LYNN – Commuters and parents of Pickering and Sisson school children should prepare for traffic tie-ups in the area of Broadway and Magnolia Monday when a month-long sewer project gets underway.According to Lynn Water & Sewer Operations Director Robert Tucker, the water and sewer commission will start replacing 205 feet of 24-inch, 19-feet deep sewer main on Broadway at Magnolia Avenue, where the sewer is in need of immediate repairs.Tucker said the project will take up the entire month of December and does not rule out “unexpected events that could extend the projected completion date.”The impact on the traffic in the area is going to be quite extensive and will affect traffic flow to and from Pickering and Sisson schools, he added.Crews will be working from 7 a.m. to 3 p.m. Monday through Friday. Electronic signage boards have been installed on Euclid Avenue, Broadway and Lynnfield streets, and police officers will be on duty during the project to assist motorists.Tucker said the first phase of construction will involve replacing the sewer line from the middle of Broadway to the sideline of Broadway at Magnolia Avenue. The work will result in only one traffic lane westbound on Broadway for a week. Extensive traffic delays are expected to occur during this phase of construction.Also during the project, Magnolia Avenue from Peary Street to Broadway will be open to abutters and emergency vehicles only. Vehicles leaving Pickering and Sisson schools that utilize Magnolia Avenue southbound will be redirected to Euclid Avenue.Tucker said motorists that can should seek alternative routes of travel.