The work will begin on Monday 10 October and is expected to take a week to complete.
Ashhurst water comes from a groundwater bore on Hacketts Road and meets New Zealand drinking water standards. However, residents sometimes receive discoloured water from the tap caused by the buildup of iron and manganese content.
The Council has installed a polishing station that has significantly improved the quality of the water but the deposits can still build up over time.
The flushing programme will remove as much of these deposits as possible across the entire Ashhurst water supply network.
During the flushing process, households may find their water pressure is a bit lower, there may be some discolouration and some properties may have no water for a few hours.
For more information please contact the Council on 356 8199.