Below the surface of the Chelsea Sugar Refinery landfill in Birkenhead sits critical infrastructure for the community.
The stormwater pipe is vital to the surrounding neighbourhood but has reached capacity.
In August 2017, a renewal project commenced to replace the pipe, enabling greater capacity and better environmental outcomes.
“This $9 million project is a great case of ‘iceberg investment’,” says North Shore Ward Councillor Chris Darby.
“The majority of it sits below the surface where we can’t see it and don’t think about it, but its effects are astounding.”
The new 2.1-metre diameter pipes will prevent sediment and contaminants going into Chelsea Bay and will provide improved hillside stability in the surrounding landfill area.
“The result is that we will be able to largely eliminate landfill contaminants reaching Duck Creek pond and the downstream harbour. We’re also future-proofing for growth – the new pipe will triple stormwater capacity in the area."
The Birkenhead project, which is expected to be complete in early 2019, has employed methods and techniques made popular by other well-known Auckland projects.
“The expertise used to build the new pipe is the same that was used in the Waterview tunnel, with a large underground boring tunnel,” says Cr Darby.
“This makes way for 550 metres of new pipes underneath Chelsea Estate.”
New, smaller, pipelines are also being installed at Huka Road and Rawene Road to safely channel stormwater runoff away from the Chelsea Estate landfill site.
