Redclyffe substation rebuild

Last updated: 09 Dec 2025

What are we doing?

On February 14, 2023, Cyclone Gabrielle caused widespread damage across Hawke’s Bay, destroying hundreds of homes and causing power outages. Most of Hawke’s Bay’s electricity is provided via interconnection at our Redclyffe grid exit point. Redclyffe and Whirinaki substations were both flooded and the flood waters at Redclyffe triggered power outages at Redclyffe, Fernhill, Tuai and Whakatu.

This natural disaster caused the greatest loss of power supply the region has experienced.

Transpower and Unison, the local electricity distributor, have reviewed the need for resilient infrastructure so that people and business in Hawke’s Bay can have a greater level of assurance that another major flood event will not cause a similar power outage.

Our focus is now on rebuilding the substation with increased resiliency.

We proposed this investment to the Commerce Commission in June 2025. We have since received confirmation from the Commission in December 2025 that it supports our planned investment, and you can read our media release here.

All our application documents to the Commerce Commission can be found here.

Following the Commission's consultation on this investment, we expect work to start on the rebuild in October 2026.

Timeline and updates

What has happened so far?

The 110 kV switchyard has had interim upgrades performed to make the equipment there more resilient to flooding.
We have installed a new temporary control room above the flood level to ensure that the most critical control equipment is flood resilient.
A new 220 kV/110 kV interconnecting transformer has been installed. This additional larger capacity transformer is able to supply more electricity into the area, and will meet 1 in 450-year flood protection standards.
The Commerce Commission has approved our planned investment and will now consult on it. All things going well, we expect work to begin in October 2026 and be completed by December 2027, with no expected impact to local electricity supply.

Consultation on Major Capex Proposal

Transpower has concluded consultation on delivering another level of resilience at Redclyffe Substation in the Hawke’s Bay, which was badly damaged two years ago during Cyclone Gabrielle. This consultation ran from 11 February through to 11 March 2025. Here is the document summarising the submissions we received.

Please see the submissions we received from the following organisations -

These were the consultation documents -