Australia is the driest inhabited continent in the world. 80% of the country receives less than 600mm of rain every year2, it has the least amount of water in rivers, and the smallest area of permanent wetlands3. The vast majority of our glorious country is red, scorching hot, and drier than a bucket of sawdust.
With water such a scarce resource, how do Australia’s 25 million residents remain upright? Where does water come from in Australia? In this article, we’ll explore the various water sources that keep Australians fed, quenched, and washed.
Surface water is water found above ground, including rivers, streams, lakes, and reservoirs. Despite having some of the lower river levels in the world, about 95% of Australia’s water comes from these sources, with NSW using the biggest portion (3.5 million millilitres), and ACT using the smallest (46,625 millilitres), although this doesn’t account for differences in population.
Our dependence on scarce surface water has led to investment in desalination and recycling infrastructure (more on this below), which will help us fight worsening drought due to climate change, and to keep up with demand.
Rivers and streams
Most Australian rivers and streams don’t have flowing water in them, even in the tropics, but we still extract a lot of water from them. In Sydney, most of their drinking water comes from the Blue Mountains and Southern Highlands4, which flow into the Hawkesbury-Nepean River system. Most of Melbourne’s water is sourced from the forests in the Yarra Ranges and Central Highlands, which have rivers and streams running through them5.
The biggest river system in Australia is in the Murray-Darling River basin, which has around 75% of its water taken for farming5, and accounts for a whopping 50% of Australia’s total water usage6.
In most parts of Australia, reservoirs are the main source of municipal water. Unfortunately, reservoirs are dependent on rainfall, making them unreliable in long periods of drought7, prompting various conservation measures from local governments.
About 50% of Brisbane’s water comes from the Wivenhoe Dam west of the city, a large portion of Adelaide’s water comes from various reservoirs that flow out of the Murray-Darling River basin, and between 10% to 20% of Perth’s water comes from reservoirs near the city.
Groundwater is water found in soil and rock below the earth’s surface. Around 4% of Australia’s water comes from this source, with most of it used by Perth and Adelaide. In Perth, groundwater accounts for around 40% of their total supply, with most of it coming from the Gnangara groundwater system that covers a huge area of Perth and land to its north. For Adelaide, 41% of its water comes from groundwater, taken from underground water bodies known as aquifers that are dotted throughout the Murray-Darling River Basin.
Australia’s other major cities use groundwater from the Daly Basin in the Northern Territory, the Otway Basin in South Australia, and the Great Artesian Basin in Queensland. But most of the water from these cities comes from rivers, streams, and reservoirs.
Groundwater is more stagnant than water from rivers and reservoirs, and much more likely to contain harmful bacteria. As a result, groundwater needs more treatment to be safe for human usage. Australia has around 268 water treatment plants that handle over 50 megalitres per year1 (the equivalent of around 300,000 bathtubs of water), which process groundwater, wastewater, seawater, and other types of water.
Australia is the driest continent on earth and also one of the world’s highest consumers of water, which makes recycling a critical part of its water strategy. A big part of this is recycling grey and black wastewater that comes from toilets, baths, showers, and appliances that use water, which must be processed by one of Australia’s many wastewater plants.
Brisbane and Adelaide are leading the pack with wastewater recycling, already adding it back into their reservoirs for reuse. The Western Australia Water Corporation in Perth is also in the process of constructing a large wastewater recycling plant, which will provide a huge amount of recycled water for western Australians6.
Non-potable recycled wastewater that has been used to irrigate public parks, golf courses, crops, and other non-drinking uses can be reused without having to be treated again, which makes it an incredibly sustainable source of water. Western Australia are the best at reusing this kind of water, reclaiming almost 30% from their sewage and putting it to good use.
Oceans make up 70% of our planet—an abundance of water that becomes a reliable source for Australians, provided we can remove the salt from it. Thankfully, there are large desalination plants in Perth, Binningup (WA), Adelaide, Sydney, Dalyston (Victoria), and the Gold Coast8, which can remove the salt, bacteria, and pollution from seawater and make it usable.
The two plants in Western Australia and the plant in Adelaide are particularly important, where traditional water sources are becoming scarce1. In fact, around 40% of Perth’s entire water source comes from its two desalination plants, which help to protect it against severe droughts, which are becoming all the more common due to global warming.
Seawater and desalination plants are considered to be an important part of Australia’s future water supply.
Australia has a number of water sources that it can draw on, but at the moment, the sources that we mostly depend on (rivers, streams, and reservoirs) aren’t sustainable. This is why the Australian Government is investing heavily in recycling and desalination plants, to ensure that every Australian citizen and business has access to the water they need to survive and grow. As the driest continent in the world, this couldn’t be a more important step forward for the country.
- Amgad Elmahdi, 2015, The role of water in Australia’s uncertain future, The Conversation
- Kate Doyle, 2018, What you need to know about droughts: Why they happen and how they are defined, ABC News
- Brian J Preston, 2009, WATER AND ECOLOGICALLY SUSTAINABLE DEVELOPMENT IN THE COURTS, NSW Government
- Water sources, Sydney Water
- River Murray, Government of South Australia
- Water supply and sanitation in Australia, Wikipedia
- 2011, Australia’s water resources and use | Australia State of the Environment Report, Australian Government
- List of desalination plants in Australia, Wikipedia