Riders along the Main Yarra Trail in Richmond should keep on the alert for a small drilling rig in early July.
Melbourne Water and its contractors are undertaking soil investigations around the vicinity of the Hawthorn Sewer, which goes under the Yarra.
The trail will remain open during the three days of works, although the width of the path will be reduced.
Signage and traffic controllers will raise awareness of the changed conditions.
After working hours the machine will be moved so that the path returns to normal width.
Investigation works will not impact the shared path current surface condition.
The location is north of Bridge Road bridge on the Richmond side of the Yarra.