University researchers are waiting for heavy rain over central Queensland, so they can find out where debris from flooding rivers ends up.
The researchers at CQUniversity are studying where garbage goes after being dumped into rivers that flow from Queensland's east coast.
They are trying to find out if debris washed into flooding rivers floats along the ocean in the same direction as other rubbish.
University researcher Scott Wilson says rivers discharge with greater velocity during floods.
"Under low flow conditions there's generally low loads ... conversely if there's a large event you get high loads entering into the systems," he said.
He says that could push flood debris further out to sea and knowing where it ends up will help clean-up efforts.
The researchers are planning to release tracking disks into rivers near Gladstone and are waiting for flooding rain over the catchments.
© ABC 2014
07:24 EST A severe weather warning has been issued for Sydney and parts of New South Wales, raising the prospect of damaging winds and heavy rainfall.