Squeezing more water out of our cities
The recent discovery that there might be running water on Mars is, by any estimation, quite a big deal. But it’s water on Earth that is a bigger deal for the people living here. And it will be even more so in the future.
More people means a need for more fresh water, but the water cycle doesn’t work like that: we can’t just flick the switch and change the ratio of fresh to salt water, ice and atmospheric water. We can desalinate water, at a large cost in energy, but this is neither a long term nor a sustainable solution.
As cities increase in size – and they will – they will also need water resources that can meet the increased demand. This growth, however, is taking place in the context of a changing climate, which will have an inevitable effect on water supply and availability. So we need to look at ways to manage and conserve water in a future that is likely to have higher demand for a vital resource that has diminished in supply.
This is one of the reasons a group of researchers at CSIRO have turned their attention to Australia’s cities and urban centres. In partnership with industry, governments and universities, CSIRO is researching how to help Australian urban centres plan for, respond to, and adapt to current and future major challenges. Many of these challenges, such as population growth, environment change, and resource limits are closely intertwined.
Among the institutions working with CSIRO to tackle water issues are the Goyder Institute for Water Research, the Australian Water Recycling Centre of Excellence, and the Urban Water Security Research Alliance. The projects are varied, and some are surprising.
These research partnerships are helping developers, planners and water utilities evaluate and implement sustainable water systems for cities. These include recycling of stormwater and wastewater via aquifers, stormwater harvesting and optimizing systems for environmental resilience.
“Our research into urban water improves the adaptive capacity of cities to deal with drought and water shortages, and to get the most quality out of our investments in new technologies, in terms of environmental and social benefits,” says Dr Magnus Moglia from CSIRO’s Liveable, Sustainable and Resilient Cities program.
“This is done by supporting the innovation and adoption of technology. We have found that technologically appropriate solutions can be difficult to put into practice because the human and institutional factors need to align – and that is not always the case.”
Their research program involves assessing the technical feasibility, public health, environmental sustainability and economic viability of alternative water sources. Research partners can then embed this new knowledge about risks, safety, design and operational performance in the design and governance of the water supply.
Some of the things they have found are remarkable. Rainwater tanks ought to be a water supply win, but a 2013 study found that nearly one in ten tanks had faulty automatic switches, meaning the system only drew from mains water. Thirteen percent were installed in a way that could lead to catastrophic collapse, and a quarter presented a public health risk from mosquito-borne disease, due to inadequate netting.
Another fruitful research area is in water recycling. In a decision based largely on 10 years of CSIRO research, WA’s Water Corporation has started work on Australia’s first full-scale groundwater replenishment scheme. This will guarantee as much as 20 per cent of the water supply for Perth – a city that is expected to suffer significant drying from climate change – up until 2060.
Water recycling is not universally popular, though. And this is an area CSIRO’s social psychology group is taking an interest in. Technically sound schemes have failed in the past because communities rejected them. In 2006, Toowoomba residents voted against allowing treated sewage to be added to their drinking water, in the so-called ‘Poowoomba’ poll. This was despite the city already being at Stage 6 water restrictions.
The team is currently working on using sound science to overcome consumer resistance to using recycled water in food processing – an industry that consumes a third of all the water used in Australian manufacturing.
The sort of research being done at CSIRO to future-proof Australia’s water supply is gaining international attention as other nations grapple with their own water issues.
“Australia’s urban water research has been the envy of the world, and as global water shortages and water quality problems abound both in the developed and developing worlds, many countries look to Australia for help,” says Dr Moglia.