2000s Australian drought
The 2000s drought in Australia, also known as the millennium drought, is said by some to be the worst drought recorded since European settlement.
The drought affected most of southern Australia, including its largest cities and largest agricultural region. It commenced with low rainfall conditions in late 1996 and through 1997, and worsened through particularly dry years in 2001 and 2002. By 2003 it was recognised as the worst drought on record.
The year 2006 was the driest on record for many parts of the country and conditions remained hot and dry through to early 2010. The emergence of La Niña weather conditions in 2010 rapidly ended the drought, and led to floods in some locations, particularly in central and southern Queensland.
The drought placed extreme pressure on agricultural production and urban water supply in much of southern Australia. It has led to the construction of six major seawater desalination plants to provide water to Australia's major cities, and to changes in the management of water in the Murray–Darling basin, particularly the formation of the Murray–Darling Basin Authority.
Prelude to drought
Beginning in the second half of 1991, a very severe drought occurred throughout Queensland which intensified in 1994 and 1995 to become the worst on record.By October 1994, part of the upper Darling River system had collapsed and the Condamine River had reverted to a series of ponds. Across the state 40% of Queensland was drought declared. From July to August 1995 the drought was further influenced by a strong El Niño weather pattern associated with high temperatures. According to Primary Industries Minister, Ed Casey, "the drought affected region stretched in a 200 km to 300 km wide strip from Stanthorpe to Charters Towers". So few wheat and barley crops survived, about half the usual for that year, that grains had to be imported from other states.
Geographic and seasonal characteristics, and compounding factors
The Bureau of Meteorology has characterised the Millennium Drought as primarily affecting:- Southern Australia.
- Cool season rainfall, other than for Tasmania where rainfall was well below historical averages in both warm and cool seasons.
The effects of the drought on water availability was compounded by historically high temperatures over the same period. The Bureau of Meteorology's head of climate analysis, David Jones, released statistics showing that in 2007 South Australia, NSW, Victoria, the ACT and the Murray–Darling basin all set temperature records by a very large margin. 2007 was the eleventh year in a row that the Murray–Darling basin had experienced above average temperatures and was Australia's sixth-warmest year on record. Jones warned that "There is absolutely no debate that Australia is warming... it may be time to stop describing south-eastern Australia as gripped by drought and instead accept the extreme dry as permanent."
Timeline
1996 to 2000: patchy rainfall in the south-east
Dry conditions began to emerge in south-eastern Australia during late 1996 and accentuated during the strong 1997 El Niño event. Rainfall in 1998, 1999 and 2000 was closer to average, with isolated areas affected by rainfall well below average.2001 to 2005: El Niño brings on strong drought conditions
According to the Bureau of Meteorology, much of eastern Australia experienced a dry 2001. 2002 was one of Australia's driest and warmest years on record, with 'remarkably widespread' dry conditions, particularly in the eastern half of the country which was again affected by El Niño conditions. It was, at the time, Australia's fourth-driest year since 1900.The El Niño weather pattern broke down during 2003 but occasional strong rainfall in 2003 and 2004 failed to alleviate the cumulative effect of persistently low rainfall in south-eastern Australia, with some measurement stations having recorded below average rainfall for eight consecutive years. Rainfall in early 2005 remained below average, and better rainfall in the second half of the year again failed to break continuing drought conditions in the south-east.
2006 and 2007: extreme dry and hot conditions in the Murray–Darling basin
South-east Australia experienced its second-driest year on record in 2006, particularly affecting the major agricultural region of the Murray–Darling basin. Despite slightly above normal summer/autumn rainfall, the late-winter to mid-spring rainfalls failed, resulting in the 2006 annual rainfall being 40 to 60% below normal over most of southern Australia. The average rainfall in the state of South Australia was the lowest since 1900 with only of rain recorded compared to the normal winter/spring average of. Across Victoria and the Murray–Darling Basin the season was the second-driest since 1900. While New South Wales' rainfall was boosted by above normal falls along the north coast of the state, the state's average rainfall for the season was the third lowest since 1900. The situation was exacerbated by temperatures being the highest on record since the 1950s.In early 2007, senior weather forecasters predicted that the drought would ease along the east coast with a return to average rainfall from late February 2007. Forecasters believed that the El Niño effect that had been driving the drought since 2006 had ended.
However, this did not turn out to be correct as 2007 saw record temperatures across the south of Australia, and only patchy rain. Promising early year rains transitioned into a very dry July–October period. Heavy rainfall in June and July, particularly in coastal regions of New South Wales and in Victoria's Gippsland region, together with tentative forecasts of a La Niña event, brought hope that the drought may have ended. In August 2007, the Darling River flowed again after nearly a year of no flows; however, the Murray-Darling Basin experienced their seventh consecutive year of below-average rain and inflows into the Basin during the winter of 2007 were still amongst the lowest on record, though marginally better than those of the winter of 2006 which had been the driest on record.
At the end of 2007 the Bureau of Meteorology estimated that south-eastern Australia had missed the equivalent of a full year's rain in the previous 11 years.
2008 and 2009: continuing hot and dry conditions
2008 and 2009 saw continuing hot and dry conditions in south-eastern Australia, with occasional heavy rainfall failing to break the continuing drought. The effects of the drought were exacerbated by Australia's second-hottest year on record in 2009, with record-breaking heatwaves in January, February and the second half of the year.The drought in Sydney eased around April 2008 and Sydney's main water catchments reached 65 percent, 25 per cent fuller than they were at the same time the previous year. However, Victoria remained drought affected, with Melbourne's water supplies dipping to around 30% by July 2008. In Tasmania drought conditions worsened in 2008, with many areas reporting no significant rainfall for three years.
2010 and 2011: La Niña finally breaks the drought
Australia's weather pattern transitioned rapidly to a wet La Niña pattern during the autumn of 2010, resulting in record-breaking rains in the Murray-Darling basin and well above average rainfall across the south-east. For many locations this was the first year of above-average rainfall since 1996. The rainfall dramatically increased surface water storage and soil moisture, effectively ending the drought in the south-east.While 70% of New South Wales was in drought at the beginning of 2010, the entire state was officially out of drought by December. The entire state experienced its wettest spring on record. Several rivers, including rivers in the outback had flooded several times, and many dams were overflowing, including the Burrendong, Burrinjuck and Pindari Dams. Canberra's dams were above 90% capacity.
The 2010 Victorian storms in March did little to help Melbourne's storage levels, but steady winter rains, and the 2010 Victorian floods in September, rapidly increased storage levels. Melbourne also recorded its average annual rainfall in 2010 for the first time since 1996, and its wettest spring since 1993. By 2011, Victoria was drought free for the first time in almost 15 years and was instead gripped by very wet conditions and severe flooding.
Queensland experienced heavy storms in December 2010 and January 2011, resulting in widespread flooding.
Despite Western Australia experiencing its fifth-wettest spring on record, drought in the South West, Gascoyne and Pilbara regions of Western Australia's intensified in 2010, with the regions experiencing their driest year on record. Perth's dams registered their lowest inflows on record with the city itself recording its third-driest year on record, along with the hottest spring on record.
In South Australia, only two regions in the Riverland remained in drought. Heavy rains elsewhere led to bumper harvests over much of the state, this in turn led to the largest mouse plague since 1993 across parts of South Australia, West Australia and Victoria. While some farmers tried to replant, in some areas many gave up as millions of mice covered their fields. Farmers often characterised the plague as being worse than the drought.