Squeezing more water out of our cities

By Virginia Tressider October 30th, 2015

More people in our cities means a need for more fresh water. Scientists in Australia are turning their attention to the water supply challenge and coming up with some innovative solutions.
Water rushing through a storm drain

As cities and populations grow, we’ll need to get smarter with how we use our water. Image: Tom Hamilton/Flickr

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.

A rainwater tank in back courtyard of a house

The domestic rainwater tank is a common sight in Australia, but they need to be maintained to be effective and safe.

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.

More information on water for cities

1 comments

  1. Having grown up inland where drinking water was pumped out of the river above the town (Wellington, NSW) and treated effluent discharged into the river, I have no problem with the concept of reclaimed water from what-ever its source. Every town along the Macquarie River handled water in the same way as I experienced at Wellington. In effect all town were drinking reclaimed water. TYhe politicians who were reponsible for the extravagently expensive desalination plnat in Sydney, who justified it by saying people weren’t prepared to drink effluent, needed to modify their emotive languagfe and look what was already happening within our state. Even with the probably basic treatment of effluent during the 50s and 60s when I lived in Wellington there were problems with water borne diseases (from the town river sourced drinking water). The politicians need to have a good hard look at reclaiming potable water from sewerage as I believe it is a far more energy efficient process than desalination.

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