The WorkSafe audit, which was released to the Otago Daily Times under the Official Information Act, also found inadequate testing of poles meant some unsafe poles may not have been tagged.
Among "unsafe" power poles it found were ones that were split, ragged and bending. The audit resulted in WorkSafe issuing a list of instructions to the Dunedin City Council-owned lines company for how it should carry out its fast-track pole replacement programme in a way which ensures worker and public safety.
Aurora Energy general manager, operations and risk, John Campbell said it welcomed the opportunity to improve its network and had addressed most of the concerns raised in the audit.
Worksafe said it carried out the audit — written by Energy Safety technical officer Roy Butler — in response to "media attention regarding concerns of the unsafe condition of power poles on the Aurora network".
What it found backed up many of the concerns raised by former Delta workers and members of the public.
"Energy Safety observed a large number of network assets of concern and in need of replacement and maintenance," Mr Butler said.
It carried out pole inspections in a number of Dunedin locations, including in North Rd, near Dunedin North Intermediate and Sacred Heart school.
"Unsafe poles observed during the inspection included: split and ragged tops, decay, delaminating and cracks, plant life and algae on poles and cross arms, leaning and bending poles, rusting and spalling, ground-erosion.
"Of particular concern was that many red-tagged poles were next to each other.
"Assuming the most severe condition of the presently red tagged poles, a failure of one of these poles would have an adverse effect on the adjacent red tagged poles potentially accumulating in a compounding incident."
The audit also called attention to the way poles were tested.
"An inadequate and inconsistent testing method has meant that some unsafe poles may have been left untagged and some possibly less severe poles have been red tagged."
Energy Safety also visited four substations at random and found they were in various degrees of condition from recently refurbished to "a partially redundant switchyard of some concern".
Mr Campbell said since receiving the audit report in March it had reinspected each site and was "very close" to completing all remedial work required.
Extreme weather had delayed work on some issues raised, which were now expected to be addressed this month.
"The item related to the Outram zone substation had already been identified and the project to bring the configuration up to modern design standards is under way."
As of yesterday it had rectified 20 of the 27 items identified, including four pole replacements, six minor repairs and 10 pole reinspections, where the poles were retested and assessed as serviceable.Three issues raised were about assets that did not belong to Aurora.
A WorkSafe spokesman said it would continue to monitor the performance of Aurora’s pole replacement programme against regular progress reports.
Asked if WorkSafe could launch a prosecution against Aurora over its failing he said: "WorkSafe continues to engage with Aurora to ensure network and safety improvements."
"However, enforcement tools such as prosecution remain options if they are required."
WorkSafe was "satisfied" with Aurora’s approach to improving its network and the progress to date.
