Mr Key has spoken to Australian Prime Minister Julia Gillard about how New Zealand could best help but it had already been decided that up to 60 Fire Service personnel would leave within a few days, including urban search and rescue teams dispatched to Canterbury following the massive September 4 earthquake.
"They have quite a number of specialist skills that they can provide," Mr Key said.
"The police also have specialist teams in terms of divers and other skills that they might be able to provide."
As well, Civil Defence would send a team to replace a 15-strong one currently there but due home in 10 days, and New Zealand Defence Force personnel would be made available.
"It's quite possible there will be a reasonably large contingent from defence. They (Australia) may just want labouring and grunt work, which they need (people) on the ground for.
"One of the big issues that's likely to take place in Queensland, and we've seen it here in New Zealand when we've faced similar disasters, is that obviously the stress and the strain and the fatigue starts to build up.
"So those who are on the ground who are providing great support obviously get extremely tired in the conditions that they face. Having fresh arms and legs is very important."
Air New Zealand had offered help getting the emergency personnel to Queensland but it was also possible the Defence Force would fly them over.
There had been no reports of New Zealanders being seriously injured or killed but Mr Key refused to rule that out, given the number of New Zealanders either holidaying or working in Queensland.
New Zealanders concerned about loved ones in Queensland should try to contact them directly but, if that failed, they should contact MFAT on 0800 432 111. Five New Zealanders had already been located through that service, Mr Key said.
Those booked to travel to Queensland should use common sense, he said.
"Without stating the obvious, three-quarters of Queensland has been reported as a disaster zone so New Zealanders will want to consider carefully about whether it makes sense for them to travel at this time."
MFAT said there were over 150,000 New Zealanders in Queensland, many of whom were likely to be in flood affected areas.
"We are continuing to monitor the situation and are in touch with Australian authorities."
Mr Key spoke to Ms Gillard earlier this week and offered support and condolences.
"New Zealand had a very difficult year in 2010 so we know absolutely the type of emotions that will be going through the community in Australia," Mr Key said.
"Queensland provided an enormous amount of support to New Zealand when it came to the Pike River disaster and it's only fitting that we do whatever we can to try and support Queensland in return."
The New Zealand Red Cross today announced it had launched an appeal and Mr Key said it was likely the Government would make some sort of contribution.
Donations to the Red Cross could be made online at www.redcross.org.nz/donate or by sending a cheque (made payable to: New Zealand Red Cross) to: Red Cross Flood Response and Recovery Fund, Freepost 232690, PO Box 12140, Thorndon, Wellington 6144.
The ANZ bank has also opened an account to take donations for the Australian flood relief which will go via the NZ Red Cross. People can make a donation to the fund at any ANZ branch to the ANZ (NZ) Australian Floods Appeal at account number 01 1839 0224522 00 or via internet banking.