The city of Portland is warning motorists to avoid using State Street at night, at least for the next two weeks, as construction crews being installing a new sanitary sewer and storm drain across State Street’s intersection with Park Avenue.

Jessica Grondin, the city’s spokeswoman, said in a statement that crews will be doing the work between 7 p.m. and 7 a.m. starting Tuesday, Aug. 15. The project is scheduled to last two weeks.

The city’s contractor, Sargent Corporation, will be required to keep one lane of traffic open during the project, but there could be delays. The contractor must have the roadway fully opened by 7 a.m. in time for the morning commute, Grondin said.

“It is recommended that motorists seek an alternate route around the work site if possible,” Grondin said.

The State Street Infrastructure Improvement project, which includes sanitary sewer and storm drains, will cost an estimated $7.6 million. The goal of the project is to reduce combined sewer overflows into Back Cove.