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Changes in water consumption Author: Phil Krasnostein 18 August 2011
Tags: Design Trends, Case Studies, Climate Change / Sustainability, Gray Water / Black Water, Innovation, Research & Knowledge, Water Harvesting, Water Quality, Australasia Page 1 of 2 | Single page
How urbanisation is changing water consumption and distribution and a new way to combat the problem of dissipating water resources.

It is predicted major urban centres in Australia will have an additional demand of over 600 billion litres of water annually and by 2056 of over 1000 billion litres. The unstoppable trend of urbanisation means for the first time in history more than half of the world’s population are living in towns and cities.

Our urbanised lifestyle is putting a significant strain on our water resources. The 2009 United Nations’ World Water Development Report predicted nearly two-thirds of the world will face water shortages by 2025 displacing anywhere from 24 to 700 million people.

The combined effects of increasing urban populations, lack of investment in water infrastructure and shifting rainfall patterns are causing increasing stress on drinking water supplies across the globe, including capital and regional centres in Australia.

Seventy per cent of the earth’s surface is made up of water, yet only 2.5 per cent of the world’s water is fresh.

With increasing numbers of people wanting to implement sustainability strategies, there are opportunities to reduce the cost of supplying ‘new’ water, while providing plentiful supplies of high quality water for irrigation, home, business and landscape use.

These opportunities present alternative water supplies from non-traditional sources such as bores, rivers, rainwater, stormwater, seawater, greywater and black water. To make use of these alternatives requires a shift from the traditional model of large centralised water treatment plants built and operated by water authorities or municipalities. This shift is gathering pace and has led to a proliferation of what has become known as ‘distributed systems’.

A distributed system can either be dedicated to delivering water to a single community (e.g. a home, apartment building or university campus), or can be part of a linked group of such systems operating together to create a network.

Distributed systems vs. traditional systems
Distributed systems have a number of benefits over the traditional centralised model. They can:
• Reduce costs – systems can be smaller, simpler and custom built
• Be designed to meet local requirements – they can be optimised to take advantage of specific circumstances such as the use of waste energy to operate the plants, or available local uses for waste sludge
• Improve service security and risk management – a network of linked distributed systems provides supply options in the event of failure of an individual treatment plant
• Maintain gardens and landscapes in times of water restrictions – having local recycling systems can drought proof communities.

Not all water we use has to be potable
One of the best ways to improve the sustainable use of water is to recognise that not all of the traditional uses of drinking water actually require drinking water. Good examples are irrigation, toilet flushing, laundries and vehicle washing.

However, any use of water requires it to be of a quality appropriate to a particular use, known as ‘fit for purpose’.

Understanding the performance and approvals required by the various states and local councils around Australia is critical as there is an increasing level of scrutiny by regulators and a consequential tightening of the rules governing the use of water from alternate sources. Regulators are, therefore, increasingly placing higher demands on the systems used to treat water and on the operators of the systems.

Although regulations vary from state to state there are some underlying concerns that need to be addressed:
• Systems have to produce high quality water
• Systems have to be reliable
• Owners and regulators need to be able to ensure they are delivering the required quality
• Systems have to be easy to manage and maintain.

To respond to these requirements, new and innovative approaches to traditional water treatment problems need to be developed.

Continued...



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