There will be limited parking and pedestrian traffic in Picton to allow for some trees to come down.
The work will affect County Road 22 south of London Avenue to Old Church Street, as well as Church Street up to York Street.
There are traffic controls in place.
The work is scheduled to continue until Friday and will take place between 7 a.m. and 6 p.m.
This is part of the Picton Heights Reservoir Watermain Improvement Project.