City crews have replaced a water main that fractured and burst over the weekend and say they hope to have the road open in time for Tuesday's morning rush.

Crews responded to the break on Sunday and closed down all three lanes of southbound Crowchild Trail between 32 and 33 Avenues to excavate.

A two foot section of pipe burst under the roadway and when crews dug down they discovered a crack that ran a total length of six metres or 21 feet along the main.

The break is the largest water main break city crews have ever had to deal with.

The city says that everyone who regularly uses the road during their commute should choose a different route for the ride home on Monday.

The new section was tested on Monday afternoon and the city says water is flowing through it once again.

Crews will spend Monday evening backfilling the hole with almost 230 tonnes of asphalt and will then repave the road.

The northbound lanes are open to traffic and the city hopes to have the southbound lanes reopened in time for Tuesday's morning commute.