The Rural Fire Service (RFS) incident controller who decided to proceed with a back-burn on the South Coast the night before New Year's Eve 2019 has told the New South Wales coroner the strategy was necessary to consolidate an incomplete containment line.
Mark Williams was called on Tuesday to give evidence at the inquest, which is examining back-burning operations during the 2019/20 bushfire season.
Mr Williams was the district manager for the Shoalhaven RFS and was appointed incident controller for the Currowan fire, which it was started by a lightning strike in November 2019.
Within a month the blaze had merged with four other fires to cover about 315,000 hectares and eventually destroyed hundreds of homes in the Shoalhaven and Wingecarribee local government areas.
The fire also resulted in the deaths of three men who had been protecting their homes.
Mr Williams told the court that at its peak the fire had a perimeter of 500 kilometres, all of which was under his purview.
He said by early December it had become clear that it would be a difficult fire to control or contain.
"Certainly the fire behaviour was extreme in comparison to the weather conditions we were having at the time," Mr Williams said.
"The rates of spread were high … it was burning through thick vegetation … which made access [difficult] and any sort of firefighting [had to be] defensive."
Inaction 'not an option'
The court was told Mr Williams instructed crews to proceed with a back-burn between midnight and 2:00am on the 30th of December, but firefighters had to be withdrawn because the conditions became unsafe for the work to continue.
"Was that something you factored into your decision making … the possibility that you might continue the strategic back-burn but then have to withdraw firefighters because of safety concerns?" counsel assisting Donna Ward SC asked.
"We knew we didn't have the resources that we knew we would normally allocate to an event such as doing that, but the need overrode those sorts of [circumstances]," he said.
Ms Ward said one resident had provided a statement to the inquest claiming they felt the introduction of more fire into an extremely dry landscape was "very dangerous unless there were enough resources to control the back-burn".
But Mr Williams said the strategy adopted had been better than doing nothing and that the decision had been with knowledge of the forecast weather conditions.
"To sit back and not close those gates was not an option," he said.
Mr Williams told court the eastern containment strategy had been developed in a bid to stop the fire's spread across the Princes Highway towards more densely populated coastal communities.
Catastrophic conditions
Mr Williams said the 108km containment line had been established using a combination of back-burning and heavy machinery, but it was incomplete the day before the catastrophic fire conditions forecast for December 31.
"Certainly we knew that the weather conditions were deteriorating," he said.
"It did push us to ensure that we had that back-burning done well and truly before that weather system came in … to shut the gates."
Mr Williams explained that the incomplete sections of the containment line only provided a fuel break of between four and six metres and did not have enough "depth" to provide "reliable protection".
He said not proceeding with the burn could have allowed the fire to spread "relatively unimpeded".
The court heard in the hours after the back-burn was lit, the fire spotted over the containment line and eventually destroyed dozens of homes at Conjola Park on New Year's Eve.
By that point Mr Williams was no longer in charge of managing the fire because he had been redeployed at about 6am on December 31 to assist efforts further south, where the Clyde Mountain Fire was threatening properties and lives in the Moruya area.
"At the time you were directing people on the 30th of December, had you expected to be the [Currowan] incident controller on the ground during the day on the 31st?" Ms Ward asked.
"I did," Mr Williams replied.
