Watercare is carrying out a $1.5 million project in Murrays Bay to permanently repair damage caused to the local wastewater network caused by the Auckland Anniversary Floods.
The repairs around Penguin Reserve will see the removal of a temporary bypass, pump and generator behind Dalmeny Close, and extensive gravity bypasses behind Penguin Drive.
To reduce environmental impact of the work and to protect the pipelines, they’re being installed using horizontal directional drilling (HDD) and micro tunnelling.
Temporary pump and generator bypasses were installed across seven neighborhoods in Auckland after the Auckland Anniversary and Cyclone Gabrielle flooding in early 2023, with dozens more temporary gravity bypasses in isolated areas to maintain essential wastewater services.
These temporary measures protected public health and the environment, while giving Watercare and its contractors the time needed to design and implement permanent, more resilient solutions that would strengthen Auckland’s wastewater network.
Capital delivery general manager Suzanne Lucas says the intensity of the storms caused numerous landslips, some of which took out watermains and wastewater infrastructure across the region.
“They caused an enormous amount of damage to our networks – particularly to the wastewater network in hilly areas of Auckland in the north and west, and the infrastructure in our western dam catchments,” she said.
“Now, two years and five months later, we are nearing the home stretch of our $80 million flood recovery program, with many of the permanent solutions across Auckland now installed.”
Construction delivery manager Johan Gerritsen said the permanent solution at Penguin Reserve involves installing wastewater pipelines within the crown of the reserve.
“One pipeline will stretch 100m between Dalmeny Close and East Coast Road, and the other will run 98m from the Penguin Reserve entrance on Penguin Drive to Bellbird Rise,” he said.
“We will also be installing a 40m pipeline to permanently reconnect a homeowner back to the network after being disconnected following the floods.
“These new wastewater lines will replace the temporary repairs that were installed after landslips destroyed the original infrastructure.
“Through an extensive investigation and design period we were able to find a solution that moves the assets away from flood-damaged areas and remediate an area of the network that’s needed a lot of maintenance in the past.
“These methods allow for both pipelines to be installed at depths between two and eight metres in the valley reserve, where the ground is more stable and better protected from slips. It also helps to minimise impacts to homeowners, surrounding properties and native vegetation.”
Watercare aims to have the permanent flood recovery repairs installed by the end of August.
Do you have news for the international trenchless industry? Contact journalist Gerald Lynch at gerald.lynch@primecreative.com.au
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