Urban environmental efficiency: Water efficiency

2016

Urban environmental efficiency refers to how well the built environment encourages the efficient use of natural resources—land, energy and water—and the reuse and/or recovery of waste. In this section, the changing ‘efficiency’ or ‘intensity’ over time is analysed, providing some context to the Increased consumption section.

Water efficiency

A range of factors contribute to water efficiency in the built environment: water demand from both households and industry, and the use of water from various sources, including water recycling. Reflecting the trends in total water consumption in the built environment (as seen in Increased consumption), overall per-household water consumption has increased since 2010–11, whereas the manufacturing, and commercial and services industries have all experienced increased water efficiencies during this period.

Household water use efficiency

Since 2010–11, per-household water consumption nationwide has increased by 1 per cent, from 202 kilolitres per household to 204 kilolitres per household. However, the variation between states and territories during this period is large (Figure BLT43). Households in the Northern Territory and Western Australia use the most water per household (455 kilolitres and 328 kilolitres per household, respectively), compared with Tasmanian and Victorian households (173 and 162 kilolitres, respectively). Although most states and territories have shown increases in per-household water use of between 3 and 11 per cent, Tasmanian per-household water consumption dropped 48 per cent between 2010–11 and 2014–15.

In 2014–15, Australian households spent more than $5.1 billion dollars on water, paying an average of $2.99 per thousand litres (up from $2.44 per thousand litres in 2010–11) (Figure BLT44). South Australian households paid the most in Australia, at an average of $4.46 per thousand litres (ABS (2015a)). The average price paid by households for urban distributed water rose in all states and territories from 2010–11 to 2014–15. The largest increases were recorded in the Northern Territory (106 per cent—up to $3.10 per thousand litres), Tasmania (59 per cent—up to $2.78 per thousand litres) and South Australia (44 per cent) (ABS (2015a)).

Box BLT11 Water consumption from household rainwater tanks

Understanding the water use of Australian households is important for the continued management and planning of water resources. This is especially important when forecasting future household water demands.

Rainwater is an essential resource that provides a renewable supply of water, which can be used for a range of purposes, including drinking, washing, bathing, laundry and gardening. In some parts of Australia, it may be the main source of household water, whereas in others it can supplement existing mains or town water supplies. Rainwater can assist self-sufficiency and can provide a valuable alternative supply in times of drought or water restrictions.

In March 2013, 34 per cent of Australian households living in a dwelling suitable for a rainwater tank had one, compared with 3 per cent in 2010 and 24 per cent in 2007 (see Figure BLT44). The increase from 2007 to 2013 may be attributed to water restrictions, government rebate schemes, water regulations and water pricing.

Rainwater tanks were more prevalent for households residing outside capital cities (44 per cent) compared with those living in capital cities (28 per cent). Around 86 per cent of South Australian households living outside of Adelaide had a rainwater tank installed at their dwelling, followed by 56 per cent of Victorian households living outside of Melbourne. Of those households living in a state capital city, households in Brisbane and Adelaide were most likely to have a rainwater tank installed at their dwelling (47 per cent and 44 per cent, respectively), followed by households in Melbourne (31 per cent).

Water consumption from household rainwater tanks in Australia in 2013–14 was estimated to be 156 gigalitres. Areas outside capital cities have the largest consumption (109 gigalitres; 69 per cent of total consumption). Water consumption from rainwater tanks in 2013–14 was equal to 8 per cent of household water consumption (1906 gigalitres). Queensland had the highest estimated consumption of water sourced from household rainwater tanks, at 46 gigalitres (29 per cent of Australia’s total consumption from rainwater tanks). Queensland also had the largest tank storage capacity (9 gigalitres) of all the states and territories (Figure BLT45).

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Water tank, Canberra backyard
Photo by Anthony Michelle McAulay

Industrial water use efficiency

In contrast to the residential sector, business and industry associated with the built environment improved their water efficiency between 2010–11 and 2014–15 (Figure BLT46). Commercial and services industries (including transport and construction) increased their IGVA per gigalitre of water used by 26 per cent between 2010–11 and 2014–15. Manufacturing businesses increased their IGVA per gigalitre of water used by nearly 4 per cent during the same period (ABS (2015a)).

Coleman S (2016). Built environment: Urban environmental efficiency: Water efficiency. In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/theme/built-environment/topic/2016/urban-environmental-efficiency-water-efficiency, DOI 10.4226/94/58b65a5037ed8