In the guide below, we provide a summary of water supplies and resources in Australia (on both a national, and also regional level)
It’s important to point out that the information in this guide is mainly paraphrased from, or based on the BOM 2016-17 report (where direct text is used, we use quotations).
We’ve identified where information comes from another source, such as some stats and info from the ABS for example.
We’ve also made some of our own commentary too.
You can access the BOM report, and other reports and sources, in full (and cross check the information provided below), by using the links provided in the ‘Sources’ list at the bottom of this post.
Australia’s Climate & Rainfall
Climate and rainfall are an important consideration to any country’s water supplies and resources
This is because of how climate and rainfall affect the hydrological cycle, as well as inflows and recharge rates of natural water sources
Climate In Australia
Australia has a highly variable climate i.e. the climate differs across the country
Rainfall In Australia
Australia is the world’s second driest continent in terms of rainfall (after only Antarctica), with low annual mean rainfall
Australia also has high rainfall variability across the different regions of the country
From abs.gov.au: ‘Australia’s average (mean) annual rainfall [is] below 600 millimetres (mm) [for] over 80% of the continent, and below 300 mm [for] over 50% [of the continent]’
Australia’s long term mean rainfall is 461 mm … (bom.gov.au)
Trends In Rainfall
Average annual rainfall has increased in Australia over the last century, but specific regions have experienced a substantial decrease since 1960
Australia’s average annual rainfall (measured in 10 year periods) has … increased from 1900, to 2010. 1900 to 1910 rainfall was 429mm, whilst 2000 to 2010 rainfall was 486mm
However, since 1960, there have been substantial decreases in rainfall over three relatively small, but economically and agriculturally important, regions [which abs.gov.au lists]
Natural Events, & How They Temporarily Impact Rainfall
Australia has also experienced natural events like the ‘Millennium Drought’ over it’s history, that have impacted rainfall levels in certain regions over certain time periods
More Information About Australia’s Climate
You can read more about national and local climate, and changes in the various climates over time in the abs.gov.au report
Water Storage Capacity, & Water Usage In Australia
Water Storage Capacity, & Accessible Storage Volume In Australia
Of Australia’s total accessible public storage capacity, on a certain % of storage volume is accessible
Australia [has a] total accessible public storage capacity [of] just over 80,000 GL.
The accessible storage volume for direct water supply purposes at the beginning of 2016–17 was at 57 per cent of capacity … this increased by 20 percentage points to 77 per cent of capacity by the end of 2016–17
Consumptive vs Non Consumptive Water Use
Most of Australia’s water use might be non consumptive according to abs.gov.au
During 2015-16, an estimated 76,544 gigalitres (GL) of water was extracted from the environment to support the Australian economy.
A total of 60,702 gigalitres of the total 76,544 gigalitres … was used in-stream (for example hydro-electricity generation) and is a non-consumptive use of water.
Total consumptive use of water … was 16,132 gigalitres.
What Accessible Public Water Supplies Are Used For
Of the accessible water storage in Australia, a significant amount goes to both large hydro-electric power generation schemes (which may or may not be able to be re-used), and agriculture
Australia [has a] total accessible public storage capacity [of] just over 80,000 GL.
Around 36 per cent is part of … large hydro-electric power generation schemes
[Australia’s remaining water supplies are allocated 70% to agriculture, 20% to urban water supply, and 10% to other industries (such as mining, manufacturing, electricity and gas supply), and other uses (such as environmental water releases, cultural use, small scale hydro electric power generation, and flood mitigation)]
Water Stress In Australia
On a national level, Australia may not generally be considered a water stressed country
Australia is not a water stressed country according to the UN’s global initial water stress indicator, and, Australia’s low population density gives it high per capita water resources
However, certain regions in Australia may have experienced water stress and water scarcity issues in the past. Perth is one city in Australia that has had to use different solutions to address their water scarcity issues
Additionally, some groundwater bore results show a recent declining groundwater level trend in some regions of Australia
How Australia Rates According To The UN’s Global Initial Water Stress Indicator
Australia’s recent annual water stress indicator numbers are far below the UN’s global indicator of initial water stress – meaning Australia is currently not a water stressed nation
Australia’s Per Capita Renewable Resources
Based on Australia’s long-term average rainfall, and the % of rainfall that recharges surface water and ground water sources, bom.gov.au indicates that: ‘… the long-term average per capita renewable water resource for Australia is 43 kL/day …’
Australia is considered to have high per capita water resources, because although the total volume of fresh water available in Australia is less than in many other countries, Australia also has a low population density
Groundwater Levels Over Time
The five-year trends in upper aquifer groundwater levels [across Australia] were mostly declining (51 per cent) or stable (39 per cent). Only 9 per cent of upper aquifer bores showed a rising trend.
Similarly, groundwater levels of middle and lower aquifer bores were mainly below average to average with declining trends.
[However, thousands of groundwater bore tests in 2016-17 might show a recent trend towards rising groundwater levels – although, groundwater levels differ between regions across Australia]
Other Potential Water Issues In Australia
Some of the other water issues Australia might deal with might include:
– The distribution of water resources is uneven across Australia
bom.gov.au indicates that: ‘… there’s ‘abundant water resources in the northern regions compared with the middle part of the continent.’
– There’s streamflow and ground water salinity, as well as salinity in soils
This can be caused by a range of factors, and impacts how much water is suitable for use or suitable for drinking (with or without treatment)
bom.gov.au indicates that: ‘About 60 per cent of Australia’s river and stream sites analysed in 2016–17 … were considered suitable for drinking’
– There’s been a recent reduction in streamflow in some regions of Australia
Reduction in streamflow is the catchment’s response to rainfall
From bom.gov.aus: ‘These changes [in Australia] could arise from the decoupling of groundwater and surface water, and changes in land use [and] A detailed analysis of catchment rainfall runoff processes is needed to understand the causes of this decline.’
– Only a certain % of rainfall becomes inflow for surface water or recharge for groundwater
Something that is worth noting about ‘renewable water resources’, is that only a certain % of rainfall might recharge surface water and groundwater sources.
bom.gov.au for example notes that in Australia: ‘… only a small portion of [total rainfall] becomes renewable resources. On average, 9 per cent of this rainfall becomes runoff and about 2 per cent becomes recharge to groundwater’
– There’s generally low or average levels of ground water volume
– Slow recharge rates of ground water
Meaningful changes usually take 5 years or more
– Water storage volume in ground water aquifers or bores doesn’t always increase after rainfall, whereas surface water generally does
– Rainfall variability impacts water availability
bom.gov.au: ‘Large year-to-year rainfall variability, including seasonality, affects water availability in the Murray–Darling Basin [and] This high spatial and temporal variability in water distribution makes the water difficult to use’
– Groundwater can be more expensive to access than surface water
From bom.gov.au: ‘With higher rainfall and easier access to surface water, farmers rely less on groundwater, which usually is more expensive to access.’
This isn’t necessarily a problem, but is a consideration
How Australia Is Addressing Some Of It’s Water Issues
To improve water security and reduce water risk for Australia’s water supply, and because of a changing climate and growing population, climate-resilient sources such as water desalination and water recycling have been introduced in some parts of Australia
Perth also has it’s own ground water replenishment scheme that helps recharge aquifers – wastewater is treated, filtered through natural sands, and injected/stored in aquifers, where it mixes with groundwater, and can be used at a later date with further treatment
Main Water Sources In Australia
On a national level, most of Australia’s water supply in urban areas might come from surface water. Traditionally, Australian cities have relied on surface or groundwater sources to meet their water needs.
On a State, Territory and city level, different water sources might make up different %’s of the water supply, depending on the geographic location
Perth is an exception to many other cities, as desalination is a prominent water source there
Australia has two main water supply systems overall – the Murray Darling Basin supply system, and the Northern supply system.
List Of Water Sources In Australia
The main water sources in Australia consist of:
– Surface Water
– Ground Water (according to bom.gov.au: ‘In Australia [the volume of groundwater to surface water is likely to be higher than the global average of groundwater volume being 13 times higher] given the arid nature of much of the continent])
– Seawater Desalination
– Recycled Water
– Interregional Transfers & Trades (the buying and selling of water entitlements and allocations within states, and between states – also known as water trading on the water market)
bom.gov.au indicates that ‘… cities mostly rely on ground water and surface water … [with] One-fifth to one-third of the water used in Australia comes from groundwater’
State, Territory & City Level
According to bom.gov.au (paraphrased):
You can see a full graph of water sources by city on page 51 of the BOM report, but in 2016/17, this is how the major urban areas in Australia sourced their water:
Sydney – surface water made up a large majority of total water use, with recycled water only making up about 6%
Melbourne – surface water made up a large majority of total water use, with interregional transfers, desalinated water, and recycled water making up the rest
South East Queensland – surface water made up a very large majority of total water use (97%), with recycled water, groundwater, and desalinated water making up the rest
Perth – desalinated water made up majority of total water use, along with groundwater, and recycled water and surface water made up the rest
Adelaide – surface water made up a very large majority of total water use (at 87%), with interregional transfers, recycled water and desalinated water making up the rest
Canberra – surface water made up a large majority of total water use, with recycled water making up the rest (at only about 9% of total water use)
theconversation.com has a guide that shows what water sources Australia’s major cities currently get their water supply from
Perth in Western Australia is an example of a city that currently gets most of their water from desalination, followed by groundwater.
Climate Independent Water Sources
Australia uses two main climate independent water sources – desalination, and water recycling
Perth is one city in Australia that climate independent water sources in the form of desalination and water recycling
2. https://www.abs.gov.au/ausstats/[email protected]/Lookup/by%20Subject/1301.0~2012~Main%20Features~Australia’s%20climate~143