Water pressure is back to normal in Kitchener’s south end following a water main break that affected a wide area and caused Conestoga College to shut its doors.

The break occurred around 11:15 a.m. Friday on Old Carriage Drive, near Homer Watson Boulevard and Pioneer Drive.

It took crews several hours to locate and isolate the break – a period during which low water pressure was felt as far away as Conestoga College’s Doon campus.

“As soon as we ascertained that it was not a campus issue … we had to close the campus,” college vice-president Kevin Mullan tells CTV News.

In addition to not having water for washrooms and other regular uses, Mullan says, the school’s sprinkler system was running dry – which meant keeping the campus open would run afoul of health and safety procedures.

Mullan estimates that there were about 8,000 students in the school at the time of the closure, and 3,500 vehicles in the parking lot.

That volume of traffic exiting at once sent both the campus and the surrounding neighbourhood into states of gridlock.

Student Ryan Dietrich found himself waiting in his car for over an hour without getting off school property.

“They were really quick to get us out of the school, but it’s taking us forever to get out of the parking lot,” he said.

Once the break was isolated, city crews were able to restore normal water pressure to most of Doon.

An apartment complex and a series of homes on Old Carriage Drive remained without water.

“We’ve got about 130 residents that are going to be without water until approximately 9 p.m. tonight,” says Tammer Gaber, Kitchener’s manager of operations.

By 6:30 p.m., water was reported as once again running on Old Carriage Drive.

If residents see milky water coming out their taps when normal water pressure returns, Gaber says, they should keep the taps running long enough to flush out their pipes.

The cause of the break has yet to be determined, but officials suspect it may have something to do with rapidly warming temperatures.

With water pressure back to normal, the Conestoga campus reopened late Friday afternoon for arena and gym rentals.

School officials say all buildings will be open as normal Saturday.