Under our deed with our majority shareholder, the Auckland Energy Consumer Trust (AECT), we have committed to spend $13.2 million a year on undergrounding the remaining overhead power lines in urban parts of the former Auckland, Manukau and Papakura areas.

Selecting areas to underground

A significant part of the programme involved undergrounding areas in large blocks. We aim to carry out one or two major projects a year while also conducting a number of smaller undergrounding projects at the same time. We identify undergrounding opportunities from other capital projects planned for the year and, wherever possible, we 'piggy-back' on these projects to underground areas, which would not normally have priority.

We use a number of criteria to select areas for undergrounding, including:

• the condition of the lines and equipment in the area
• their performance history (capacity and faults)
• the number of customers who will benefit
• the level of other utility works planned for each area.

Vector’s deed with the AECT does not extend to our network in the former North Shore, Waitakere and Rodney areas. The AECT was formed as part of reforms to the electricity industry in 1993 representing electricity consumers in the area that was served by the Auckland Electric Power Board (AEPB). At the time the Deed was formed Vector did not own the North Shore, Waitakere and Rodney network.

'Dig once' policy

A key part of our undergrounding programme involves our 'dig once' policy - where we aimed to coordinate works with  Council and other utilities so essential services were undergrounded together - or other complementary works are carried out - in the same place, at the same time to limit the amount of disruption.

This cooperative approach aims to do a 'once-through' total revitalisation of an area while undergrounding work was being carried out. This means the final areas selected not only benefit from underground services, but may also benefit from new street lighting, upgraded pavements, new trees and streetscaping or curb improvements at the same time.

The benefits of undergrounding

Undergrounding improves the neighbourhood skyline and removes the need to trim trees around power lines, while streetscape improvements improve the aesthetics. A wide range of factors can cause disruption to an overhead power supply - including bird strikes, bad weather, trees striking the lines or cars hitting power poles. By undergrounding the power supply, such interruptions can be almost eliminated.

Customer communications

A comprehensive communications programme has been developed to ensure all those interested or who will benefit from undergrounding have been kept well informed.