The $115m pipeline lifeline

Greater Wellington Regional Council has approved a $115 million cross-harbour pipeline, between Wellington and the Hutt Valley.

The estimated cost of building an emergency water pipeline for Wellington shot up by $15 million in June.

The pipeline was one of two options considered to ensure the capital continued to have a fresh water supply should it be hit by a natural disaster.

The other, which was expected to cost between $60m and $70m, involved sourcing water using bores from the Waiwhetu Aquifer under Wellington Harbour, near Matiu/Somes Island.

The cost to date of the harbour bores investigation work is about $5.2m but the bores were found to be unsuitable.

The cost of the cross-harbour pipeline project is estimated to be about $115m, but it could change with further investigation and preliminary design works progress.

Currently the city’s water is piped from the Hutt Valley along State Highways 1 and 2, where it crosses earthquake faultlines many times.

If damaged, the pipes could take months to repair, leaving parts of the city without water for up to 100 days.

Regional council chairman Chris Laidlaw said the project had been ‘‘a bit of a journey’’.

Now that the options were considered the council had the confidence to start planning for the new pipeline, he said.