$11.3m power upgrade boosts resilience at our Waikato Water Treatment Plant

Transformer in final position

Our team and Counties Energy have completed a major project that will play a critical role in ensuring the resilience of Auckland’s water supply. The $11.3m project to construct dedicated electricity infrastructure to supply our Waikato Water Treatment Plant was completed this month.

Our construction delivery manager Alrick Sargent says the Waikato Water Treatment Plant plays a significant role in Auckland’s water supply.

“This treatment plant currently supplies about 20 per cent of Auckland’s water – and we do rely on it more in the summer months when people are using more water.
“It’s a critical part of our wider water supply scheme, so having a stable and resilient power supply to the treatment plant is really important. Without power, we can’t treat any water from the Waikato River, and even short outages create problems for the treatment plant’s operation.
“As it is located in a rural area, the power supply feeding the plant was often affected by faults on the long overhead power lines, with anything from a complete outage to brief voltage disturbances that can affect our equipment on site.
“That’s why we’ve worked with Counties Energy on this extensive upgrade to ensure the treatment plant’s power supply is more stable and resilient.”

Transformer connected to the substation
Counties Energy developed a solution to meet our needs through an approach that ensures redundancy and resiliency of supply and improved power quality. The company has installed dedicated network for the plant, including a 40MW transformer at its 110kV Tuakau Substation and a 7km underground 22kV cable from the newly constructed 110kV Pokeno Substation. 
Both feeds can support the plant independently at any time from the two substations, providing a full back-up power supply. The solution also improves voltage stability.
The upgrade also provides additional power capacity that will support future upgrades of the treatment plant to enable it to treat more water as Auckland’s population grows.
Counties Energy chief executive Judy Nicholl says the consumer-owned lines company is highly experienced and fully committed to delivering essential services to a key piece of our essential infrastructure. The infrastructure issues that New Zealand faced from Cyclone Gabrielle illustrates the need for utilities to work together to improve the resilience of critical public infrastructure as climate change drives more extreme weather events.
“As an electricity distributor with nearly 100 years’ experience in working in our region on large network builds, we’re extremely proud to utilise our infrastructure and network expertise to supply a dedicated solution to benefit the entire Auckland region into the future. The new network ensures increased power capacity, reliability, resilience and power quality to Watercare’s Waikato Water Treatment Plant, guaranteeing a critical path in the journey of supplying a quality water supply to the nation’s largest city.”