MONROE — The section of Route 34 located on a bridge positioned atop the hydroelectric Stevenson Dam will be closed to traffic for an extended period to allow for maintenance on the dam’s floodgates.

The road closure is planned to last for a total of 90 hours. The Route 34 road section atop the dam will be closed starting at 6 am on Saturday, June 27, with the closure continuing for all of Sunday, June 28, Monday, June 29, and Tuesday, June 30.

Many Newtown motorists use the Route 34 bridge, which links Monroe to Oxford, in traveling to and from the New Haven area.

Most of the dam maintenance will be done throughout the weekend, but the closure may affect commuters during both the morning and afternoon rush hours on Monday, June 29, and Tuesday, June 30, according to FirstLight Hydro Generating Company, which owns the dam.

If workers complete their maintenance early, the bridge would be reopened to traffic earlier than planned.

Traffic that would normally travel on the bridge atop the dam will be detoured using State Route 111, State Route 110, and Bridge Street in Shelton. Long-distance traffic is advised to take Route 8 and Interstate-84 to avoid Stevenson Dam.

Motorists are advised to follow the posted detour signs and follow the directions of the uniformed police officers.

Stevenson Dam started hydroelectric operations in 1919. The bridge atop the dam is one of the few Housatonic River crossings in this area.