With upgrades to the town’s water treatment plant now underway, another programme of water pipe flushing is starting in Rahui Pookeka Huntly to address the recurring issue of water discolouration.
The muddy-coloured water is caused by naturally occurring elements in the source supply and while it doesn’t look nice, it remains safe to drink and meets all water safety requirements.
IAWAI’s Waikato General Manager Operations Keith Martin says it’s a historic and ongoing issue but he understands the frustrations of the local community.
“We would love to have a simple and immediate long-term fix, but that’s just not possible. We are making operational pressure and supply changes to respond. We are aware of community commentary but we request people contact IAWAI or council directly – that way we can plan pipe flushing but also build a record of issues for planned future works.
“This has been an issue for decades, but we aren’t ignoring it.
“Council flushed 34km of pipes last year and we’re starting the programme again as we work on interim plant upgrades which will deliver some big improvements ahead of next summer.”
The interim upgrades at the treatment plant are specifically to target removal of iron and manganese from the supply through additional filtration. These works are scheduled to be finished by June 2027.
Water supply for the town comes from the Waikato River below the Mangawara Stream in Taupiri, a stretch of water which is high in iron and manganese. The current water treatment process does not fully capture these minerals and chlorination (to kill germs and bacteria) can cause the iron manganese to build up deposits in the pipes.
Ironically, much-needed upgrades to the pipe network can cause a temporary resurgence of the issues, as the network is repressurised following repairs or maintenance, dislodging iron and manganese deposits and leading to discolouration of tap water.
Longer term, the IAWAI Water Services Strategy plans a new sub regional water treatment plant based in Ngaaruawaahia from 2029. This will serve Hamilton, Ngaaruawaahia and Raahui Pookeka Huntly.
The pipe flushing programme is responding to localised ‘hot spot’ areas and anyone having brown water issues can call 0800 WATERS (0800 928 377), contact their local council or report it on the Antenno app.
Pipe flushing will again be carried out in Huntly using a NO-DES (Neutral Output Discharge Elimination System) unit to flush and remove mineral deposits from the water pipes. The technology connects hydrant-to-hydrant, using reverse-flow flushing to remove iron and manganese deposits from water lines. The process filters out debris with minimal water loss and was part of a programme to flush 34km of pipes in Rahui Pookeka Huntly last year.