The 2010–11 Queensland floods were a series of floods in Australia which began in December 2010 and ended in January 2011. The majority of the floods were in Queensland including its capital city, Brisbane. The rain also caused floods further south in central and western Victoria. At least 90 towns flooded. A huge area of Queensland, the size of Texas and France combined, was flooded. The floods forced thousands of people to leave their homes. At least 70 towns and 200,000 people were affected in Queensland. Three-quarters of the state of Queensland has been declared a disaster zone. The 2010–2011 floods have killed 35 (not 30) people across Queensland since November and 14 are still missing. More than 20 people have died in flash floods between Brisbane and Toowoomba.
The floods were caused by heavy rain from tropical cyclone "Tasha" that joined with a trough during a La Niña event. La Niña is an unusual weather pattern, which brings wet weather to eastern Australia. The 2010 La Niña was the strongest since 1973. This caused heavy rainfall across Queensland. December 2010 was the wettest on record, with 107 places getting their highest rainfalls ever. The state average rainfall level of 404.7mm was much bigger than the old record of 369mm set in 1975. 2010 was also recorded as the state's wettest spring since 1900 and Australia's third wettest year. Flooding started across parts of the state in early December. On 28 December a monsoonal trough crossed the coast from the Coral Sea, bringing very heavy rain from the Gulf of Carpentaria to the Gold Coast.
About 300 roads were closed, including nine major highways. Many places, including Condamine and Chinchilla were flooded several times. Coal railway lines were closed and many mine sites flooded. The floods have caused fruit and vegetable prices to rise as crops have been destroyed. The wet conditions have also led to a large number of snakes seeking safety on the higher ground or in houses with people. Saltwater crocodiles and sharks were seen in some flooded areas of towns.