Lane closures will go into effect Aug. 26.
A vehicle crashed into a utility pole, closing Stedman Street into the evening.
The water main break is in the area of Graniteville Road and Pilgrim Road.
Chelmsford police said a motorcycle and a sport utility vehicle collided on Acton Road. The motorcyclist suffered life-threatening injuries.
Multiple lanes will remain closed as repairs are expected to last several hours.
Latest Chelmsford traffic: a bad crash involving a tractor-trailer on Interstate 495 near Route 3.
Massachusetts police are losing patience with drivers refusing to clear more than a foot of snow from their cars before hitting the road.