Perth Road 139 culvert replacement to close road near St. Marys for up to three weeks

By Galen Simmons

Drivers travelling southeast of St. Marys can expect a temporary road closure later this summer as Perth County replaces a deteriorating culvert on Perth Road 139.

At its July 2 meeting, Perth County council awarded the construction contract for the culvert replacement project to Wellington Construction Contractors Inc. after the company submitted the lowest compliant bid of $322,000, excluding HST. The work is part of the county’s 2026 capital program for repairing and replacing small culverts.

“This asset is prioritized for remediation under this contract to repair an existing road crossing, which is comprised of concrete and stone box culvert structure with corrugated steel-pipe extensions on each of its ends,” director of public works Bill Wilson told council.

The project will see crews repair and replace portions of an aging culvert located on Perth Road 139, in the Township of Perth South just southwest of Line 2 near Prospect Hill. The work will replace the damaged culvert sections, repair the existing concrete and stone structure, restore proper water flow and protect the roadway from future erosion and undermining.

“Engineering field reviews indicated that the CSP culvert ends are badly deflected, the east end of the culvert structure has effectively failed and remediation of the asset is critical in order to replace the compromised components and stabilize the barrel of the structure.”

To complete the work safely and efficiently, Perth Road 139 will be fully closed at the construction site for a maximum of 21 days.

County staff considered maintaining one lane of traffic during construction, but determined a full closure would reduce project costs, improve worker safety and shorten the overall construction schedule.

The closure will take place sometime between July 15 and Oct. 30, though an exact construction start date has not yet been announced. Environmental regulations governing work within the watercourse prevent construction from beginning before July 15, while the contract requires the project to be completed by Oct. 30.

During the closure, motorists will be directed around the work zone using a signed detour along Perth Line 4, Perth Road 151 and Whalen Line.

The county says it will provide advance notice of the closure through project signage, electronic message boards, its website and social-media channels as construction approaches. Residents can also expect updates throughout the project as work progresses.

The culvert replacement is expected to be completed within the approved $600,000 project budget for small culverts in the county’s 2026 capital budget.