A bush fire that has destroyed 300 hectares on the outskirts of Port Macquarie is under investigation.
Firefighters from Fire and Rescue NSW and NSW Rural Fire Service (RFS) were called to the blaze on Lindfield Park Road on July 18.
Fire and Rescue Port Macquarie Inspector Bradley Harrison said the cause of the fire, which has now burned between more than 260 hectares over the weekend, is being investigated.
"The fire is just smoldering now in peat and swamp. This morning I officially handed over the operations to the Rural Fire Service," said Inspector Harrison.
"RFS are continuing to patrol the fire."
A smoke warning remains for the Oxley Highway between the Pacific Highway and Wrights Road.
Motorists are advised that smoke is affecting visibility so they should reduce speed and exercise caution.
The Oxley Highway was closed in both directions earlier this week due to heavy smoke in the area contributing to traffic accidents.
"Our biggest issue is the smoke, particularly at night when it covers the Oxley Highway," said Inspector Harrison.
"People have got to be aware that Roads and Maritime Services (RMS) may reduce the speed or cut it down to one lane because of the risk of heavy smoke. We're hoping that will dissipate in the next few days."
Large amounts of smoke is being generated by paperbark and tea trees burning in swampy areas, with temperature inversion at night creating hazardous smoke conditions. Melaleuca forest is highly flammable and tea tree oil burns quickly, producing lots of smoke.
Sancrox-Thrumster Rural Fire Service (RFS) explained temperature inversion as warm air capping cooler air which traps smoke close to the ground at night and in the early morning. The trapped smoke generally begins to lift after the sun rises.
Drones were used to assist operations, however aerial firefighting units were held in reserve because no property was under threat, according to Inspector Harrison.
"The reality is that this (area) hasn't burnt for almost 30 years, there is quite a lot of fuel load," he said.
"There were no structures or properties in danger. At this stage there has been no determination for use of air assets (to extinguish the blaze).
"We had our aviation officer up there yesterday (Sunday, July 21), he has operated drones to give accurate readings of where the fire has burnt or not.
"This gave us a good picture of where the fire has been and where it potentially can go.
"It's been a few years since we have had a fire of this magnitude. The last major one was at Kempsey and for Port Macquarie, this is the largest commitment we have had for a bush fire in some period of time."
North Coast Public Health Unit is advising people to consider their health while smoke is affecting the area and avoid prolonged or strenuous outdoor activities when smoke levels are high.
To stay up to date with the situation, please download the Fires Near Me App, or visit www.rfs.nsw.gov.au
Remember, now is the time to start thinking about preparing your property for the summer ahead. Go to www.myfireplan.com.au
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