Two new watermains providing drinking water to the Glenbrook Beach community are now in service – a significant milestone in Watercare’s $6.3m project to futureproof the area’s water services.

Instead of opting for a like-for-like repair of a damaged watermain crossing the Taihiki Estuary, Watercare saw an opportunity to deliver infrastructure that future-proofs both local water and wastewater networks.

Watercare project manager Sean McHenry says when planning the replacement of the pipeline, Watercare factored in the community’s future needs and opted for a dig-once approach.

"Instead of building just one new watermain, we’ve installed two new watermains and a wastewater pipeline directly underneath the estuary.

“To achieve this, we used horizontal directional drilling (HDD), a method commonly used to install underground cables and pipelines.

“We drilled all three pipelines 15 to 20 metres underneath the estuary bed and connected them into the existing networks at Tahuna Minhinnick Drive and Waitete Pā.

“By installing them this way, we reduced soil disturbance and environmental erosion and there’s now no risk of marine activities damaging these assets within the estuary.

“It’s also way less risky as it eliminates the need for manually anchoring the pipelines to the estuary bed.”

McHenry says it took ground crews six months to install all three pipelines and eight hours to bring the watermains into service.

“On the day, we had five crews working in sync with each other to get the job done; two crews on either end of the watermain and one carrying out the meter connections to the new pipelines on Tahuna Minhinnick Drive.

“By having multiple crews on the ground working in coordination, we were able to commission both pipelines at pace and without interrupting the community’s water supply.”

McHenry says each of the 750m wastewater and watermain pipelines have been successfully installed. However, only the two watermains were brought into service.

“The new wastewater main will be brought into service when required to service future commercial and residential development.”

McHenry says with the watermains now in service, Watercare’s focus is to complete the remediation works and remove the temporary watermain from across Taihiki Estuary.

“Over the next few weeks, we’ll be topsoiling and grass seeding and infilling areas across both laydown sites.

“We are also working to remove the temporary pipeline from the estuary before the end of summer.

“We’d like to thank the community for their patience while our ground crews have worked to deliver infrastructure that improves your current and future water services.”

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