Two years ago this past weekend, a ferocious bushfire erupted near the edge of the Blue Mountains town of Winmalee, destroying almost 200 houses before many firefighters arrived or absent residents could return to protect their homes.

As another long fire season unfolds, many communities will again be casting an eye at surrounding bushland and asking whether authorities have done enough to reduce the fire risk, including by prescribed or hazard-reduction burning to reduce fuel loads.

In the wake of the 2009 Black Saturday bushfires, Victoria introduced a goal of burning of 5 per cent of public lands each year, a goal that Tasmania also aims for. NSW doesn't have such a goal but authorities are routinely under community pressure to conduct more extensive hazard-reduction fires.

New research, however, indicates such controlled burning is likely to have "leverage" in reducing the area burnt by later fires in only four of 30 regions examined across the ACT, NSW, Victoria and South Australia.