The floods have washed away key tracks linking mines to ports, shutting down several mines and costing the industry an estimated $1 billion in production so far.
With 75 per cent of mines in the state affected by the floods, coal prices have started to rise.
The price of Queensland coking coal has jumped to $253 (£164) per tonne from $225 in the past three weeks and are expected to rise further.
"It will hit in a number of ways, although it's perhaps too early to put a precise figure on the economic impact.
"The biggest short term impact in terms of dollars is the disruption to coal exports, and some figures put that at $400 million dollars a week."
Thousands of properties have been flooded and livestock left stranded on islands in the vast inland muddy sea.
Queensland also accounts for nearly all of the country's sugar production and export, but this year will need to buy more raw sugar from rivals Brazil and Thailand to meet sales commitments because of drenched cane fields.
The industry group Cane growers estimated up to 18 per cent of the 2010 cane harvest has been abandoned and early plantings for 2011's crop were under water.
Australia is also the world's fourth largest wheat exporter. Crop analysts and farmers said up to 50 per cent of the 2010-11 crop would be downgraded.
Widespread damage to crops in Queensland is also likely to push up fruit, vegetable and dairy prices by as much as 50 per cent due to the crop losses that are being experienced.
Tropical fruits are stranded in the wet.
About $4 million worth of pineapples are stranded in the Rockhampton area after floodwaters cut road access to the south of the city.
Around $500,000 worth of lychees and a similar amount in mangoes are also awaiting urgent distribution.