The waterway running beneath the Grand Bend Bridge is closed until October 3.
Lambton Shores crews are working to complete phase two of the Ontario Street Bridge Construction project, and the closure will allow for the placement of a barge and equipment required for demolition.
The work is aimed at reducing congestion and improving traffic flow through Grand Bend.
It was initially hoped the project would extend the bridge's lifespan by another 60 years.
The $7.63 million project includes the conversion of the bridge deck from four lanes to five lanes, with a dedicated right turn lane at the main intersection to ease traffic congestion.
It will also see multi-use paths constructed on either side of Ontario Street.
Phase one was completed ahead of schedule in May, and phase two is expected to be finished by spring 2026.
The Ontario Transportation Ministry has chipped in $5 million toward the enhancements, with the municipality funding the remainder.
More details can be found by clicking here.