Toxic pollution from flooded farms and towns along Australia's Queensland coast will have a disastrous impact on the Great Barrier Reef's corals and will likely have a significant impact on dugongs, turtles and other marine life, WWF warned Monday.

"In addition to the terrible costs to farmers and communities in Queensland, we will also see a major and extremely harmful decline in water quality on the Great Barrier Reef," said WWF spokesman Nick Heath.

Heath said the restoration of important woodlands in flood prone catchment areas of the Fitzroy River and Murray Darling Basin would help protect communities and the marine environment from future floods.

"Today's floods are bigger, dirtier and more dangerous from excessive tree clearing, overgrazing and soil compaction. As a result less water infiltrates deep into the soil, increasing the size and erosive intensity of floods," he said.

Rebuilding

"While the current floods would still have occurred, trees and wetlands slow flood waters down and absorb water, lessening the impact of the flood. We can better prepare for future floods by bringing trees back into previously cleared catchment areas."

Climate change is likely to deepen the cycle of drought and floods, with further loss of top soil followed by bigger rainfall events, and therefore increase the damage caused by floods.

Heath said the need to rebuild farms presented an opportunity to introduce best-practice farm design and management in reef catchment areas that would boost future profitability, better prepare farms for flood recovery and significantly reduce the future impact of farming on the Great Barrier Reef.

"As devastating and tragic as these floods are, they also provide a chance to introduce newer and better technologies that will reduce pollution and increase profits," he said.

"Better management and design of our farms can reduce the risks to people, livelihoods and wildlife and also lead to greater profits further down the track by increasing deep infiltration and soil moisture, improved topsoil retention and therefore productivity."

Over the past 150 years sediment inflow onto the Great Barrier Reef has increased four to five times, and five to 10 fold for some catchments, while inorganic nitrogen and phosphorous continue to enter the Great Barrier Reef at enhanced levels, according to the Australian Government's Outlook Report.