Watercare kicks off extensive wastewater network upgrades for Warkworth

Watercare is embarking on an extensive upgrade of Warkworth’s local wastewater pipes that will help to keep rain out of pipes and reduce the likelihood of overflows in wet weather.

The project complements Watercare’s $450m programme of works that is transforming how wastewater is transported and treated for the Warkworth and Snells/Algies beach communities.

Watercare project manager Isileli Aholelei says work will begin this month to inspect the public wastewater pipes in the streets north of Elizabeth St, where a bottleneck exists in the wastewater network.

“We’re focussing on the area upstream of Elizabeth St because if we can reduce the amount of stormwater getting into the network when it rains, we’ll reduce the likelihood and volume of overflows that can impact the Mahurangi River.

“We’ll start with CCTV inspections of the pipes so we know exactly what we’re dealing with. Many of these pipes were built in the 1960s and 70s, so there will be cracks and deterioration.

“Over the next few months, we’re expecting to reline about 3.5 kilometres of pipes. Relining is as good as a full replacement but is far less disruptive. It’ll extend the lives of these pipes by another 50 years and help to protect the environment.”

After flushing the network to remove debris, the pipes will be relined using a trenchless ‘cured-in-place pipe’ method.

“This involves inserting a flexible liner into the pipe via one manhole, which is then pulled through to the pipe’s next manhole.

“The resin-soaked liner is then expanded and pushed against the original pipeline, filling any cracks. We use UV lights to cure and seal it, creating a durable, leak-proof inner tube.”

Watercare completed a similar project in the southern part of Warkworth in early 2024.

Aholelei says most of the work will have only minor traffic impacts.

The work is part of a targeted $12 million wastewater renewals programme aimed at strengthening network resilience and addressing issues across Auckland’s 8800-kilometre wastewater network.

“Our crews have just finished a similar project in Beachlands and Maraetai, so they’re a well-oiled machine when it comes to upgrading the local wastewater network. They’re looking forward to getting started in Warkworth.”

Update on the growth-servicing pipeline

Work began in the new year on the last of five projects that together form Watercare’s $450m+ Warkworth Wastewater Scheme, says chief operations officer Mark Bourne.

“The Warkworth growth-servicing pipeline is the highly-anticipated final piece in the puzzle of our $450m investment programme for Warkworth and the Snells-Algies communities.

“Once complete, this pipeline will almost eliminate wet-weather overflows to the Mahurangi River and support growth in northern Warkworth, so it’s an incredibly important piece of infrastructure for the region.”

Last year, Watercare opened the state-of-the-art Snells Beach Wastewater Treatment Plant and ocean outfall, and commissioned the Warkworth Street Pump Station and transfer pipeline.

Preliminary work for the Warkworth growth-servicing pipeline began in January to enable the relocation of existing utility services.

The pipeline has been split into two stages to deliver the environmental outcomes sooner. We’ll complete stage one – the Elizabeth St section being installed with open trenching – by December this year. When it’s in service, it will resolve the bottleneck in the network that’s driving wet-weather overflows.

The second stage of the pipeline is expected to be completed and in service in 2027. This will support development in northern Warkworth.