Barwon Water has begun replacing the Anglesea (VIC) outfall pipeline after it was damaged when a section of cliff collapsed earlier this year.
The repairs have been fast-tracked ahead of the busy summer period for the region.
Barwon Water said the repairs will be challenging as they will include significant onshore and offshore work. Specialist engineering and construction teams will need to consider the nearby cliffs, beach, ocean floor and tides.
A drill rig is currently boring from the water reclamation plant through the cliff. It will continue below the cliff base and ocean floor to emerge about 500 metres offshore.
Almost 700 metres of pipe are now being welded and pressure tested on land before being towed across the water to the outfall end point.
From there, the pipe will be attached to the drill head, lowed 10 metres under water and pulled back through the bore hole to the plant.
Barwon Water will work closely with local residents throughout the project.