Western Power has admitted it failed to safely maintain a wooden power pole that was reported as having wood rot and almost six months later caused a bushfire in Two Rocks.
The fire in January 2009 tore through Yanchep National Park and destroyed a big swath of plantation timber.
It was sparked when wires on the 22,000-volt Wanneroo North power line clashed repeatedly. The fire burnt 7500ha of land and 2500ha of pine plantation, which reportedly represents about 250,000 tonnes or one year's supply of timber.
Western Power faces a fine of up to $20,000 when the State-owned utility is sentenced in Perth Magistrate's Court today after yesterday pleading guilty to failing to safely maintain the power pole at Breakwater Drive, Two Rocks.
The utility has also pleaded guilty to a separate charge of not maintaining service apparatus in a safe and fit condition for supplying electricity over an incident in 2010.
A meter-box cover at a Bentley property was not properly installed after work on power poles as part of an underground project. The offence carries a maximum $250,000 fine.
Reading the facts about the 2009 Two Rocks fire, prosecutor Tim Russell, representing the Office of Energy Safety, told the court the wooden poles on Breakwater Drive were inspected in July 2008.
He said an inspector noted the top of a pole had signs of top split and wood rot and assigned it as a priority two, which meant it should have been fixed within three months.
But a computer glitch led to the inspector's report being directed to the wrong area within Western Power and the pole was not fixed. Mr Russell said Western Power had failed to ensure the pole was properly maintained and "knew and accepted" that it needed to be replaced.
He said Western Power's breach of the electricity supply standards and system safety regulations had resulted in a serious bushfire, which caused significant property damage.
Western Power's lawyer Richard Barsden told the court the utility had pleaded guilty at the first opportunity after negotiations with the prosecution. A Western Power spokeswoman said it regretted the events and accepted responsibility and was seeking to ensure similar incidents were not repeated.
Western Power had since improved work practices, she said, "including how we manage contractors, altered training programs and changed accreditation systems to reduce the risk of these types of events happening again".
The Office of Energy Safety did not put a value on the cost of the land or pine plantations which were destroyed in the fire.