Water in Australia

Water in Australia provides a countrywide picture of water availability and use in a particular financial year. Water in Australia 2017–18 covers the period 1 July 2017 to 30 June 2018 and key messages for this year were:

Read the full Water in Australia 2017–18 report (14.7MB).

You can also access data used in the report through Regional Water Information, and you can download high resolution images.

Monthly Water Update provides a regular snapshot of rainfall, streamflow, stream salinity and storage volumes for the previous month.

For further information, please contact us.

 



Below–average rainfall and streamflow conditions in the east

Australia's mean rainfall for the year 2017–18 was 441 mm, which is 4 per cent below the July 1911 to June 2018 mean of 461 mm and 26 per cent lower than the mean rainfall for the 2016–17 year (592 mm). There was a contrast in rainfall from the west to east. Rainfall in the country's west was generally average to above average while rainfall in most of the east was lower than average.

Rainfall was lower than average across much of the southeast of the continent, covering large parts of New South Wales, South Australia, southern Queensland and Victoria. Parts of these areas experienced serious to severe rainfall deficiencies. Rainfall was higher than average for much of the Northern Territory Top End, the eastern part of Western Australia and neighbouring areas of western South Australia.

The spatial distribution of annual streamflow conditions mostly followed that of the annual rainfall. Average to lower–than–average annual flows were dominant in all States and Territories except for the Northern Territory. Five per cent of gauges across the country recorded their lowest flows since 1975; most of these gauges were in New South Wales. Average to higher–than–average flows were mostly recorded in the tropical north and along the northeast coast. In Queensland, average to higher–than–average flows were mostly observed in the north and lower–than–average flows were mostly observed in the south.

Map of Australia showing relative rainfall and streamflow conditions for 2017-18. Streamflow Monitoring sites are mainly in the east, north and southwest.
			Rainfall in the country's west was generally average to above average while rainfall across eastern Australia was below average to very much below average over large areas.
			Average to lower-than-average annual flows were dominant in all States and Territories except the Northern Territory. Average to higher-than-average flows were dominant in the tropical north and along the northeast coast. Lower-than-average flows were dominant in the Murray-Darling Basin, as well as along the South East Coast drainage division.
			For more detail, visit the Regional Water Information website at http://www.bom.gov.au/water/rwi/#ra_dc/001/2018 and http://www.bom.gov.au/water/rwi/#sf_dc/001/2018.

Stream water quality was fresh (median salinity <500 mg/L) at 61 per cent of the monitoring sites analysed in 2017–18. These sites were mostly located in areas with higher rainfall, along the east coast. In contrast, many streams in Western Australia and South Australia had high salinities.

 



Drought in the Murray–Darling Basin

The Murray–Darling Basin climate has a large natural variability. Recently there has been a shift towards drier conditions across much of the basin including a reduction in annual rainfall.

The 2017–18 year was particularly dry for the Murray–Darling Basin with an annual rainfall of 340 mm, which was 28 per cent below the long–term mean. About half of the basin experienced deficiencies in rainfall. The most affected areas were in New South Wales and much of southern inland Queensland. Three–quarters of the basin had soil moisture deficiencies, especially in the north. Fifty–six per cent of the basin's streamflow gauges recorded lower-than-average streamflows, and very few exceeded the average condition. Very–much–below–average flows were mostly observed in the northern part of the basin. In some areas, groundwater levels were also depleted because of low recharge volumes.

Map of Murray-Darling Basin showing the deficiencies in rainfall in 2017-18.
			 The most affected areas were in the Murray-Darling Basin. Severe rainfall deficiencies (in the lowest 5 per cent) were observed across 16 per cent of the Murray-Darling Basin, and serious deficiencies (in the lowest 5 to 10 per cent) across an additional 32 per cent of the area.

The most severely affected drought areas within the Murray–Darling Basin were the Border Rivers, Gwydir, Namoi, Macquarie, Castlereagh, Darling, Paroo and Warrego catchments, all of which are in the Darling River Basin.

 



Decline in public water reserves

The combined accessible storage volume across Australia for water supply decreased due to dry conditions and extractions in 2017–18. The accessible storage volume dropped from 77 to 63 per cent of capacity during 2017–18.

Urban systems were filled to 69 per cent of capacity at the end of 2017–18; this was 6 percentage points lower than at the start of the assessment year. Due to lower–than–average inflows, the accessible storage volume was lower at the end of the year than at the start in 14 out of 19 urban supply systems.

The combined accessible storage volume of urban systems decreased in all States and Territories except Queensland during 2017–18. The combined accessible storage volume of urban systems in Queensland increased from 77 per cent of capacity to 83 per cent, mainly due to an increase in accessible storage volumes in the Townsville and Brisbane systems. The largest decrease was in New South Wales, where the combined accessible storage volume dropped from 92 per cent of capacity to 69 per cent. The Perth system, although having increased its storage volume over the year (from 25 to 37 per cent of capacity), had the lowest proportional storage volume at the end of June 2018 because of persistent dry conditions over recent years.

The combined accessible water volume in rural storages across the nation decreased from 78 to 61 per cent of capacity. Out of 40 major rural storage systems in Australia, accessible water volumes rose in five systems, remained stable in 11 and dropped in 24. There were large decreases in accessible storage volumes in the Ord system and the Murray–Darling Basin due to lower–than–average inflows in 2017–18.

Across the country, monitored groundwater levels in the upper aquifer bores were generally below average to average with most having declining or stable trends. Groundwater levels of middle and lower aquifer monitoring bores were mainly below average to average with declining trends. Compared with the 2016–17 assessment, 2017–18 recorded a higher percentage of bores across Australia with below–average status

 



Continued water trading with record number of trades

Australian water markets experienced record numbers of entitlements and allocations trades in 2017–18, highlighting the increasing role that water markets play in sustainable management across the country. The total turnover of water market trade increased significantly in 2017–18 compared to the previous year, up to around $2.4 billion. The southern Murray–Darling Basin accounted for around $1.4 billion of this total. A significant increase in allocation trades contributed to this turnover. In 2017–18, the total entitlement trade volume in Australia (1598 GL) decreased by 23 per cent compared to the previous year, but the total allocation trade volume (7527 GL) increased by 7 per cent.

In 2017–18, the total available allocation volume for the country was around 8 per cent lower than the previous year, but this was the second highest of the past eight years. The drop in allocation volume from the previous year was mainly due to reduced allocations of regulated surface water in New South Wales.

Similar volumes of surface water entitlements (around 500 GL) were traded in both the southern and northern Murray–Darling Basin, with a higher entitlement price in the southern basin than the northern. The long–term trend shows a slow increase in entitlement trade outside the Murray–Darling Basin.

The southern Murray–Darling Basin had a much larger volume of allocation trade than the northern Murray–Darling Basin, with a record high volume of water (6643 GL) traded in 2017–18. Environmental trade made up a quarter of this total allocation trade in 2017–18.

Unlike entitlement prices, allocation trade prices were generally lower in the southern Murray–Darling Basin than in the northern basin. However, allocation prices were significantly higher in the southern basin than they were in 2016–17. Limited water availability and increased demand saw upward movement on water prices during 2017–18. The high prices in some of the northern water systems, such as the Gwydir, Namoi and Macquarie–Castlereagh, reflect the response to lower rainfall amounts in those regions.

 



Increase of total water abstractions

The estimated total volume of water abstractions across Australia was 16 870 GL in 2017–18. This is 7 per cent higher than the figure reported for 2016–17.

The water abstracted for agricultural use accounted for 72 per cent of this total (12 150 GL), an increase of 9 per cent from 2016–17. Surface water abstractions for agriculture use increased by 3 per cent but groundwater extractions increased by 37 per cent compared with 2016–17. Low surface water allocations during the year in many States and Territories in response to the dry conditions resulted in farmers supplementing surface water allocations with groundwater. However, surface water remains the primary source for agriculture, contributing about 78 per cent of the total due to its easy accessibility and low abstraction cost.

About 19 per cent (3200 GL) of the total abstractions was provided for urban water supply; this was a small increase of 2 per cent. Recycled water use increased in most of the urban centres except for South East Queensland and Canberra.

Total environmental water delivered to wetlands, rivers and lakes (environmental assets) in 2017–18 from all environmental water holders and managers in the southern Murray–Darling Basin was just over 2846 GL, while the total for the northern basin was 285 GL. In the previous year, environmental water volumes delivered were 2825 GL and 565 GL in the southern and northern basins, respectively.

 



Reduced storage volumes at the start of 2018–19

In the Murray–Darling Basin, storage volumes had dropped significantly in most rural storage systems by July 2018. The dry conditions in 2017–18 meant that irrigators had used most of their carryover, resulting in relatively low volumes being carried over into 2018–19. The decreased storage volumes at the start of 2018–19, and the persistent dry climatic conditions observed across the basin since June 2018, would have influenced the water resource decisions of irrigators for 2018–19.


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