Sewage overflows to stop with Glen Eden underground storage tank

A giant hole is taking shape in Glen Eden.

Once complete the underground tank in Harold Moody Park will be able to hold 2 million litres of wastewater.

The $18 million dollar project is due for completion in spring 2017 and aims to reduce the amount of times that diluted sewage spills into the environment.

Watercare spokeswoman Maxine Clayton says that, when complete, an average of 10 overflow events each year in the area should be cut to less than two.

“This area of Auckland suffers regular sewage overflows during heavy rain, and the new tank and pipeline upgrades will help alleviate this issue,” she says.

Work started in mid-September on the 20-metre, 13-metre wide, tank using a caisson ring method to construct the tank as it is dug down.

A wastewater main is also being built along Glendale Rd.

The new pipes are being constructed using an AXIS guided boring system, whereby casings are jacked between a pair of shafts using a laser-guided cutting head, and waste material sucked out with a vacuum pump.

Clayton says both construction methods are not well-known in New Zealand but are used frequently in Australia and in Europe on tight building sites.

The project is being engineered by McConnell Dowell.

Harold Moody Park is the home ground for the Glenora Rugby League Football Club and chairman Aron Conlon says the tank’s construction will reduce car parks for games over winter.

Watercare has been good with keeping the club informed of how it was progressing, he says.

“It’s not ideal but there’s not much we can do about it.”

Watercare stakeholder liaison advisor Andrew Landy says the existing wastewater network is overwhelmed by heavy rain.

The new tank and pipes will cater for the population growth in the area for the next 30 years, he says.

Artwork of sea creatures created by Glen Eden Primary School students is on the fencing surrounding the work site.

The art was done in collaboration with Watercare to highlight how wastewater infrastructure helps keep beaches and waterways healthy.

Viewing windows in the fencing allow the public to see construction on the inside.

When complete, the tank will sit under the car park.

Text by Simon Smith / Retrieved from Stuff