amount of complaints from guests from the hotel. We had about eight or 10 guests who had to move rooms at two in the morning."

The crews agreed to stop working at 3 a.m., and resumed work at 5 a.m., Ravi said.

Watson said the damaged pipe was installed in 1998 to 1999.