Many people have commented that Australians inhabit the world’s
driest continent, yet we are spendthrifts in how we use our water. To take
one example, 86 per cent of our water from sewage treatment still runs to
The good news is that attitudes to water are starting to change –
surprisingly quickly, actually – and this is especially promising for
agriculture and regional communities, who stand to gain most from new
water becoming available.
If we go about it intelligently, Australia need hardly be short of
water for anything. This is because a massive amount of extra water is
potentially available, simply from wise re-use of our existing water. The
total volume of recoverable water is immense, over 2000GL – enough
volume to support an urban population of 16 million people.
However to make such a ‘discovery’ reality, many things need to
happen first. Community attitudes and values towards water must continue
to change, as they have been, and we also need a coordinated approach to
solving some of the serious technical, health and economic issues that
might otherwise prevent widespread water reuse.
To give an idea how far we’ve come, before the 1990s practically all
the water in Australia was used once – then thrown away. Then the penny
started to drop – policymakers became increasingly aware of the need to
water the environment, or risk losing it, and the public began to notice
the deterioration of our rivers, coastlines and estuaries.
In 1998, we were reusing about 113 gigalitres (million kilolitres) of
water from our sewage treatment plants – or just 7 per cent of what was
flowing through them. By this year, the level of reuse has doubled to 14
per cent – and is likely to keep on climbing.
Local research and international water companies have helped bring in
new technologies for better treatment of water, so it can be safely
reused. The result has been spectacular growth in the amount of
high-quality reclaimed water available – and hence, opportunities for
Some of the highest proportions of re-use are in regional Australia:
the Albury, Goulburn and East Gippsland water utilities are already
achieving up to 100 per cent re-use.
The volumes of potentially recyclable water from most of our cities are
very large, and generally far exceed the amount the city itself is likely
to need. An estimated 1350 GL of effluent is currently lost. The amount of
stormwater is greater still, though we cannot recapture and store it all.
In total our recoverable water is likely to exceed a full Warragamba Dam
(2050GL or 4 Sydharbs) – which holds enough water to support Sydney for
This water could potentially be available for irrigated agriculture or
for the environment and become a significant "new" resource.
This water can be treated to a suitable quality for such uses and is
available year-round and can be stored in surface or underground storages
for use in dry periods.
If this extra water were to replace mains water use it would relieve
the pressure on stressed water supply catchments. Surplus water can be
piped to irrigation areas, or treated and released to restore our rivers
and wetlands, where it would generate economic growth and enhance
It is not intended we duplicate every pipe in every city, although when
it comes time to replace water pipes that may be an option. In new
subdivisions the cost of a second pipe adds only a tiny amount to the
price of each block, and is well worth considering the higher water-use
efficiency achievable for generations. Planning to leave land adjacent to
creeks will provide opportunities for future stormwater harvesting and
leave ribbons of nature within new subdivisions. In existing suburbs where
water use is concentrated for irrigation and cooling water it may be
economic for playing fields and parks and water intensive industries to
harvest stormwater and reclaimed water. At domestic scale, changes to
plumbing codes and a host of emerging new products in building supplies
will enable more efficient water use and reuse.
Having said that, plans to recycle urban stormwater, sewage effluent or
irrigation water are still sparse across the continent, and there are many
issues we first need to check out. These include issues of public health,
environmental sustainability, food quality, social acceptability,
treatment technology, monitoring, the economics of recycling and the
availability of the necessary skills.
In a nutshell, Australia still has a lot of pioneering water research
to do, the present effort is fragmented and uncoordinated and needs to be
focused nationally as well as locally.
But if it meant we could unlock a new resource on our doorstep and
build a whole lot of new industries as a result, simply by recycling our
existing water, it’d have to be worthwhile, wouldn’t it?