Donovan said a second crocodile placed itself underneath the house, after he spotted it through a window.
The report said he positioned himself in the highest place he could find, taking refuge on a billiard table which he packed with supplies.
"(The water) just kept going up and up and up, and it was just an inch or so above the nets where the balls are collected by the billiard table," he said.
"And I thought, 'Well, the next step is the roof, I'm out of here'."
Donovan was eventually spotted by a passing helicopter which had gone to check on him after he failed to answer his satellite phone. Officials then alerted a local fishermen who rescued him.
Saltwater crocodiles are a common feature of Australia's tropical north and kill an average of two people a year.