High intensity rainfall between 12–14 January 2011 caused major flooding across much of the western and central parts of the Australian state of Victoria. Several follow-up heavy rainfall events including Tropical Low Yasi caused repeated flash flooding in affected areas in early February in many of the communities affected by January's floods.
Many of the towns were previously affected by floods in September 2010, however the 2011 event was more severe, affecting at least four times as many properties with thousands of evacuations being called for by the State Emergency Service. As of 18 January, more than 51 communities had been affected by the floods. A total of over 1,730 properties had been flooded. Over 17,000 homes lost their electricity supply. The floods forced VicRoads to close hundreds of roads; and train services were also disrupted. The floods devastated farms with 51,700 hectares of pasture and 41,200 hectares of field crops flooded and 6,106 sheep killed. The Victorian Employers Chamber of Commerce and Victorian Farmers Union initially estimated that damages would amount to hundreds of millions of dollars, but the Department of Primary Industries later calculated a damage bill of up to A$ 2 billion.
Kevin Parkyn, a senior forecaster with the Bureau of Meteorology said, "Victoria is experiencing one of its worst flood events in its history" after "a week in which rainfall totals have been smashed in parts of Victoria." Bureau of Meteorology senior forecaster Terry Ryan said, "It's the worst flood in western Victoria in their history as far as our records go in terms of the depth of water and the number of places affected." The Premier of Victoria, Ted Baillieu, has described it as "one of the biggest floods in the state's history."
Background
The strongest La Niña event since 1973 which fuelled the extensive flooding across Victoria in September 2010, brought wetter conditions across eastern Australia including the 2010–11 Queensland floods. An already soaked state had the wettest January in its recorded history in January 2011.
A deepening low pressure trough over south-east Australia, fed with tropical moisture from the monsoon across the state as well as northern Tasmania, southern New South Wales and eastern parts of South Australia.
During the downpour across the state flash flooding occurred in places such as Halls Gap and Beaufort, resulting in damage to businesses and homes. However, it was not until the downpour began to subside (and fair weather returned) that the accumulated water caused waterways across the region gradually to swell. As waterways began to break their banks, evacuations were called. Despite clearing conditions, flooding continued to spread during January and into February 2011 as it developed into what was increasingly described by the media as an "inland sea" across agricultural north-west Victoria.
Early warning and evacuation
Rising rivers led to evacuations in many other towns in central and western Victoria:
Allansford & Jubilee Park - 10 people evacuated on 16 January to Archie Graham Centre. Frank Street and Station Street sandbagged. Charlton evacuated to Donald Glenorchy Rupanyup Carisbrook - 1,000 evacuated to Maryborough Creswick Halls Gap Kerang Quambatook Warracknabeal Quantong Dimboola Jeparit Kerang - 224 residents evacuated Horsham - 1,000 households told to evacuate Cohuna Barham Beulah Dimboola Nelson
Major waterways affected
Wimmera River
Loddon River
Campaspe River
Avoca River
Hopkins River
Werribee River
Goulburn River
Yarra River
Mount Emu Creek
Yarriambiack Creek
Yarrowee River
Glenelg River
Settlements affected
Beaufort - creeks running to Lake Beaufort broke their banks, flooding the town's main street and over 70 houses