Massive flooding in Australia cuts off city of 75,000

The arrival of the new year has brought continued misery to northeast Australia, where unprecedented flooding continues in the wake of weeks of torrential rains. The floods have killed at least ten people and covered an area the size of France and Germany combined, cutting off the coastal city of Rockhampton. Today, the military was forced to fly in food, water, and other supplies into Rockhampton, a city of 75,000, due to the lack of unflooded roads into the city. The local airport, all access roads, and all rail lines into the city are closed. The flooding has affected at least 21 other towns, and 200,000 people in northeast Australia. Australian Prime Minister Julia Gillard stated last week, "Some communities are seeing flood waters higher than they've seen in decades, and for some communities flood waters have never reached these levels before [in] the time that we have been recording floods." According to the National Climatic Data Center, springtime in Australia (September - November) had precipitation 125% of normal--the wettest spring in the country since records began 111 years ago. Some sections of coastal Queensland received over 4 feet (1200 mm) of rain from September through November. Rainfall in Queensland and all of eastern Australia in December was the greatest on record, and the year 2010 was the rainiest year on record for Queensland. The heavy rains are due, in part, to the moderate to strong La Niña event that has been in place since July. The relatively warm waters that accumulate off the northeast coast of Australia during a La Niña typically cause heavy rains over Queensland.


Figure 1. Comparison of river conditions in Queensland from today to December 30, 2010. While some rivers have fallen below major flood stage, the Fitzroy River at Rockhampton is rising, and may peak at levels not seen since 1918 on Wednesday. Image credit: Australian Bureau of Meteorology.


Figure 2. Rainfall in Queensland, Australia for December, 2010. Image credit: Australian Bureau of Meteorology.

The rains over Queensland continued yesterday and today, with many of the flooded regions receiving 1/2 - 1 inch (about 12 - 25 mm) of rain. Total rainfall amounts in the flood region over the past month are generally in the 16 - 24 inch range (400 - 600 mm). Predicted rainfall amounts for the next two days in the flooded region are less than 1/2 inch (12 mm), which should allow for river levels to peak by Tuesday or Wednesday, then slowly fall. However, heavy rains are predicted to affect the area again by Thursday, and it may be several weeks before the summer rains ease enough to allow all of Queensland's rivers to retreat below flood stage. Damage to infrastructure in Australia has been estimated at over $1 billion by the government, and economists have estimated the Australian economy will suffer an additional $6 billion in damage over the coming months due to reduced exports, according to insurance company AIR Worldwide. Queensland is Australia's top coal-producing state, and coal mining and delivery operations are being severely hampered by the flooding. Damage to agriculture is currently estimated at $400 million, and is expected to rise.

Jeff Masters