Duration: TBC

Location: Warkworth

Status: Planning

The latest

We have confirmed a solution for our planned growth pipeline through Warkworth’s town centre that keeps disruption to a minimum and has the support of local business association One Mahurangi. Our Board of Directors approved the recommendation from management at its meeting in December.

Project overview

The growth servicing pipeline is an incredibly important piece of infrastructure that not only supports new housing north of the Mahurangi River, but will significantly reduce the number of wet weather overflows into the river (and therefore the harbour). It will run from the Warkworth Showgrounds through the town centre and connect to the recently-built Lucy Moore Pump Station. It is a critical piece in the puzzle of our $450m+ Warkworth wastewater scheme that completely overhauls how the community’s wastewater is transported and treated.

The works

How will it be built?

Our preferred solution involves mostly trenchless construction through micro-tunnelling. A fully trenchless option was not possible, largely due to the topography of the land and the location of other services. Given this, we will need to install the pipe with open-trenching along Elizabeth Street and through Lucy Moore Memorial Reserve to the new pump station.

Several shafts will need to be built in the town centre to enable micro-tunnelling. The locations for these are yet to be determined. We will share this information with the community and impacted businesses as soon as we have it.

This route and methodology meets our needs in terms of our ability to maintain and operate the pipe in the long term, as well as the cost and consenting considerations

The proposed route

• Trenchless from the Warkworth Showgrounds to south side of Hill Street intersection

• Open trenching along Elizabeth Street to the Mahurangi River bridge

• Pipe crossing along the bridge over the Mahurangi River

• Trenchless installation along Queen Street/Baxter Street to Lucy Moore Memorial Park

• Open trench installation from Lucy Moore Memorial Park to the new Lucy Moore Pump Station

Timeline

We expect design and consenting to take about a year. As soon as we have more information to share – including on likely shaft locations and traffic management – we will share it with the community. Drop-in sessions will be arranged for 2025. The pipeline is expected to be in service in 2028.

Current efforts to reduce overflows

Elizabeth Street pipe upgrades

Three sections of pipes on Elizabeth Street – including the pipe bridge attached to the pedestrian bridge - will be replaced with new, bigger pipes. This work will lessen the need for ongoing maintenance and flushing, and reduce the frequency of wet weather overflows from the Elizabeth Street engineered overflow point.

From mid to late January, we’ll be carrying out topographical surveys to guide the project’s design. In February/March potholing investigations will take place.

These pipe upgrades are expected to be completed by the end of 2025.

Inflow and infiltration investigations

We have been inspecting the wastewater network and private properties to identify places where excess stormwater is getting into the wastewater network, contributing to wet weather overflows. Additional manhole sensors that will track inflow and infiltration of stormwater will be installed by Christmas 2024. These will help to identify areas that need to be investigated further.

What you can do

Ensure your roof downpipes are not connected to your gully traps, and that gully traps are sufficiently raised off the ground. This helps to keep stormwater out of the wastewater network.