Omakau Zone Substation Upgrade

This project will require a new substation at a different location, as the current substation on the Ida Valley-Omakau Road is in a flood risk area with no room for expansion. The upgraded substation is being built on a new site, next to the Omakau stockyards on Lauder-Omakau Road, State Highway 85. The current substation will be decommissioned and removed once the new substation is up and running, apart from the surrounding power poles.

What are the benefits?

The new zone substation will be fully automated, and provide more options during planned and unplanned outages. The substation also has a mobile parking bay, which will allow us to bring in a temporary transformer to carry out maintenance work required on the substation without any disruption to customers.

The new diesel generator was installed at the new substation site in May 2022, and was commissioned in November 2022. It has already been used in recent planned outages to supply customers with power while we undertook work on the 33 kV network in December 2022.

The generator will also provide emergency power supply for most of the community if a major fault occurs on the line from Alexandra, or on the Omakau substation transformer, which will reduce the customer impact.

We have additional projects coming up that will also help to improve the quality of supply, including:

Lauder Flat back-up supply

During 2023/24 we will upgrade the 11 kV conductor between Omakau and Lauder Flat and install a voltage regulator. This work will improve the performance of the network in two ways. Firstly, the new conductor and associated fittings will address age-related defects and thereby reduce the fault rate and the number of outages. Secondly, the upgraded conductor with the voltage regulator will increase the back-up support between the Omakau and Lauder Flat substations.

Reclosers (automatic and remotely operable switches)

The new substation location creates an opportunity to install new reclosers and to relocate existing reclosers on the overhead line network. This will reduce the number of customers impacted if a fault occurs and speed up supply restoration.

Chesterman Road Voltage Regulator

This project will resolve low voltage issues occurring during the irrigation period from Chesterman Road towards Devonshire Road. The plan is to complete the project by November 2022, before the next summer period occurs.

Investigate the feasibility of an improved Alexandra to Omakau link

This will provide better back-up from Alexandra into the Chatto Creek area.

Investigate options for a new line to Ida Valley

The valley is currently supplied by a single line from Omakau and therefore a fault on the line causes an outage to all of Ida Valley until the repair work can be completed. We are investigating the feasibility of a second line into the area, enabling the network to be split with a back-up from each line.

We also have ongoing power pole, crossarm, and line replacements planned.