We've brought Pukekohe Water Treatment Plant back into service

Our Pukekohe Water Treatment Plant is back in service today after it was severely damaged in last year’s Auckland Anniversary Weekend floods.

The floods destroyed most of the plant’s critical infrastructure, from the chemical dosing systems and drives for the pumps, to the electrical equipment in the control room.

Photo: The plant in flood

Head of water Sharon Danks says since the floods, most of Pukekohe’s water supply has come from the Waikato River – treated at the Waikato Water Treatment Plant and then distributed to the Pukekohe community.

“With the treatment plant back in service again it can provide up to five million litres a day to our customers in Pukekohe and Buckland, which eases demand on the wider metropolitan water network that serves Auckland.

“Returning the plant into service before water demand hits its peak was a top priority for us.”

The facility processes water from two bores at Hickey’s Recreation Reserve, located on Crisp Ave and Dublin Street.

“Our Pukekohe customers may notice a slight change in the taste of their water. This is because groundwater contains a variety of naturally-occurring minerals like calcium, magnesium and silica.”

Capital delivery general manager Suzanne Lucas says extensive planning went into the project before construction could begin.

“We’ve had both construction and operations staff working at pace since September to bring the treatment plant back into service.

"Instead of rebuilding the treatment plant as a mirror image of its former self, we’re spending about $4 million to reconfigure and upgrade the plant to reduce its flood risk in the future.”

Photo: Repairs being carried out as part of the upgrade

Critical components from the control room – which was severely flooded – have been moved to higher locations within the treatment plant site to make it more resilient to another flood.

“The original control room has been rehabilitated and retained for non-operational purposes.”

Lucas says to further increase the resilience of the plant, new ducts have been installed underground using a thrusting technique to better protect major electricity cables from flooding.

“Using this technique, we were able to feed and install the cabling into the ground without causing too much soil disturbance and get the work done faster.”

Lucas says over the summer Watercare will work to upgrade the treatment plant’s chemical dosing system to use self-generated chemicals.

“The plant won’t be switching over to the new dosing system until early 2025; until then the water will be treated by chemicals delivered in liquid form to effectively treat water to meet drinking water standards.”

Lucas is incredibly grateful to the construction crew and contractors for their efforts.

“We’ve managed to not only bring a flood-damaged asset back into service in such a short time but we’ve also future-proofed the plant with better design.

“We couldn’t have done all this without the support of our construction partners.”