There has been renewed criticism of the fire danger on DOC land, from a man who spent his career fighting rural fires.
Fire damage at Lake Ōhau village. Photo: RNZ / Anan Zaki
Murray Dudfield was National Rural Fire Officer for 24 years before retiring.
He said more fires like the Lake Ōhau blaze were inevitable because two-metre-high tussock growing on DOC land could be engulfed in flames with just a few sparks.
This would endanger neighbouring property in many parts of the South Island, he said.
The Lake Ōhau blaze destroyed 48 buildings and burnt through 5040 hectares of land.
Local farmers said it was made worse when flames raged through thick vegetation on DOC land, while their own farms were grazed down to ground level and provided very little fuel to burn.
Murray Dudfield said he tried for years to get DOC to reduce the growth of flammable vegetation, but nothing happened.
As a result, a lot of DOC land became so overgrown with vegetation that it became an obvious fire danger.
He cited other fires besides the Lake Ōhau blaze, including a big one earlier near Middlemarch last year.
"That was a 5000 hectare tussock fire that burnt a lot of DOC lands," he said.
"Those lands were retired under land tenure review.... and vegetation had been allowed to build up.'
Dudfield said many of the tussocks were two metres tall and would burn after any sort of ignition.
"It's not a case of if, it's a case of when, those lands burn."
Earlier, farmers said selective grazing of this land could keep flammable vegetation levels down.
There could also be pre-emptive controlled burn-offs of some areas to bring safety to other areas.
In response, DOC said its high country land was home to many species - such as butterflies and lizards - and it had to be protected.
DOC also said it wasn't true that grazed land was immune to fires.
In a statement, DOC said 'fire proofing' of public conservation land was largely unachievable.
And while reducing vegetation could reduce fire intensity, it did go to the root cause of reducing the source of fires.
DOC added its policy allowed in principle for controlled burn-offs of dangerous areas in limited circumstances, but further research was needed.
Meanwhile the insurance industry has said it wanted better fire controls on land with flammable plant growth, including land managed by DOC.
It wanted preventive measures in place because it had to pay up when flames raced through thick undergrowth and burnt down an insured house or farm building.
Tim Grafton of the Insurance Council said while the cause of the Lake Ōhau blaze was still being sought, he insisted landscapes had to be managed safely.
"It's really important that as far as possible, those who own or manage land, especially in rural areas, ensure that any flammable vegetation is kept down to a minimal level to avoid the spread of a catastrophic fire."
Grafton was reluctant to say whether failures to put fire controls on vegetation could push up the price of insurance or reduce its availability.
He said it could, but there were many other factors going in to setting insurance premiums.
