Tunnel halts $7m waterfront upgrade

A $7 million upgrade of Quay St has come to an abrupt halt after power lines company Vector discovered it may need to dig up new footpaths, native trees and landscaping for a power tunnel.

Vector said it became aware of the problem only after Auckland City Council was well down the track in transforming Quay St into an attractive, people-friendly space on the waterfront.

When the council approached Vector last year to see if it had any works planned that could be done at the same time, Vector decided to build a tunnel on the southern, city side of Quay St, a spokeswoman said.

"We have a formal partnership with council and constantly compare work plans with them and other utilities to ensure we are carrying out projects in the same area at the same time," she said.

"We looked at our works schedule and actually brought the replacement of our Quay St tunnel forward by two years."

The $7 million upgrade, which involves new footpaths, sprucing up the entrance to the Viaduct Harbour and laying bluestone paving in front of the historic Ferry Building, has been taking place on the northern, waterfront side of Quay St since August. It was due for completion in March.

The spokeswoman said the plan to upgrade the existing tunnel had become unfeasible and it had to look at other options, including a new tunnel on the waterfront side of Quay St.

"By this time the council had already contracted out stages one and two of the upgrade. Stage three of the upgrade has, however, been put on hold until our works have been completed," the spokeswoman said.

Vector is giving little away about the tunnel project to upgrade and provide additional power capacity between its Tinley St substation and the inner city until it has a final option "in the next few weeks".

Auckland City's manager of utility service, Des Hughes, said Vector had planned a tunnel on top of its existing tunnel, which was up to 70 years old, but discovered it was not feasible.

Mr Hughes said Vector needed to dig a 6-7m deep trench down the northern side of Quay St to take a 2.7m-diameter pipe to form a new tunnel.

It was a complex job that would involve moving stormwater and telecommunication services. The work would take about 12 months and might start in October or at the end of summer.