Lawyers for the Royal Commission into Black Saturday have urged the commissioners to recommend sweeping changes to Victoria’s electricity industry.

Senior counsel assisting the inquiry, Jack Rush QC, told the commissioners five of the eleven major fires on Black Saturday were caused by powerline failures.

He said Victoria’s powerlines were old and proposed the commissioners recommend the single wire transmission lines that serve Victoria’s regional areas be replaced over ten years, perhaps with underground lines.

Mr Rush also proposed a return to more frequent inspection of power lines.

He said the current regulatory regime was “fundamentally weak” and recommended it be reformed to give the regulator more muscle.

Mr Rush recognised the enormity of the task and the massive cost, but said unless changes were made, Victoria would continue to experience the types of losses seen on Black Saturday.

Costly

The electricity company whose powerline has been blamed for starting one of the deadliest fire says it would cost up to $7.5 billion to place all transmission lines underground.

The fire that hit towns like Kinglake has been blamed on a snapped SP AusNet powerline in Kilmore.

Lawyers for SP AusNet have said that would cost between $6.5 billion and $7.5 billion for its network alone.

The power company says the cost would be borne by the Victorian Government and consumers, with an annual price rise of 20 per cent over the next two decades.

SP AusNet urged a more targeted use of undergrounding, depending on things like bushfire risk and terrain.

The lawyer also questioned the justification for replacing powerlines based on age rather than condition.