Robot and other technology called in for sewer work in Whangārei

Contractor Rasool Mohsin inspects the inside of a sewer pipe using a camera he can control which is attached to the end of a cord. Photo/John Stone

A robot will be called in to help make sewer upgrades in Hikurangi faster and more efficient.

The $1.8 million renewal of the town's sewer network aims to put an end to decades of weather-related sewer problems that have affected the area.

It's one of the biggest improvements to the town in recent times but will be all but invisible as it happens mainly below ground.

The first stage has been completed and work is starting on the second stage.

Whangārei District Council waste and drainage engineer Casper Kandori said in the upcoming work all 9km of sewers in the settlement would be inspected using CCTV to confirm the condition of the pipes.

About 2km of pipe would be relined and 1.2km would be replaced.

"The company completing the work will also use new technology, including 'pipe bursting' technology that replaces existing pipes without any digging. Other new technology will allow pipes to be re-lined without digging, and some connections to properties will be cut using a robot. This will minimise disruption and speed up installation."

Kandori said the council's maintenance contractors have used robots prior to this job, but it was "quite exciting" to use it on a big project.

He said the robot had also been used on other projects around the country.

Hikurangi's sewer system is one of the oldest in the district. It is also low-lying which has seen ground and floodwater flowing into sewer pipes and causing overflows and loss of service whenever it rains heavily.

Stage one involved upgrading the sewer mains to ensure they will be big enough to take all the sewage to the treatment plant once the network is improved. This part of the job involved two new pump stations and pressure mains between the rugby clubrooms and the treatment plant at Jordan Valley Rd.

Kandori said that job has been completed and work has begun on state two - renewing and rehabilitating the entire local network of pipes.

"This is the final part of this wastewater network upgrade for Hikurangi. We did stage one followed by property inspections to check gully traps and downpipes last year. Some of the faults have already been notified and fixed."

"Renewing the pipe work in this stage will reduce the amount of stormwater and groundwater that enters the system, reducing overflows in the area. This had been a menace for properties at Union St that, for a while, used portaloos to avoid flooding the sewer system. Their situation has been sorted out and residents confirm there has been no more flooding and that the new system is working well."

He said residents will be notified in writing and many will be visited to discuss access arrangements and project details.