The Concord School District is planning to replace the culvert over Bow Brook as soon as the state issues a permit.

The culvert is located on Concord High School property on the corner of Westborne Street and Warren Street. It needs to be replaced because the old granite started to deteriorate, said Matt Cashman, the director of facilities and planning for the school district.

Once the state approves the culvert replacement, construction is expected to take four to six weeks.

Cashman said the school district has already reviewed the plans with the city of Concord, but they are unsure when the state will permit construction. The replacement will be pushed to next summer if the permit is not approved in time.

Nobis Engineering designed the culvert, and Merrill Construction will be in charge of the replacement process.