Pipeline to Wanaka novel possibility for wastewater

Rob Darby
Rob Darby
Doubt lingers over when a solution to Cardrona's wastewater problem will be delivered, as a recent suggestion to pipe the township's wastewater to Wanaka places further delays on the release of project costings.

The Otago Regional Council (ORC) recently mentioned the concept of pumping Cardrona wastewater to the Project Pure treatment station near the Wanaka Airport, putting another option into the mix of possibilities, Queenstown Lakes District Council Wanaka project manager Rob Darby said.

The council had already been consulting the Cardrona community on a report released in May outlining the most suitable sites for a community scheme in the township.

"The possibility of a pipeline into town just added another dimension to the feasibility study," Mr Darby said.

"It sort of came from left field and slowed everything down, which is good ... what we don't want to do is have to go back and redo everything again. I can't think of much else that could possibly be envisaged so I'd like to think this is it."

Mr Darby had earlier hoped cost estimates and feasibility information on a community scheme would be developed by the council this month, but the ORC idea meant more work was required.

"It would have been quite simple to price up what was envisaged as a community scheme only, within the township ... but this [pipeline to Wanaka] is much bigger picture."

A contractor was working on costings for all options and once information was provided to the council, a report for the community would need to be formulated.

"It's going to take some time to draft it into a format which everybody can understand and make an informed decision on."

Mr Darby was reluctant to put a date on when to expect costings, but was hoping for figures before Christmas.

He said piping wastewater to Wanaka's treatment plant presented some "significant technical hurdles", combined with considerably different winter and summer flows, which raised issues over the viability of the pipeline.

Ideally, one or both of the skifields [Cardrona Alpine Resort and Snow Farm/Snow Park] would need to connect to the pipeline, "otherwise it couldn't be constructed as envisaged".

The pipeline would have to be paid for by the council rather than a developer because of the long-term investment involved.

"If the pipeline is the preferred long-term solution, the problem for the township is: when is it delivered? Is it in the next two to three years or in the next 30 years?"

An interim solution, such as a community scheme, could still be required, he said.

- lucy.ibbotson@odt.co.nz