PORTLAND — A 1.4-mile-long section of Baxter Boulevard – the two-lane road that curves around Back Cove and the city’s popular waterfront walking trail – will close later this month and will not reopen for at least eight months.

Electronic billboard signs were erected on Baxter Boulevard this week flashing alerts that warned motorists and trail users that the road would be shut down to traffic starting Wednesday, Jan. 30.

The road closure will affect the section of Baxter Boulevard between Vannah Avenue and Bates Street.

Nicole Clegg, the city of Portland’s spokeswoman, said the walking trail, which attracts hundreds of walkers, joggers and bicyclists daily, will remain open during the $10 million construction project.

Clegg said the city needs to close the road so that it can install two 1,700-foot-long underground concrete boxes – known as storage conduits – each with the capacity to store up to one million gallons of sewage and storm water.

The project will be funded entirely with sewer user fees, Clegg said.

The city had hoped to begin the project in November but Clegg said it took longer than anticipated to obtain permits from the Maine Department of Enviromental Protection.

During a heavy rainstorm, rainwater flows into the city’s sewer system creating what officials call stormwater overflow. Under the present system, the overflow is discharged untreated into Back Cove.

The giant storage boxes will have the capacity to capture more stormwater before it can enter Back Cove. The polluted water will eventually be transferred to the East End Wastewater Treatment Facility.