What’s in the pipeline for water supply?

by Paul Angus
0 comment

The Australian millennium drought effectively ended the age of ‘water entitlement’, shining a spotlight on the need to conserve water. This led to a renewed focus on integrated water management, water recycling and a better approach to water-sensitive urban design. However, our cities are not immune to problems with water supply, so what’s next in the pipeline? PAUL ANGUS explains.

Why do we often take for granted the very things that deserve our gratitude the most, assuming they will be there whenever we need them? This applies to our sense of entitlement to water. Having wholesome water on demand is one such luxury we take for granted; however, we should never forget that water is a precious commodity. Price determination depends equally on demand and supply, which will further rise, as water scarcity and population numbers increases.

COUNTING DOWN TO ZERO

You’ve probably never given it a second thought, but how often do you brush your teeth and leave the water running from the tap? Perhaps you shower for a longer period than you actually really need? Do you regularly check your water bill to see how much you are actually using and modify your behaviour to reduce your consumption? Hold on to that thought for a second, and then consider that, according to the United Nations, there will not be enough water to sustain the world’s population by the year 2040. This has already motivated many building owners and facility managers to do everything they can to minimise water usage and save the resource, wherever possible, within their asset.

Many people do not understand or care about the scarcity and vulnerability of our precious water resource. However, recent events in Cape Town have shown the dangers of water scarcity, and it faces the prospect of being the first major city in the modern era to face the threat of running out of drinking water. For the estimated population of 3.78 million, the inevitable ‘Day Zero’ predicted in the next few months will result in the water supply being completely depleted. Like many growing cities around the world, Cape Town has experienced increasing population growth; however, uncontrollable circumstances including a record drought – perhaps intensified by climate change – are sparking one of the world’s most dramatic urban water disasters.

LONDON CALLING

Of all the cities in the world, London is one that springs to mind when discussing a water shortage. With more than eight million inhabitants and an average annual rainfall of about 600 millimetres (less than Paris’ average and only about half that of New York), London relies on and draws 80 percent of its water from rivers (the Thames and Lea). According to the Greater London Authority, the city is pushing close to capacity and is likely to have supply problems as early as 2025, predicting “serious shortages” by 2040.

WATER, WATER, EVERYWHERE?

So what is the situation like here in Australia? Across the seas, east of Cape Town, several Australian cities are watching events affecting their South African counterpart nervously. Despite covering almost 70 percent of the Earth’s surface, water, especially wholesome drinking water, is not as plentiful as you may think. Only three percent of it is fresh water and it is not spread equitably among the countries or people around the world, with some having water far in excess of their needs and others already facing water scarcity. Meanwhile, global demand for wholesome water will exceed supply by 40 percent in a little over a decade – as early as 2030 – thanks to a combination of population growth, human action and climate change.

Over the last several years, Australia has been faced with a similar dire water crisis, which is threatening communities across the country. Many of the same issues that affect Cape Town also plague Perth and Adelaide, with the New South Wales Central Coast, Goulburn and Broken Hill not lagging far behind, with worryingly little water to supply ever-increasing populations. These isolated locations within the world’s driest continent face mounting challenges in providing fresh water to their residents. The vast majority of Perth’s water originates from underground aquifers, plus from two huge – and costly – desalination plants, which provide the city with approximately a third of its water.

The notion that Australia’s largest city, Sydney, could potentially run out of water led to the construction of a desalination plant that can potentially produce up to 50 million litres of water each day, equating to 15 percent of Sydney’s water requirements. However, the millennium drought ended, and rainwater replenished an array of water reservoirs and dams providing the city’s water supply. As a result, the desalination plant was placed into maintenance mode just a few years later, mothballed but ready to spring into action when necessary.

According to the Australian Bureau of Statistics, Sydney is Australia’s most populated city, with an estimated population of over five million people. Sydney currently uses approximately 33.7 billion litres of water per year and, as it grows, the demand for water will increase. In a little over a decade, based on anticipated population growth, the demand for water is expected to grow by 30 percent, to 44 billion litres by 2030.

Although alarming as all of the above is to hear, as a facility manager, how do the risks of water scarcity affect the management and value of your asset? The supply of water is often not seen as a high business risk, based on its relatively low cost at present. However, risk lies in the security of supply, which is paramount to the continuity of a business. In a building, if water supply is cut for any given reason, for a significant period of time, the building becomes uninhabitable and unproductive and, as such, a loss of earnings will be incurred. In order to build confidence and value, and remain attractive for tenants and investors alike, it is paramount to ensure a self-sufficient water strategy is in place.

© 123RF's Chayatorn Laorattanavech © 123RF

© 123RF’s Chayatorn Laorattanavech © 123RF.com

DON’T LOSE IT, REUSE IT

Population growth plus the desire to live closer to the workplace is resulting in urban growth in the form of high-rise towers, which is having an adverse effect on our cities’ ageing water-supply infrastructure. Increased accommodation and rental costs are driving unprecedented growth in the inner ring and suburbs of Australian cities. Accommodating more people in established areas takes advantage of existing infrastructure, but also presents capacity and physical challenges and constraints. Infrastructure planning at a precinct scale can be highly responsive to the broader development aspirations, while creating opportunities for more flexible, innovative and integrated responses through planning at a finer grain than traditional centralised approaches.

We are already preparing our assets to face the water shortage challenges of tomorrow by embracing advanced technologies, including integrated water management, water recycling and water- sensitive urban design approach. However, what more can and should we be doing now?

Let’s embrace the digital revolution to count every drop. Measuring what we use by gathering data – the right data – through smart water networks assists in understanding where and exactly how water is being used, creating a strategy to review usage patterns and to reduce water consumption.

On-site water systems collect and treat non-potable water, which can include wastewater, stormwater, rainwater and more. This water can then be reused in a building for non-drinking water requirements, such as irrigation, toilet flushing and mechanical cooling requirements. However, by using alternative water sources for these needs, reusing on-site water systems reduces

the waste of valuable, wholesome drinking water. In fact, water reuse can account for up to 50 to 95 percent of the water used in residential or commercial buildings. On the flip side, water storage and treatment takes up valuable space, which results in the loss of potential revenue. So what is the solution?

NOT JUST A PIPE DREAM

The Sydney Water and Better Buildings Partnership masterplan is for over 50 percent of Sydney’s water demand in 2030 to be supplied by recycled water, direct from a decentralised infrastructure supply. However, the city’s existing building assets will need to be ready to connect to this network when it becomes available. So what do we need to do for our existing assets?

First, we should consider the practical need for building owners and facilities managers to identify if the upgrade of assets for recycled water is financially sound. Second, an off-site recycled water scheme would be designed to supply non-potable water of a quality that is fit for purpose for use in cooling towers, toilet flushing and irrigation, without requiring the need to change the existing cooling tower, toilet and urinals.

Finally, the cost of connecting an existing building to a recycled water network is reduced by undertaking the required plumbing upgrades incrementally, during planned building refurbishment. The capability to connect to recycled water can be built into the retrofit scope
in advance of the recycled water scheme’s completion. Furthermore, new buildings can be intelligently designed to incorporate the necessary pipework reticulation to connect to the recycled supply. As soon as the infrastructure network is available, recycled water can be connected to the building asset from an off-site scheme.

From office buildings to conference centres to eco-district developments, whatever the asset, decentralised recycled water systems will effectively change the way buildings, districts and entire communities use, and reuse, water, now and for future generations. Few cities around the world are as connected to water as Sydney, yet the city is not immune to problems with water supply.

AECOM’s recent Sydney Manifesto report encourages us to create a water- sensitive city. Download the report today at http://bit.ly/2HtjUxc and see what you can do to make sure every drop counts. ●

Paul Angus is an associate director – Hydraulic Services at AECOM, based in Sydney. He specialises in providing a sustainable approach to system design, including water conservation, recycling and generating innovative engineering solutions.

This article also appears in the August/September issue of Facility Management magazine.

Lead image: 123RF’s Tanawat Pontchour © 123RF.com

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More