A backburn used to fight the Green Wattle Creek bushfire was placed under the spotlight at the recent NSW Bushfire Inquiry.
The inquiry requested the NSW RFS provide details of independent investigations into backburning at the Green Wattle Creek, Currowan, Gospers Mountain and Grose Valley fires.
The NSW Rural Fire Service (RFS) website states that "a backburn involves burning a strip of land ahead of a main bushfire in order to remove fuel from between the advancing fire edge and the established control line".
Community members who provided feedback to the inquiry were divided on the effectiveness of backburning.
"Feedback from the community about backburning was polarised," the report stated.
"In some areas the feedback was that not enough backburning was done to protect properties, and in others that too much was done."
The Green Wattle Creek bushfire damaged or destroyed more than 30 homes in Wollondilly earlier this year.
More than 270 rural landholders were affected.
The inquiry was told that the eastern containment line of the Green Wattle Creek Fire was breached on December 19, 2019, "resulting in fire affecting the communities of Balmoral, Bargo and Buxton".
At the time of the backburn the fire had already burnt more than 120,000 hectares of land.
"There was community comment that the breach of the containment line had occurred as a result of efforts made to contain an earlier backburn which had been extended beyond its authorised termination point on December 14, 2019," the report said.
"The backburn in question was undertaken within the Buxton sector of the Dry Lakes Division located in the Nattai National Park to the west of the village of Buxton.
"The purpose of the backburn was to establish a containment line to prevent the fire extending to the east and avoid impact on a number of Southern Highland villages between Picton and Mittagong."
The NSW RFS investigation found that "local crews did not have appropriate clarity on how the existing containment line and the backburn would align, resulting in an inadvertent extension of the backburn".
"Once the error was identified, there was insufficient time to execute the fall back due to a diminished window of opportunity," the report stated.
"The NSW RFS reported that the outcome was highly regrettable and weighs heavily on the NSW RFS senior management and is personally devastating for those directly involved."
A NSW RFS spokesman told the Advertiser that it wasn't possible to determine if the loss of homes in the shire could have been prevented had the backburn been successful.
"Given the extreme fire behaviour and underlying drought, any backburn that is implemented in these conditions, is not a guaranteed success," he said.
"Therefore it is not possible to provide a definitive answer on the outcome or whether the burn would have been successful.
"During the 2019/20 fire season more than 1000 backburns were conducted on firegrounds across the state.
"Of this only four per cent were reported to have spotted outside of the proposed containment lines."
The spokesman said backburning was an essential firefighting method particularly when it is unsafe or impractical for firefighters to attack the fire directly.
"When large uncontrolled fires are burning across remote or large parts of the landscape backburning in strategic locations, when weather conditions are conducive, is often the only viable option for containing the fire," he said.
"It is not always possible, nor safe for firefighters to attack fire fronts.
"Introducing fire into or near a fire ground is an inherently risky undertaking.
"To minimise the potential adverse impact of back burning, careful planning and risk analysis is required.
"Despite appropriate planning, risk analysis and precautions, there are times when backburns breach containment lines and may cause damage or loss to property."
The spokesman said the organisation would endeavour to implement the inquiry's recommendations on backburning protocols.
"The NSW RFS is developing interim procedures this season ahead of full implementation, including system changes," he said.
The inquiry recommended that the NSW RFS accelerate its planned roll-out of Mobile Data Terminals (MDTs) for all NSW RFS fire fighting vehicles to ensure crews could access real-time information in an effort to mitigate future risks of backburns breaching containment lines.
The NSW RFS spokesman said that no firefighting vehicles in Wollondilly or the Southern Highlands were currently fitted with MDTs.
However he said the organisation would be implementing this recommendation as well.
"The NSW RFS is well advanced in preparing documents to put out to tender," he said.