Wildlife authorities say koalas are being found in suburban Sydney backyards after being driven from their homes by bushfires and land clearing.

National Parks Association ecologist Dr Grainne Cleary says the the association has received "a few" reports of koalas in western Sydney.

"We're out here looking at one right now," she said from a Campbelltown backyard where a male had taken up residence. "We saw a mum and baby out here yesterday."

The NSW National Parks Association kicked off the first koala census since 2006 yesterday with the assistance of 600 volunteer "citizen scientists".

Cleary says the koalas may be being forced into urban areas by the destruction of their usual habitats.

It's estimated that NSW has between 26,000 and 32,000 koalas.

However, Cleary says she expects koala numbers in some areas to have fallen after this year's hot weather and bushfires.

This year's 10-day koala count is the first of what the National Parks Association hopes will be an annual study helping scientists track the impacts of climate change, people and weather.

More than three weeks after bushfires tore through the Blue Mountains, the region's mayor says not a single destroyed property has been cleaned up by state or federal authorities.

Prime Minister Tony Abbott and NSW Premier Barry O'Farrell granted affected communities access to disaster assistance after 203 families lost homes to fires around Springwood, Winmalee, Lithgow and Mt Victoria.

The massive fire complex west of Sydney tore through more than 50,000ha of bushland, forcing schools to close and hundreds of locals to flee.

But Blue Mountains Mayor Mark Greenhill says none of 210 properties destroyed by fire have been cleared.

He says families that lost everything are "sitting around waiting for something to happen" because rebuilding has stalled.

- AAP