The City of Iqaluit is asking residents not to drink the water coming from their taps unless it has been boiled for one minute.

Residents were also being asked Friday to use as little water as possible following a water main break that drained a large part of the city’s reservoir.

"We are beginning to rebuild the water in our reservoir to a level that probably by eight, 10 hours from now will probably be at their historic levels," said Iqaluit Mayor Madeline Redfern.

"We're still asking people to conserve water, to be very aware that we don't want to add pressure and take away from the fact that we're trying to build that volume back up."

Redfern says an estimated 20 million litres flooded out last night, coursing through town and flooding the area near the breakwater.

The water main burst near Inuksuk High School around midnight.

The City of Iqaluit closed all non-essential services and asked businesses to close and for people to stay home and conserve water.

City crews worked to guide the flow of the water from the broken pipe to Frobisher Bay. (Paul Moore/CBC)

"Do not use water unless you absolutely have to," said Arif Sayani, director of planning and development with the City of Iqaluit. "This is just to make sure that we can provide water to the organizations that need it, like the hospital."

Qikiqtani General Hospital was accepting emergencies only Friday morning. All schools and government of Nunavut offices were closed. The high school had been closed since Wednesday due to frozen pipes.

Shortly after the water main burst, city crews were out with heavy equipment to blast culverts and help guide the flow of the water to Frobisher Bay.

Snowmobile users in Iqaluit are being asked to stay away from the breakwater area. Run-off from the water main is creating problems with water on the ice, and large amounts of snow and ice were piled there overnight during efforts to deal with the run-off.

City and government staff were attempting to close the pipe Friday morning and Sayani said the reservoir would fill in six or seven hours.

The cause of the break is not known at this point.