A major Portland thoroughfare and intersection will be closed to traffic beginning Thursday to allow construction crews to install a new sanitary sewer, storm drain, as well as water and gas mains.

Jessica Grondin, spokeswoman for the city, said in a press release issued Tuesday that the intersection of Cumberland Avenue and State Street will be closed for one month. State Street between Cumberland Avenue and Deering Street will also be closed for 30 days.

Motorists are being advised to avoid those areas and find alternative routes. The construction work will take place between 7 a.m. and 7 p.m. Monday through Friday and from 8 a.m. to 7 p.m. on Saturday.

Grondin said the contractor will be required to maintain access for local traffic on State Street and its side streets during the construction period.

The construction work is a part of the State Street Infrastructure Project, whose goal is to reduce combined sewer overflows into Portland’s Back Cove.

Sargent Corp. is the project contractor. The project, which is estimated to cost about $7.6 million, is scheduled to be substantially completed by Dec. 31 with final roadway paving expected to occur in the spring of 2018.