A eight-month technical review of the lines company's network by WSP found while most of the network posed little risk, there were some exceptions.
WSP was commissioned by Aurora and the Commerce Commission to carry out the review of the lines company's network in Dunedin, Central Otago and Queenstown Lakes.
An executive summary of the review was released yesterday but the full report will not be available until next week.
The review identifies 35 incidents between 2015 and 2018 where a conductor fell to the ground and then remained live because protection systems failed.
No-one was injured during the incidents.
Failures included a fuse which did not react to a fault and protection delays which did not detect the issues.
]WSP manager Michael Van Doornik said the review found most of Aurora's assets posed a low risk to public safety, reliability of supply and the environment, but some work was still needed on the network's most high risk assets.
Overall, most of the risks identified were no greater than what WSP had observed in other networks, but there were some exceptions.
As well as relying on data provided by Aurora, WSP conducted its own review of some of the lines company's assets, including inspecting about 800 poles and cross arms, Mr Van Doornik said.
The review cost about $400,000.
Aurora Energy chief executive Richard Fletcher said the review highlighted specific areas were the company needed to take steps to address the existing and emerging risks.
Based on the review, the company planned to develop an accelerated plan for the replacement of high risk protection relays, enhance its reporting of risk and report on the network's resiliency, and achieve greater resilience, Dr Fletcher said.
Overall the network was safe, though the condition of its protection systems, poles and cross arms carried a higher risk - but Aurora was working through the renewal backlog to minimise risk, he said.
