Major General Smith said tasks will include "evacuation, aeromedical transport and search and rescue".
"Our emergency teams are tryiung to get into those communities, we have been since first light," QFES's Mark Roche told Sky News Australia.
"The reality is this is still a significant event. There's still a lot of rain, a lot of wind. It is hampering our effects, our ability to get in there.
"We expect this rain event to continue for a very long time."
Cyclone Debbie is the largest to hit the region since Cyclone Yasi in 2014 and could cost hundreds of millions in lost tourism revenue, insurance and clean-up.
Queensland Tourism Industry Council boss Daniel Gschwind said Hamilton Island and the Whitsundays generated about $700 million a year for the region.
The situation is no better on Airlie Beach, where some tourists haven't eaten in 24-hours.
"I just want to go home," distraught Melbourne woman Karina Calle, who was in Queensland for a holiday and had not eaten in 24 hours, told Channel Seven's Sunrise from cyclone-battered Airlie Beach.
"I came up with mum from Melbourne to have just some time away, we weren't expecting this."
"I'm trying to get some food and water at the moment, we've got nothing."
Ms Calle's fiance Travis Coutts told news.com.au that his future wife had been looking forward to spending some time with her mum ahead of their wedding on April 23.
Instead of a relaxing holiday, mother and daughter had to barricade themselves in a bathroom, pushing mattresses up against the windows of their hotel room, to wait out the worst of the storm, without power or airconditioning.
Mr Coutts said the couple had been ringing each other hourly and he felt helpless being so far away.
"They were petrified, it was a harrowing experience," he said.
He said mother and daughter flew in to Airlie Beach on Saturday and were told the resort was on high ground and they were safe.
But they didn't realise how bad the storm, which started just after 1pm yesterday and was still going seven hours later, would be.
Originally due to leave today, mother and daughter now won't be able to fly out until Friday, which is the first available flight they could get.
"It's been a tough couple of days," Mr Coutts said. "I just want her home and to look after her."
Meanwhile residents on Daydream Island are expected to be evacuated by ferry as drinking water runs low.
Airlie Beach resident Steve Andrew, 56, said he had already lost his business to Cyclone Ului in 2010 and now his home had been torn apart by Cyclone Debbie.
"This place is unliveable. I've got water pouring into the living room like a waterfall," he told the Whitsunday Times.
He said the violent second half of the cyclone was among the "scariest" moments of his life.
"I've never been scared like that before.
"You've got to give Mother Nature full respect in a storm like that, the sheer ferocity of it.
"It's still here and it's still sh***ing on us.
"It just looks like a bomb has hit this place."
Another local Dave Thompson, works at a caretaker at a motel in Airlie Beach, which was so badly damaged it will likely have to be demolished.
He said "I think I'll probably pack up and go now, that's enough".
Mr Thompson has lived in Airlie Beach for 18 years and has seen some pretty bad storms but "this one took the cake".
He said he narrowly avoided being injured when the whole back of the building fell away.
"I was in room nine but the windows came in and that was it," he said.
"Lucky I moved when I did because the whole back of the building came off anyway."
But the community spirit has kicked in, with Down Under Bar putting on a BBQ lunch on Wednesday and was serving free beers and sandwiches to the 50 people stranded there.
Little Vegas burgers had a queue down the street for hot food.
While Cyclone Debbie has been downgraded to a tropical low, the lingering weather system continues to cause heavy rain and high winds to the region.
The difficult conditions are hampering efforts to get food, water and other assistance to areas impacted by the cyclone.
Heavy rain was also causing flash flooding in Mackay on Wednesday, where rainfall reached 100mm per hour, according to the Bureau of Meteorology.
"In the Pioneer Basin there's been over 1000mm of rain in 48 hours. We normally see 1500-2000mm in a year," BOM Queensland Hydrology Manager Victoria Dodds said.
Authorities have released water from Somerset Dam, northwest of Brisbane ahead of predicted downpours from the remnants of the cyclone.
The weather system will likely impact residents as far south as Sydney on Thursday with cooler temperatures and rain expected.
More than 63,000 homes are without power, including in Mackay, Sarina, Airlie Beach and Proserpine and people stranded in the region have been told to expect more heavy rain and power shortages for days.
Queensland Premier Annastacia Palaszczuk said there was a lot of structural damage across the Whitsundays and the government was prioritising getting water to Daydream Island, where about 200 holiday-makers and 100 staff were running out.
"It's f***ed," Welsh tourist Tom Humphries told news.com.au at Airlie Beach.
"There was loads of wind, trees falling down and windows blown out in the next room and we've got no food left. It's a bit of a nightmare. We're getting cabin fever. It seems we're stuck here for a few days at least.
"I'm sure it's a beautiful place but for now I'm completely over it."
Charlotte Jenkins, who works at an Airlie Beach tour operator, told news.com.au she had spoken to several angry tourists.
"I do think airports should probably have told people," she said.
"They seem quite angry but they didn't take the advice, which was to leave. They're expecting responsibility to be taken by somebody else. Look at the weather, where you're going.
"Some people were saying on Saturday they'd been told to go north, which is the worst idea. They were saying 'we've got to get up there for a tour', I said 'this is more important'."
Tourists who have missed flights and buses are desperate to make new travel plans.
George, a Romanian living on the Gold Coast, said he was desperate to get out and was going to pay someone $100 to drive him "anywhere" until he realised the routes were flooded.
"The roads are all blocked," he said as he sat outside a closed McDonald's. "I'll just wait here."
Many tourists had missed flights and buses and were wondering what came next, with little information available and most phones not working. Some had found operating pay phones instead.
People are wandering the streets at a loss for what to do.
Tom Siberg, 22, from England is one of the tourists stranded in Airlie Beach.
"We got evacuated from a hostel down here and had to go to one higher up," he told news.com.au.
"We had the Whitsundays booked for Monday but obviously that's been postponed. We've had to stay an extra day and we couldn't pay for last night because the card machine wasn't working."
His friend Tom Cook-Neill added: "We don't know how we're going to get out. All the buses are going to be booked out."
Simon Myrevik, 21, from Finland, told news.com.au: "I've been here since Thursday and I just wanted to leave as soon as possible but I don't know when that is. Our bus was meant to be yesterday and we were planning to go to Magnetic Island on Friday."
Juliette DuPont, 18, said she and her friend from Belgium has been stuck in a hostel for days. "We put a mattress on the windows, one window wouldn't close.
"There is a bus driver who was with us and he said we can probably leave on Friday when the train starts and go to Townsville. We were supposed to leave this morning."
Eloise Haulotte, 19, added: "We just want electricity and a shower."
The Night Owl store with a generator has said it is about to open, a bakery is going to be selling bacon and eggs rolls and an IGA is expected to open later.
News.com.au reporter Emma Reynolds was in Airlie Beach overnight and said people woke up to scenes of devastation this morning, with boats washed up on the beach, trees smashed through roofs and windows shattered throughout the area.
The area's once-beautiful lagoon was filled with uprooted trees, and locals and business owners are starting to count the cost, with lights dangling from electrical wires and roads blocked with debris.
Ms Jenkins said she saw roofs flying off neighbour's buildings, her own fence blew down and trees were uprooted in her garden.
"It was so frustrating it took so long. It was the longest cyclone I've ever been in. I've always been on the edge but to be right in it was terrifying," she said.
"The noise of the wind, I couldn't see that much but what I could see was pretty scary."
The cyclone has left behind flooded roads littered with trees, and cars that seem to have been abandoned.
"These are typical rural Queensland roads. They couldn't get emergency services and SES out last night. If you hurt yourself you've got no one to come and help you, or you're risking their life to do it," she said.
At least one business has also been looted.
"There was looting at a local bar," she said. "The manager had boarded up broken windows and they'd gone in there and stolen alcohol.
"They're sending in the army so I'm not too worried."
The Whitsunday Islands as well as Bowen, Proserpine and the inland town of Collinsville were some of the areas hardest hit by the cyclone.
As daylight started to break Premier Annastacia Palaszczuk questioned whether homes in the region could sustain eight hours of "horrendous force".
At a later press conference she said a lot of families would wake up this morning and be "shell-shocked" by the devastation.
"For many people this morning, they are waking up and they are seeing the devastation that has happened in their communities. Our hearts go out to them," she told reporters on Wednesday.
"There would be nothing more tragic than waking up and seeing walls that have come in from your houses, roofs that have gone off, and debris that is lying across your roads."
The premier said the priority was clearing roads into hard hit communities in the Whitsunday region, getting emergency supplies in, and restoring power and communication lines.
She said power outages had made some food supplies in supermarkets unsafe to eat, and the government would be sending more supplies into communities.
"We've already seen some significant structural damage ... a lot of structural damage across that Whitsunday region," she said.
Deputy Police Commissioner Steve Gollschewski said up to half of the power network was out, and the premier warned it could take up to a week to restore supplies.
"People could be without power even up to a week or over a week. Some places will be able to be restored quickly. We do not know that at this stage until we get the assessments in," Ms Palaszczuk said.
Road cuts are hampering efforts to fix the power network. The Bruce Highway is cut in three places, just north of Bowen, at Airlie Beach and also south of Mackay.
"In some places you have large trees wrapped up in live wires," Roads, Energy and Water Minister Mark Bailey said.
Deputy Commissioner Steve Gollschewski said the damage was focused on the Whitsunday region, and the communities of Bowen, Airlie Beach, Proserpine, and the inland town of Collinsville.
"Those areas and the Whitsunday Islands remain difficult for us to contact and to get into," he said.
"We're progressively getting information out of there (and) I'm pleased to say the information that we're getting is while there are significant damage there are no injured people."