Ashley to Coldstream 66kV Upgrade

Ashley River

The Eastern area of the Waimakariri District has experienced significant growth due to residential and commercial development in the Pegasus and Ravenswood areas. This area is currently supplied by Transpower’s Ashley GXP, Kaiapoi GXP, and MainPower’s Southbrook Zone Substation, however, the 11 kV reticulation network is reaching its limitations and Capacity, Security of Supply, and Resilience risks are becoming apparent.

Several stages will be delivered over future financial years to address the current and future forecasted network constraints.

Those being:

  • Construct a conjoint 66kV and 11kV overhead line from Ashley and operate both circuits at 11kV
  • Construct the new Coldstream Zone substation.
  • Reconfigure the 11kV network to share the load across a number of zone substations.

Other projects

Ashley River

Ashley to Coldstream 66kV Upgrade

The Eastern area of the Waimakariri District has experienced significant growth due to residential and commercial development in the Pegasus…

Important notifications

Hot water load testing under way ahead of winter

Until mid‑April, we’re working closely with retailers to carry out hot water load testing as we prepare our network for the coming winter season.

These tests run for a couple of hours each day, Monday to Friday, with no testing taking place over weekends. Because each test window is relatively short, customers are unlikely to notice any changes to their hot water supply.

The purpose of this work is to help us better understand how much controllable load is available during the summer months. Gaining accurate insights now means we can model customer savings more effectively by reducing system load at peak times. It also helps us assess whether this load flexibility could assist Transpower in deferring an upcoming local transmission upgrade.

This testing is an important part of ensuring a resilient, efficient network that supports our community.

MainPower Trust elections

Voting is open for the 2026 MainPower Trust election.

Voting packs have been emailed or posted by Electionz.com to everyone who pays a power bill on the MainPower network. You need to have the unique ID provided to cast your vote.

If you haven’t received a voting pack, or can’t find it, you can get a replacement by contacting iro@electionz.com.  For full details of the candidates, visit mainpowertrust.co.nz/trustee-elections/

Make the most of this opportunity to have your say on the future of MainPower – and your community.

Voting closes midday Friday 6 March 2026. 

Privacy Policy

Is your outage not listed?

Troubleshoot your outage
Treat all lines as live during the outage period; power may be restored at any time. If you require further information, please call MainPower’s 24-hour faults line. To report an emergency, call 111.

Outage notifications

Hot water load testing under way ahead of winter

Until mid‑April, we’re working closely with retailers to carry out hot water load testing as we prepare our network for the coming winter season.

These tests run for a couple of hours each day, Monday to Friday, with no testing taking place over weekends. Because each test window is relatively short, customers are unlikely to notice any changes to their hot water supply.

The purpose of this work is to help us better understand how much controllable load is available during the summer months. Gaining accurate insights now means we can model customer savings more effectively by reducing system load at peak times. It also helps us assess whether this load flexibility could assist Transpower in deferring an upcoming local transmission upgrade.

This testing is an important part of ensuring a resilient, efficient network that supports our community.

MainPower Trust elections

Voting is open for the 2026 MainPower Trust election.

Voting packs have been emailed or posted by Electionz.com to everyone who pays a power bill on the MainPower network. You need to have the unique ID provided to cast your vote.

If you haven’t received a voting pack, or can’t find it, you can get a replacement by contacting iro@electionz.com.  For full details of the candidates, visit mainpowertrust.co.nz/trustee-elections/

Make the most of this opportunity to have your say on the future of MainPower – and your community.

Voting closes midday Friday 6 March 2026. 

Privacy Policy

Is your outage not listed?

Troubleshoot your outage
Treat all lines as live during the outage period; power may be restored at any time. If you require further information, please call MainPower’s 24-hour faults line. To report an emergency, call 111.

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