How much water do we use?
South Australia uses just over 1,000 GL of water per year, which is an average of about 600–700 kL per person. Figure 32 shows water use by sector for South Australia during 2015–16.
Agriculture uses the most water, which amounts to about three quarters. This amount fluctuates year by year. For example, agricultural water use in 2015–2016 was just under 860 GL (86%), an average of 4.1 ML/ha. This was almost 100 GL more than the previous year’s use of 771 GL. This reflects the variations in short-term climatic conditions and produce markets.
The average water use varies widely depending on crop types – from less than 1 ML/ha for wheat, oats and maize, to more than 9 ML/ha for fruits and nuts.
Water use for manufacturing fell from 88 GL (8%) in 2008–09 to 49 GL (4.5%) in 2015–16.
The mining industry’s use over the last 10 years has varied between 25 and 46 GL per year.
Our use per household, for domestic use only, is about 200 kL per year, or 135 GL in total.
Parklands, open spaces, sporting grounds, places of worship and gardens account for about 17% of our urban water use. This comes from a mix of mains water, groundwater, stormwater, recycled wastewater, rainwater and surface water.
Conversions for kilolitres, megalitres and gigalitres
1 kL is 1,000 litres. In volume, it represents 1 m3 and 1 kL of water, and weighs 1 tonne. Kilolitres are the units most commonly used in referring to household water consumption, with the average Adelaide household using about 200 kL each year.
1 ML is 1,000 kL or 1 million litres, and is roughly the volume of most 50-metre public swimming pools. The Torrens Lake, between Hackney Road and the Torrens Lake weir, holds about 600 ML.
1 GL is 1,000 ML or 1 billion litres, and represents a volume of water 1 km2 by 1 m deep. When full, Hope Valley Reservoir holds about 2.8 GL and Happy Valley Reservoir holds 11 GL.