In December last year The Sisters dairy farmer Jill Porter independently had power poles on and near her property tested after she found a see-through pole.

That pole was just metres from rotten pole No. 4 on the Sparrow Spur line which snapped in high winds on St Patrick's Day last year, sparking The Sisters/Garvoc blaze.

The independent testing raised questions about the structural integrity of the poles, which led to eight poles being removed at The Sisters by electricity distributor Powercor.

Powercor then committed to almost doubling the poles it replaces annually to 2200 in its 577,800-pole system.

In 2017 the company replaced 1152 poles - a fraction of one per cent.

Powercor also undertook an audit of almost 20,000 poles in the south-west.

Energy Safe Victoria then conducted a review of the audit and in May released an interim report saying the Powercor system was "fit for purpose".

On Monday ESV released its final report on the immediate risks impacting the safety of power poles in the south west.

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The report came about after significant community concern following the St Patrick's Day bushfires.

Started by electricity assets, the fires destroyed a significant amount of property and livestock leaving property owners fearful that further bushfires may occur.

Several community members, in particular Mrs Porter, questioned the adequacy of Powercor's maintenance regime, particularly its inspection and pole replacement practices.

After the interim report release several issues were raised around the adequacy of the regulatory regime, ESV's investigations of the St Patrick's Day fires and its response.

"The submissions demonstrated a need to build trust and understanding of ESV's role," Director of Energy Safety Paul Fearon said.

"Clearly we need to engage more effectively with the community and I look forward to working with government to improve how we do this.

"ESV has commenced the next phase of its investigation which will examine issues affecting the long term sustainability of power pole maintenance in the south-west."

Member for Polwarth Richard Riordan said the report was dynamite.

He said there were five million poles nationwide and the report suggested at least 1.3 per cent needed to be replaced annually - 65,000.

"The bulk of those poles are in Victoria," he said.

Mr Riordan said the number of poles available from suppliers was between just 3000 and 4000.

"There are two massive problems. The poles that need to be replaced and the poles available," he said.

"These issues were raised by Jill Porter, have been highlighted by myself and others and now government authorities are starting to realise the size of the problems they have been wilfully blind to.

"ESV is now saying its starting an investigation phase. For heaven's sake."

Mr Riordan said more than half of Powercor's 577,800 poles were more than 50 years old and poles had a life expectancy of 60 years.

He said that on any estimate Powercor needed to be replacing more than five times the number of poles it currently was to help make the infrastructure system sustainable.

"It takes 35 to 40 years to grow these poles. What's going to happen is that the system is at risk of collapsing while we're waiting for them to grow."

"I'm no rocket scientist but this is basic mathematics that everyone can understand."

Mr Riordan has previously claimed a Powercor official told him the company should be replacing 14,000 a year.

An industry source said ESV's response to submissions provided little comfort and confirmed the regulator was out of its depth technically.

"They operate a process-based regulatory regime, and say they will only intervene 'in response to emergency situations or an imminently dangerous or a foreseeable safety incident occurring'.

"After The Sisters/Garvoc fire, Powercor re-tested the surrounding poles, and assessed them as `fit for purpose'.

"But, independent testing engaged by Mrs Porter showed that pole No. 11 was likely to fail. Indeed, Pole 11 did fail subsequent destructive testing.

"So, how can Powercor's testing be fit for purpose? And how can Energy Safe Victoria help make Victorians safer?"

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