New Technology Replaces 80-Year-Old Sewer Line

A major upgrade of a sewer line in central New Plymouth will see some streets closed to traffic during construction.

700m of new sewerage will be laid from Huatoki Domain to Parsons St. The construction will require the temporary closure of a section of Huatoki St (near the Brois St intersection) and all of Parsons St – a key link between Govett Ave and Carrington St – for several weeks.

“We don’t have the exact dates for those closures yet but we will publicise them when we get closer to the date, so that everyone knows what is happening,” says Manager Water and Wastes Brent Manning.

“In the case of Parsons St the project requires us to dig a 10m deep hole on the roadway, and there isn’t any way we can have the road open to through traffic during that time. However, residents will still have access to their properties.”

The existing sewer was laid in 1930. It is one of the deepest sewers in the city and was laid within a specially constructed hand-dug tunnel.

“It’s incomprehensible now to think of men digging a tunnel by hand more than 10m below the ground, probably without any reinforcing on the walls – a very dangerous job,” says Mr Manning.

“Thankfully modern methods mean we can do essentially the same job in a much safer manner.

“We’re leaving the old pipe in the ground as it can’t be safely removed from that depth, and placing a new sewer in the tunnel using trenchless technology, which won’t put the workers at risk like they were in the 1930s.”

The 27-week project began construction this week, and will cost $1.66m. Once completed, the sewerage capacity for this area of the city will more than double.