Norwich — A small section of Chestnut Street at the Bath Street intersection will be closed around the clock from April 27 through May 1 to allow Norwich Public Utilities and Norwich Public Works crews to replace a failing, aged sewer pipe and 110-year-old stone box culvert.

Bath Street, a one-way street heading toward City Hall, will be closed during the day during the project, but will reopen at night.

While the work on the 90-foot section of roadway will not disrupt water or sewer, gas or electric service, the road closure will require a complicated detour system because of the myriad of one-way streets in the immediate area.

Traffic from McKinley Avenue and Franklin Street heading toward the City Hall area will be routed up Willow Street to Broadway. That intersection, however, is just past City Hall on the one-way portion of Broadway heading away from the building. To return, traffic would travel up Broadway a short distance to a left onto Crossway Street and an immediate left onto Union Street — a one-way heading toward City Hall.

Vehicles departing the City Hall area would take the same route to make their way to Main Street.

NPU spokesman Chris Riley said detour signs will be posted.

“It will be challenging, but we’ll save at least half as much time by doing it this way,” Riley said.

In the $100,000 project, NPU and contractor crews will replace approximately 90 feet of a 30-inch combined sewer and storm water line that runs along Bath Street. The pipe is located about 10 feet below street level, requiring crews to dig deep trenches mostly by hand to reach the pipe, Riley said.

The pipe being replaced is older and showing preliminary signs of failure, and the stone box culvert over the system dates back about 110 years and also will be replaced. The project is not part of the larger NPU effort to separate sewer and storm water pipes, but is being done to repair the failing pipe, Riley said.

“It is more practical, safe and cost-effective for this work to be done in a staged and scheduled manner and not in response to an emergency,” he said.

c.bessette@theday.com

Twitter: @Bessettetheday