Australia's east coast has been pounded by rain, wind and surf for a week, with Brisbane recording its highest daily rainfall in half a century.

A tropical cyclone weakened into a tropical low weather system on Saturday as it approached Brisbane, Australia’s third-most populous city, bringing flooding rain that was expected to lash the coastal region for days.

More than 300,000 properties are without power in Queensland and New South Wales as the storm approaches.

Tropical Cyclone Alfred is forecast to cross the south-east Queensland coast this week, bringing destructive winds and the risk of life-threatening flooding. The system is expected to make landfall between the Gold Coast and southern parts of the Wide Bay region as a category two cyclone.

Fallen trees across the region have already damaged power lines, homes and cars, while the Gold Coast's renowned beaches have become steep sandy cliffs after days of relentless erosion.

Heavy rain will continue to lash a region of the Australian east coast for days, even though it avoided the destructive winds of its first tropical cyclone in 51 years, officials have said. One person was confirmed dead and several others were injured during the bad weather.

Cyclone Alfred - which has been downgraded from a cyclone to a tropical low - has caused flooding, damage to buildings and left thousands without power across the eastern coast of Australia. Millions of people across Queensland and north New South Wales have been affected.