NSW Australia floods
Many properties, such as this one near Wee Waa, could remain isolated for weeks.
Thousands of people in northern New South Wales are facing weeks of isolation, as record floodwaters from Queensland cross the border into already swollen waterways.

The State Emergency Services says about 7,000 people are currently isolated around the state, including 2,000 at Wee Waa.

Around 1,700 people in Walgett could be stranded for up to a fortnight, while several hundred people living in Goodooga may be cut off for as long as eight weeks.

The towns of Lightning Ridge, Mundindi, Collarenebri and Bourke are also likely to be affected, along with many farms.

SES spokesman Phil Campbell says communities are stocking up and there will be helicopter support to fly in more supplies to the thousands who are stranded.

"That number's going to increase in coming weeks, as we have further towns and villages that are going to become isolated by these floodwaters as they move down the Gwydir and the Namoi and also from the other rivers coming in from Queensland," he said.

The SES is urging people needing resupply to contact it rather than the supermarkets.

"We have to make sure that we do supply people with essential items, so you can't ring up your local supermarket and order a whole lot of beer or something like that," Mr Campbell said.

Governor-General Quentin Bryce and her husband, Michael Bryce, flew from Canberra before visiting Moree's recovery centre.

She was also in Wee Waa meeting isolated landowners and members of the Namoi SES.

Ms Bryce says the flood has taken a terrible toll on the Moree community.

"This flood has very big implications for the economy here, this town depends so much on tourism," she said.

"It's missed out on the tourists coming back from the north, back to start the school year."

Receding danger

As the floodwaters recede in many communities, exhausted residents have been warned to protect themselves against infections during the long and arduous clean-up.

Doctor David Durheim, from Hunter New England Health, says floodwaters contain dead animals, rotten food, chemicals and faeces.

He says it is a recipe for gastro-intestinal illness and other diseases, particularly when people are tired, dehydrated and under emotional strain.

"Many flood waters have got either human faeces in them, animal faeces or chemical contaminants," Dr Durheim said.

"Anything that's been in contact with it, including toys, including food, including other items, may well have been contaminated, so it's very important that people practice personal hygiene, that they look after their personal health.

"We're very fortunate in that our town water supplies have not been affected and that water is safe to use.

"People who are on properties and have been relying on surface water, which is dam water or streams or rivers, that water's likely contaminated and they need to make sure that they use an alternate source."

Flood of rubbish

Moree Plains Shire Council says it is struggling to deal with the amount of flood debris being taken to the town's tip.

The council's waste manager, David Wolfenden, says the tip has itself been flooded with mattresses, white goods, furniture and other items.

"By the close of business we estimate 250 vehicles will come through the gate and a total of 200 tonnes. A lot of those vehicles are large trucks, semi trailers and the like," he said.

"To give you some sort of comparison, on a weekend we might get 100 vehicles and on a normal weekday we might get around 30 vehicles per day, so it's a significant number of vehicles and waste coming in."

He says the council is also offering free collections to get damaged items off the town's streets.

"On about Wednesday we'll have a contractor coming and doing a kerbside collection. That will bring a lot in," Mr Wolfenden said.

"What's not collected on the kerbside, we'll make some skip bins available, so i think there'll be some large volumes coming out in the next week or so."