"The decision to lay charges brings to a head a long and complex legal investigation and demonstrates we are prepared to hold businesses to account," Energy Safe Victoria director Paul Fearon said.

"Although many have demanded that ESV take this action earlier, these matters are not trivial and the burden of proof is high," he said

Powercor will face court over two incidents:

The charges are for breaches of the Electricity Safety Act general duties under Section 98.

They relate to Powercor's failure to operate and maintain its network to minimise as far as practicable:

Powercor faces two counts of each charge, one for each fire.

The maximum penalty for each offence is $250,000 - so if Powercor was found guilty, the most it could be fined would be $1.5 million.

The charges have been filed at the Warrnambool Magistrates Court with a first mention set down for January 20.

Mr Fearon said there had been pressure from the farming communities around the fire areas to lay charges earlier.

"While we absolutely understand the loss and the damage and expectations of the local communities that action must be taken, the fact is we have to do it in accordance with the law," he said.

"We are attempting to prove to a criminal standard what conduct of general duty is expected. It's not a trivial or easy matter to do."

Mr Fearon said this was the first case of its type against an electricity distributor.

"For that reason it is a very important test case," he said.

"It will be a point for what conduct is necessary to meet the standard and general duty, which is minimising the risks as far as practicable.

"If anything it demonstrates that we are prepared to take action and we have the capability to do it," he said.

The announcement of charges comes after the Supreme Court class action involving Terang/Cobden bushfire victims started on Monday in Warrnambool this week.

Barrister Tim Tobin, for lead plaintiff Anthony Lenehan, claimed in his opening address Powercor failed to look at its own data which could have prevented the devastating fire.

He said Powercor had straightened an anchor pole in 2007 to ensure the conductors were separated but the same pole in a clay table drain had shifted, reducing the gap between conductors.

Mr Tobin said clashing conductors at pole No. 3 near the Terang electrical substation led to molten metal falling to the ground, sparking the blaze.

He said the conductors should have been 900mm apart but were only 210mm apart, a "grossly insufficient clearance" and if Powercor complied with its own standard the fire would never have started.

The fire burnt 18 kilometres in a south-easterly direction, torching 4000 hectares, 90 properties, homes, sheds, fences and livestock.

Powercor did not dispute the cause of the fire.

Powercor barrister Tim Margetts, QC, said there was no argument that Powercor had a duty of care but the dispute was whether plaintiffs had the right to claim damages.

He agreed Powercor had an obligation to inspect and maintain its assets.

"In this trial we say that from a Powercor perspective, Powercor has discharged that duty," he said.

Mr Margetts said the question was whether Powercor had discharged its duty and exercised reasonable care.

He said there were risks in the supply of electricity that could not be completely eliminated and not all potential risks could be prevented or all risk removed.

Four main St Patrick's Day fires swept through Victoria's south-west on March 17 last year - at Gazette, Camperdown/Gnotuk, Terang/Cobden and The Sisters/Garvoc.

Read more:

ESV completed a technical report which found that of the six fires that ignited that day from electrical assets, two should be pursued for legal investigation.

These two fires - Terang/Cobden and The Sisters/Garvoc - are now the subject of the charges brought against Powercor.

A further report into the safety of wooden power poles in the south west was released July 29.

The report found there was no immediate systematic issue with Powercor's inspection and maintenance regime.

A further report will be released in December following a review of the longer term sustainability of Powercor's regime.

"This action will provide an important test for the existing statutory safety scheme and future actions of this kind," Mr Fearon said.

A Powercor spokeswoman said: "We acknowledge ESV's action and will not be providing comments while legal proceedings are underway."

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