Transpower outlines plan to repair flood-damaged transmission line

20 December 2019

Transpower has confirmed it will take some months to fully repair the damage caused to its assets recently when the Rangitata River flooded.

Nine of Transpower’s towers were damaged, however there was no loss of electricity to the region, with supply maintained to Christchurch and the upper South Island via other transmission circuits.

Transpower today announced that temporary repairs will be made immediately to shore up the security of supply for the region, which are expected to be completed by April. At the same time work on a permanent solution is underway.

In its role as the national electricity grid owner and system operator, Transpower held an industry teleconference this morning regarding the temporary and permanent solutions identified by its engineers.

Mark Ryall, GM Grid Delivery, said the temporary repair plans included installing concrete poles into the river bed and ground alongside the existing line where towers were damaged.

“Work on the design for the temporary line has begun. We expect to be finished by April at the latest.”

“We are also working on a permanent solution, which we are aiming to complete by August.”

Transpower has also reviewed the region’s forecast electricity demand and generation through the summer. This is to determine if any action needs to be taken to ensure supply can meet demand, as demand increases.

John Clarke, GM of Operations, said while the remaining three circuits can securely supply the upper South Island demand for now, from mid-January electricity demand typically increases with the increased use of irrigators in the region.

“We have asked our upper South Island distirbutors to help us to manage their peak demand over this period.

“In addition, to manage the impact should another of the remaining three circuits trip, contingency measures have been identified that would reconfigure the 220kV upper South Island network.

“We would only introduce these measures if we lost another circuit supplying the region. In this case, we would reconfigure supply so that the remaining two circuits supplied Christchurch and North Canterbury/Nelson separately to one another.”

“We’d like to thank the industry for their support and assistance as we repair the transmission line,” Mr Clarke said.

Transpower is confident the contingency measures it has put in place, and the repair plan it has developed, provides the best possible solution for the region as work gets underway. 

For further information, please contact:   

Patrick O’Meara Senior Corporate Communications Advisor on 04 590 8626 or 027 491 6341