Napier City Council will be carrying out a water mains cleaning programme between May 1 and the end of August.
Letters will be circulated to the residents of the affected streets to notify them of when the work will be conducted in their neighbourhood. Suburbs affected are Taradale, Greenmeadows, Tamatea, Pirimai, Onekawa and Marewa, and the work will take place on weekdays after 9am between Tuesdays and Fridays.
To carry out the work, a foam swab, called a "pig", is forced through the main, scouring it clean as water pressure propels it along before it exits the main.
Water mains cleaning is part of a routine programme of work carried out by the council every winter, when water demand is typically low, says Jon Kingsford, director infrastructure services.
This is on top of the water improvement programme which the council is undertaking at the moment.
"The material which results from the cleaning process is harmless biological matter that has settled inside the main."
Residential water supply will be unavailable for a short period on the designated day of maintenance and disruption is expected to be low, although residents may experience temporary discolouration to their water supply.
If this occurs, Napier City Council recommends flushing water through the cold water taps until the water returns to clear.
For more information on the specific areas that will be affected each day, go to www.napier.govt.nz keyword #mainscleaning.
Alternatively, The Hits 89.5 FM, Newstalk ZB 90.3FM and 1278AM or Coast 99FM radio stations will be broadcasting information about which area will be affected each day between 7am and 8:30am Tuesdays to Fridays.