SUSAN BOTTING/LOCAL DEMOCRACY REPORTER FOR NORTHLAND
An Auckland company wants to build a pipeline to take water from Whangarei's Wilsons Dam for a three-quarters of a billion dollar development at Mangawhai.
A new multi-million dollar water pipeline from Bream Bay to Mangawhai could soon become New Zealand's first cross-council privately-owned supply.
The pipeline from Whangarei's Langs Beach to Kaipara's Mangawhai is being investigated as water security for the booming settlement, one of the fastest-growing in New Zealand, becomes an increasing challenge.
Auckland-based Mangawhai Central Ltd, the developer behind the $750 million dollar-plus Mangawhai Central development, want reticulated drinking water. They need a signed agreement on this before October to meet construction timelines.
They are looking at a water pipeline from Langs Beach to their large-scale development in the centre of Kaipara's Mangawhai. The coastal hamlet's population is forecast to grow from around 4000 to more than 20,000 people in the next two decades.
Whangarei District Council (WDC) is looking into sending its water from Wilsons Dam in Bream Bay south down an 11km permanent pipeline and into Mangawhai.
WDC chief executive Rob Forlong said a developer had approached his council seeking answers to the constraints limited water supply was placing on developments in Mangawhai.
KDC general manager infrastructure Jim Sephton said the developer was looking for councils' support for the pipeline.
KDC looked into the implications of the pipeline, discussing this at a council briefing meeting in Mangawhai last week.
The pipeline would be the first to permanently take one Northland council's water into another's. Whangarei has previously at times provided water for Kaipara and Far North – but on a temporary basis.
Private ownership and operation of the 11km pipeline is among options being looked into.
Others include joint ownership, participation and/or involvement between the three parties or a council-only arrangement.
Sephton said ownership of the pipeline and associated infrastructure hadn't yet been finalised.
Options included the developer potentially vesting infrastructure in the council, he said.
"The initial proposition is that Mangawhai Central would retain ownership of this infrastructure (pipe) however discussions are being developed regarding the most appropriate way forward. This would involve vesting in KDC and WDC," he said.
Next month's Refining NZ's pending decision on whether to shut down oil refining at Marsden Point has a key role in the Whangarei to Kaipara pipeline.
Forlong said its prospective closure meant the potential loss of the council's biggest Bream Bay water user. Shutting down oil refining would create issues for his council as it would significantly reduce the amount of water used.
"If we have water sitting in the pipes for longer we have issues with disinfection byproducts so we either need to find additional users for the water or adjust our processes and infrastructure to deal with the reduced consumption," Forlong said.
Whangarei ratepayers have funded Wilsons Dam and pay rates towards their district's publicly owned reticulated drinking water.
The pipeline would carry about 1000 cubic metres of water each week from Whangarei into Kaipara. Whangarei drinking water is already piped as far as its south-eastern Langs Beach boundary.
Sephton said the developer had offered to increase the pipe size by 67 per cent to future proof water supply for other Mangawhai development. A tank filling site would also be considered.
He said the pipeline would bring longer term benefits of getting reticulated water to development across wider Mangawhai.
KDC deputy mayor Anna Curnow and some other councillors at last week's meeting responded cautiously to the new facility's potential private ownership.
In contrast Mangawhai councillor Peter Wethey said it was a good move.
Private pipeline ownership and or operation could be contrary to the intent of the Government's Three Waters sector shake-up which includes drinking water.
The future ownership of more than a billion dollars of Northland's ratepayer-funded Three Waters infrastructure will likely be put into public ownership in a giant top-of-New Zealand entity.
A developer wants to take water from Whangarei District Council's Wilsons Dam, above, to supply the $750 million dollar-plus Mangawhai Central development.
The pipeline would bring longer term benefits of getting reticulated water to development across wider Mangawhai.