Taps ran dry and toilets backed up in mid-morning after maintenance work on a city water line supplying Parliament Hill reduced pressure to a trickle. The disruption prompted some MPs to quip about "things piling up," and odours began circulating in the centre block.

Government House Leader Peter Van Loan eventually announced an early adjournment.

He said the sergeant-at-arms had determined the lack of water was a threat to the health and safety of employees and MPs.

The decision cancelled afternoon tours in mid swing, with guards herding students outside the main doors.

"There's also a shortage of hot air," joked Conservative MP Scott Reid. "We can't go on too long without that either."

Fisheries Minister Loyola Hearn, heading up an elevator after question period, said there was a serious side too.

"Apparently, it's in case we have a fire," he said of the shutdown.

Water was expected to be flowing again by early evening.