Rainfall deficiencies and water availability
No formally monitored drought periods for January
Rainfall for November 2021 was above or very much above average for most of mainland Australia, clearing serious rainfall deficiencies for the period commencing April 2020 from Queensland.
Rainfall for December 2021 was very much below average along the southern coastline of the mainland and across Tasmania, and below average for much of the southern half of Western Australia and parts of Central Australia and the inland north. December rainfall was above average for the Top End in the Northern Territory; Cape York Peninsula in Queensland; much of eastern New South Wales, extending into south-eastern Queensland and far eastern Victoria; and in some parts of upper western New South Wales to southern inland Queensland, and pockets of Queensland's tropics.
The Climate Outlook released on 6 January 2022 indicates rainfall for February to April is likely to be above median for parts of mainland eastern Australia, and parts of the Northern Territory.
Multi-year rainfall deficiencies which originated during the 2017–2019 drought remain over large parts of the country, with very large accumulated rainfall anomalies for some areas. However for recent months, seasonal conditions have improved over large areas, and water storages have increased across much of the country.
Many areas experiencing rainfall deficiencies for periods longer than 24 months have typically experienced below average rainfall between April and October, which is consistent with the long term trends in rainfall reduction over southern Australia and along the Great Dividing Range as discussed in State of the Climate 2020.
Root-zone soil moisture (soil moisture in the top 100 cm) for December 2021 was above average across most of New South Wales, eastern Queensland, eastern Victoria, much of South Australia, parts of south-east and central Western Australia, the Top End, and parts of Cape York Peninsula in Queensland. In the north-east of the Murray–Darling Basin, near Toowoomba, and in the east, near Tamworth, the highest soil moisture levels for December were recorded.
Soil moisture was below average for western Tasmania, western Victoria and south-eastern South Australia, large parts of the South West Land Division and southern Western Australia, and some parts of the northern tropics, mostly in inland areas.
Soil moisture has generally decreased across most of Australia, following near-saturated soils resulting from record November rainfall. Soil moisture remained similar to the previous month across parts of the east coast.
Saturated soil conditions, especially across eastern Australia, may result in large inflows into water storages if further rainfall occurs during the coming months. Wet soils, high streamflows, and full storages increase the risk of flooding.
- Record November rainfall cleared deficiencies existing since April 2020, with no short- to medium-term deficiency periods currently being monitored
- December rainfall was very much below average along the southern coastline of the mainland and across Tasmania
- Storages remain low in Central Queensland but are in a better position compared to the same time last year
- Wivenhoe in South East Queensland had an increase in storage volume during December but is still well below full capacity
- Storages in New South Wales and the Australian Capital Territory reached 100% and started to spill during December
- Many storages in the Murray–Darling Basin are above full capacity
South East and Central Queensland storages remain low
South East Queensland received average to above average rainfall which resulted in an increase in storage levels but dams are still well below capacity. Wivenhoe, the largest storage, increased by 6.4% during December but is still below 50% capacity.
In Central Queensland, rainfall has been average for the majority of the area except for the west which experienced below to very much below average rainfall. Following the significant increase in storage volume in the Bundaberg system in November, the water in storage decreased slightly in December by 1.5% to 51.7% of capacity. However, this is still higher than the same time last year when it was at 40.6%. In the Nogoa Mackenzie system, storage levels continued to increase, and by the end of December, the storage volume had increased another 3.6%, however, the volume is still very low at 27.8% of capacity.
Storage levels in the Murray–Darling Basin continued to increase significantly
In much of the Murray–Darling Basin December rainfall was above average or close to average, except for the Victorian and South Australian parts. This has resulted in many storages in New South Wales and the Australian Capital Territory reaching 100% and starting to spill. The total water storage in the Murray–Darling Basin decreased by less than 1% for December to 90%, ending the run of 3 consecutive months of increases, however some of the decreases were due to storage operations. Compared to the same time last year, when the total storage volume was only 57%, the water storages are in a significantly better position.
The total storage in the northern Basin increased by 1% to 91.9% of capacity (4 272 GL) at the end of December. This is the highest level since May 2012 and a significant increase from the same time last year when it was only 25.6%. In the northern Basin, 6 out of 14 storages are above their full capacities with another 5 greater than 98%. The biggest increases in storage volumes occurred in Leslie (22%) and Cooby Creek (15.7%).
The total storage in the southern Basin (comprising more than 80% of the total storage volume in the Basin) decreased slightly by 1.1% to 89.2% (18 428 GL) of capacity in December. This is still considerably higher than the same time last year when it was only 64.5%. Most of the storages in the southern Basin are at or near full capacity. At the end of December, Hume dam was at 96.8% of capacity, a decrease of 1.5% from last month. During the early part of December, releases were made to meet irrigation demands and environmental requirements and it is expected the levels within Hume dam will continue to decrease over the next few months.
In the Lachlan valley, Lake Cargelligo increased by 67.5% during the month of December as a result of the flood waters resulting from above average rainfall. The levels within the Menindee Lakes system started to decrease during December as releases were made to reduce the storages to accommodate forecast flows from the upstream tributaries and at the end of December was at 93.1%.
Further detail on individual Murray–Darling Basin catchments can be found in the Murray–Darling Basin Information Portal.
Product code: IDCKGD0AR0
A very dry month for the southeastern mainland increases rainfall deficiencies
Soil moisture details are reported when there are periods of significant rainfall deficits.
Soil moisture data is from the Bureau's Australian Water Resources Assessment Landscape (AWRA-L) model, developed through the Water Information Research and Development Alliance between the Bureau and CSIRO.
See: Australian Water Outlook: Soil moisture.
For the week to 25 January 2021, rainfall was recorded in northern Western Australia, the Northern Territory, Queensland, South Australia and New South Wales.
At the start of the week, surface troughs extended down the west coast, across the north and down through eastern Australia, with a low pressure system located over south-west Queensland. Widespread moderate falls were recorded in the Gascoyne and Kimberley in Western Australia, eastern and southern parts of the Northern Territory, western and southern Queensland, and northern and eastern New South Wales.
In the middle of the week, a low pressure system was located over inland South Australia, with an associated trough extending north. Widespread moderate falls were recorded over South Australia, particularly around the Eyre Peninsula, southern parts of the Northern Territory, and the Kimberley. Moderate to locally heavy falls were also recorded in the north tropical coast of Queensland.
A monsoon trough was located across far northern Australia, and extended to a tropical low off the Kimberley coast in Western Australia, and produced widespread showers and thunderstorms, with moderate falls across most of the northern tropics.
In the last part of the week, the low and trough over South Australia was near-stationary, while another trough extended across inland western Queensland, western New South Wales, and Victoria. The systems continued to bring moderate falls to the eastern half of South Australia. As the second trough moved further eastwards, moderate falls were recorded in north-east South Australia, western Queensland, northern and eastern parts of the Northern Territory, and across the far northern tropics.
Rainfall totals in excess of 200 mm were recorded in the Eastern Eyre Peninsula District in South Australia, isolated spots in the Manning District in New South Wales, the Darwin – Daly District in the Northern Territory, and isolated parts of the north tropical coast of Queensland, including the highest weekly total of 265 mm at Mount Sophia.
Rainfall totals in excess of 100 mm were recorded across parts of the Kimberley, parts of the north-west coastal Top End in the Northern Territory, pockets of the south-west and north tropical coast of Queensland, and areas of the north-east and southern South Australia.
Rainfall totals between 50 mm and 100 mm were recorded in the Kimberley, the north and east of the Northern Territory, western Queensland and spots in the state's northern tropics and south-east, north-west and north-east New South Wales, and much of the eastern half of South Australia.
Rainfall totals of 10 mm to 50 mm were recorded in remaining areas of the Kimberley and in the Gascoyne in Western Australia, most remaining areas of the Northern Territory, most of Queensland except an area of the central coast, and most of northern and eastern New South Wales.
Impact of recent rainfall on deficits
No large-scale serious or severe rainfall deficiencies are currently present. Rainfall analyses are available for standard periods out to 48 months.
Product code: IDCKGRWAR0