Photo: RNZ / Cole Eastham-Farrelly
Pukekohe residents may notice a change in the taste of their tap water which is no longer coming from the Waikato River.
Watercare said a water treatment plant that was badly damaged in last year's flooding is now back in service, pumping five million litres of groundwater water a day from two bores.
The community's water has been drawn from the Waikato River and treated in Waikato since storms destroyed most of the plant's critical infrastructure in January 2023.
Its head of water, Sharon Danks, said the plant 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."
She said returning the plant into service before water demand hits its peak was a top priority.
"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."
Last year's 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.
Watercare said repairs and upgrades cost $4 million.
Capital delivery general manager Suzanne Lucas said extensive planning went into the project before construction could begin.
"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," she said.
"We couldn't have done all this without the support of our construction partners."
Lucas said since September, construction and operations staff worked 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 $4m to reconfigure and upgrade the plant to reduce its flood risk in the future."
She said 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 said 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."
She said over the summer, Watercare will 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."
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