Discoloured water at the tap
Run the outside tap
Watercare's advice: open the outside tap closest to your water meter and let it run for about 10 minutes to clear your private pipes.
Still discoloured? Report it
Tell Watercare through its fault reporting, and send a photo of the water if you can, so it can send a crew and track the affected streets.
Know it's safe
Watercare says the discolouration comes from corrosion inside its old pipes and the water is safe to drink, even though it looks wrong.
Onehunga facts worth knowing
Mains laid from 1910 to 1935
Onehunga's cast iron watermains went in between 1910 and 1935. Watercare began swapping them for polyethylene in April 2026 and plans to renew every cast iron main in the Onehunga supply zone within 15 years. It warns discoloured water may keep appearing while it works.
Sewers relined under Neilson Street
Watercare plans to renew wastewater pipes along Neilson Street and part of Alfred Street, mostly by relining them through existing manholes after CCTV checks. Water and wastewater services stay on throughout.
A building boom
Stats NZ counted 711 dwellings under construction in Onehunga at the 2023 Census, up from 36 in 2018. Total private dwellings went from 6,432 to 7,410.
Units and renters
Maungakiekie-Tāmaki had Auckland's third-highest share of joined dwellings in 2023, 39.2%, and 52.7% of its households paid rent (Knowledge Auckland).
Your pipes versus Watercare's
The old mains belong to Watercare; the pipe from your meter's outlet into the house is yours. If the water clears once the outside tap has run, there's nothing for a plumber to fix. A leak between the meter and the house, a dripping cylinder relief valve or a failed fitting is when to book one. Blocked sewer drain or overflow? Ring Watercare on (09) 442 2222, option 1, first.
See also leak detection, blocked drains, hot water cylinders, water pressure, and nearby Ellerslie and Māngere.
What we would do
Don't pay for a plumber to chase brown cold water in Onehunga until you've run the outside tap and, if needed, reported it to Watercare. Save the call-out for problems that really are inside your boundary, and when you book one, ask us for an authorised Onehunga plumber who handles that kind of job.