20,000 homes at risk as Brisbane floods

The sun emerged after a week of monsoon rain over Queensland's capital - but locals were told it was a false dawn.

Unprecedented rainfall over much of the northeast Australian state has already devastated scores of towns and cities, including Rockhampton and Toowoomba.

At least 12 people are known to have died and 90 are missing after torrents of water tore through Lockyer Valley.

An area the size of France and Germany has been crippled by floodwaters now on course for Brisbane.

Officials estimate the city's swollen river will peak at 5.5 metres early on Thursday and will not drop until Saturday.

Australia's Prime Minister Julia Gillard told Sky News: "People do have to be prepared for the death toll to rise."

Although the majority of Brisbane's two million people are safe due to the city's hilly suburbs, thousands of properties in low-lying areas are likely to be inundated.

The number of people evacuated is expected to rise as floodwaters filled suburban creeks and tributaries.

Temporary accommodation has been set up for those forced from their homes and sandbags made available across the city.

The swollen muddy river has already broken its banks in parts of the city centre, flooding riverside restaurants and bars.

Thursday's predicted peak is slightly higher than in 1974 when vast areas of Australia's third largest city were plunged underwater.

After the devastation of that summer, a dam was built west of Brisbane to prevent such an event happening again.

Barely three years ago, the Wivenhoe Dam looked more like a puddle.

Drought conditions in the region meant residents lived with strict water restrictions as the dam capacity hovered around 30%.

Now, after monsoon rains for the best part of two months, Wivenhoe is bloated to 190% of its capacity.

Authorities have no choice but to release an extraordinary amount of water from the dam to save the structure from giving way.

Local reports said 490,000ML (megalitres) of water a day was being let out - an overflow that Brisbane is bearing the brunt of as it makes its way to the Pacific Ocean.