Stink over dumping

00:03, Dec 05 2013
Roger Baldwin
HOT WATER: Roger Baldwin is planning more action to try to halt Watercare’s central interceptor project. This toilet block on Kiwi Esplanade in Mangere Bridge will be rebuilt to incorporate an air vent for the pipeline.

A project that will see much of Auckland's treated wastewater deposited into the Manukau Harbour has been given the green light.

But opponents are promising to "kick up a stink" and are meeting with a lawyer to discuss their options.

Independent commissioners appointed by Auckland Council have granted Watercare resource consent for its massive "central interceptor" project.

The development will include a 13km underground tunnel that will deliver up to two million cubic metres of sewage and stormwater to the Mangere treatment plant every year.

Water will then be treated and released into the harbour.

The tunnel will run underneath the seabed and will replace ageing pipework that is "reaching the end of its useful life", Watercare spokeswoman Belinda Petersen says.


A "significant" volume of untreated wastewater could flood the harbour if the existing pipes fail, she says.

"That consideration alone makes this a very important piece of work for us."

Watercare has also been granted consent to discharge untreated wastewater into the harbour in the event of a plant failure during a storm.

Construction on the project is expected to start in 2017.

But waterfront dwellers say the fight isn't over.

The Mangere Bridge Residents and Ratepayers group is seeking legal advice on what further action it can take to try to put a halt to the project.

Group member Roger Baldwin says he's disappointed the initiative has got the go-ahead despite residents lodging more than 450 submissions against it.

People still have grave concerns about the effect large volumes of wastewater could have on the harbour's water quality, native bird roosts and plant life, he says.

The group submitted a number of alternatives to the interceptor but is "not convinced" it got a fair hearing.

"Watercare had to show that they'd looked at alternatives but not that they'd investigated them in depth."

Fellow member Ken Duff says the project is "seriously flawed" from an environmental standpoint.

"We don't believe that the ecology of the harbour has been given proper consideration and if you don't do that, you've got a serious problem with the future of the place."

Mr Duff says the group would like to see a full public inquiry into the project before it is allowed to proceed.

Members will be presenting their alternatives to politicians in an effort to sway their opinions on the issue.

The central interceptor is expected to cost about $950 million - up from the $800m forecast earlier in the year.

Watercare spokesman John Redwood says the latest estimate has been adjusted for inflation and the rising cost of goods.


Watercare project includes:

A 13km pipeline running under the Manukau Harbour from Western Springs to the Mangere treatment plant

6km of linking sewers connecting the new pipe to existing lines

An emergency pressure relief structure that will allow untreated wastewater to be discharged into the harbour if the plant fails in a storm - an event expected to happen about once every 50 years

A number of emergency air vents that will release trapped air bubbles during major downpours, including a 3m-tall vent on Kiwi Esplanade near the entrance to Ambury Farm.

Manukau Courier