For green cities to become mainstream, we need to learn from local success stories and scale up



Melbourne has a rich legacy of urban parks thanks to planning decisions made when the city was first established.
Shutterstock

Jason Alexandra, RMIT University

Greening our cities has become one of the great global imperatives of the 21st century including to tackle climate change. And Australia’s sprawling car-based cities are gradually changing to embrace green or living infrastructure.

Green cities bring together elements of architectural design and urban planning, often combining plants and built infrastructure to meet the needs of humans, such as our love of nature.




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Australian cities are lagging behind in greening up their buildings


Trees, plants, waterways and wetlands can deliver climate conditioning, cooling cities by reducing the urban heat island effect. They also absorb carbon dioxide, filter wastewater and create habitats.

Living elements can be incorporated with built infrastructure at a range of scales, from individual buildings with green walls and roofs, through to citywide strategies. And there are a suite of strategies to guide more widespread integration of biological elements and ecological processes in cities.

In recent months, we profiled Australian examples of living infrastructure that show some of Australia’s approaches to developing green infrastructure, from greening Melbourne’s laneways to Canberra’s urban forest. These cities are already redesigning their water systems and implementing urban forest strategies to create green belts and protect and restore waterways.

Melbourne and Canberra provide some useful examples of the green cities movement, but to make it mainstream, these techniques need to be adopted widely through policies supporting more holistic and better integrated urban planning.

Why we need urban forests

Percival Alfred Yeoman was one of the first Australian pioneers of urban forestry. In 1971, he articulated a clear vision for enhancing cities with trees.




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Local governments in Adelaide, Brisbane, Melbourne and Sydney, are implementing his ideas, committing to ambitious increases in urban canopy cover. Their targets range from 25% to 40%.

This revived interest in urban forestry comes from its well documented potential for accelerating the transition to more climate adaptive cities.

The social, environmental and economic benefits of urban trees, or “ecosystem services”, are becoming better recognised, including for their recreational and cultural values.

Melbourne and Canberra are leading Australia’s green cities movement

Melbourne

Melbourne has a rich legacy of urban parks and green belts thanks to planning decisions made in the city’s early years.




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Urban greening can save species, cool warming cities, and make us happy


These parks underpin a new wave of urban greening, with projects that aim to deliver action on climate change, biodiversity and the health and well-being of communities.

The Melbourne green infrastructure plan includes:

  • a “growing green guide” that provides practical advice to community and business groups on planning, design and maintenance of green infrastructure

  • the greening laneways strategy, which builds on the commercial revitalisation of Melbourne’s laneways over three decades. Laneways with greening potential were mapped and demonstration project developed to display techniques for making them more vibrant green spaces for business, tourists and locals to enjoy

  • an urban forest strategy, with an overall target of 40% canopy cover by 2040. And 5 to 8 million trees will be planted over coming decades for the greater Melbourne metropolis.

Canberra

Canberra is often described as “a city within a landscape” and the “bush capital”. But its higher altitude, hot dry summers and cold winters bring a set of challenges for green infrastructure.

With more than 800,000 planted trees, Canberra is an urban forest. But these trees require special care and attention given they are ageing and suffering from a hotter, drier climate.




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How do we save ageing Australians from the heat? Greening our cities is a good start


Wildfire also represents a significant risk where urban and rural areas connect. This means Canberra needs urban forests that will cool the city in warmer months without also escalating wildfire risks.

The ACT Government has committed to action on climate change, legislating targets for 100% renewable electricity by 2020 and carbon neutrality (no net carbon emissions) by 2045.

With more than 800,000 trees, Canberra is an urban forest.
Shutterstock

Integrated approach needed to expand green cities

Greening cities requires a holistic approach – for instance, not leaving the health of waterways entirely to water engineers.

Greening cities is more than just a technical challenge. Transforming the form and functions of urban systems, through urban forests and other living infrastructure, requires greater leadership and political commitment, integrated planning and community participation, and long-term thinking.

An integrated approach to greening cities involves mapping diverse opportunities and mobilising support for change in the community. As an example, urban storm water can be a productive resource when used in constructed wetlands or to irrigate urban forests.

The vertical gardens in One Central Park in Sydney are globally renowned for their green infrastructure.
Shutterstock

And often urban drainage lines and wastelands can be transformed into green spaces, but it’s worth recognising there is intense competition for space for housing.

But for more widespread adoption of integration, institutional support within local governments and metropolitan water and planning agencies is needed.

So to scale up living infrastructure in our urban landscapes, we must learn from local success stories, conduct more research, and better understand how to deal with climate adaptation and mitigation challenges.




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If planners understand it’s cool to green cities, what’s stopping them?


Jason Alexandra would like to gratefully acknowledge the contributions of Barbara Norman to this article.The Conversation

Jason Alexandra, PhD candidate, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The 39 endangered species in Melbourne, Sydney, Adelaide and other Australian cities



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Threatened species live in cities and towns around Australia, including the critically endangered western swamp tortoise.
Elia Purtle, AAP Image/Perth Zoo

Kylie Soanes, University of Melbourne and Pia Lentini

The phrase “urban jungle” gets thrown around a lot, but we don’t usually think of cities as places where rare or threatened species live.

Our research, published today in Frontiers in Ecology and the Environment, shows some of Australia’s most endangered plants and animals live entirely within cities and towns.

Stuck in the city with you

Australia is home to 39 urban-restricted threatened species, from giant gum trees, to ornate orchids, wonderful wattles, and even a tortoise. Many of these species are critically endangered, right on the brink of extinction. And cities are our last chance to preserve them within their natural range.


Credit: Elia Purtle

Urban environments offer a golden opportunity to preserve species under threat and engage people with nature. But that means we might need to think a little differently about how and where we do conservation, embrace the weird and wonderful spaces that these species call home, and involve urban communities in the process.

Roads to the left of them, houses to the right

When you picture city animals you might think of pigeons, sparrows or rats that like to hang out with humans, or the flying foxes and parrots that are attracted to our flowering gardens.

But that’s not the case here. The threatened species identified in our research didn’t choose the city life, the city life chose them. They’re living where they’ve always lived. As urban areas expand, it just so happens that we now live there too.

The first hurdle that springs to mind when it comes to keeping nature in cities is space: there’s not a lot of it, and it’s quickly disappearing. For example, the magnificent Caley’s Grevillea has lost more than 85% of its habitat in Sydney to urban growth, and many of its remaining haunts are earmarked for future development. Around half of the urban-restricted species on our list are in the same predicament.

It’s especially tough to protect land for conservation in urban environments, where development potential means high competition for valuable land. So when protected land is a luxury that few species can afford, we need to work out other ways to look after species in the city.

Caley’s grevillea has lost 85% of its habitat as Sydney has expanded.
Isaac Mammott

Not living where you’d expect

Precious endangered species aren’t all tucked away in national parks and conservation reserves. These little battlers are more often found hiding in plain sight, amid the urban hustle and bustle.

Our research found them living along railway lines and roadsides, sewerage treatment plants and cemeteries, schools, airports, and even a hospital garden. While these aren’t the typical places you’d expect to find threatened species, they’re fantastic opportunities for conservation.

The spiked rice flower is a great example. Its largest population is on a golf course in New South Wales, where local managers work to enhance its habitat between the greens, and raise awareness among residents and local golfers. These kinds of good partnerships between local landowners and conservation can find “win-win” situations that benefit people and nature.




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A series of unfortunate events

It’s no secret that living in the ‘burbs can be risky: a fact best illustrated in the cautionary tale of a roadside population of the endangered Angus’s onion orchid. Construction workers once unwittingly dumped ten tonnes of sand over the patch in the late 1980s, then quickly attempted to fix the problem using a bulldozer and a high-pressure hose. Later, a portaloo was plonked on top of it.

Examples like this show just how important it is for policy makers, land managers and the community to know that these species are there in the first place, and are aware that even scrappy-looking habitats can be important to their survival. Otherwise, species are just one stroke of bad luck away from extinction.

People power

It’s common to think if you want to conserve nature, you need to get as far away from people as you can. After all, we can be a dangerous lot (just ask Angus’s onion orchid). But we also have extraordinary potential to create positive change – and it’s much easier for us to do this if we only have to travel as far as our backyard or a local park.

Many urban-restricted species get support by their local communities. Examples from our research showed communities across Melbourne raising thousands of dollars in conservation crowdfunding, dedicating countless volunteer hours to caring for local habitats, and even setting up neighbourhood watches to combat vandals. This shows a huge opportunity for urban residents to be on the conservation frontline.

Our research focused on 39 species that are restricted to Australian cities and towns today. But that’s not where the opportunity for urban conservation ends.

There are about another 370 threatened species that share their range with urban areas across Australia, as well as countless “common” native species that call cities home. And as cities continue to expand, many other threatened species stand to become urban dwellers. It’s clear that if we only focus conservation efforts in areas far from humans, species like these will be lost forever.The Conversation

Kylie Soanes, Postdoctoral fellow, University of Melbourne and Pia Lentini, Research Fellow, The University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Townsville floods show cities that don’t adapt to risks face disaster


Cecilia Bischeri, Griffith University

A flood-ravaged Townsville has captured public attention, highlighting the vulnerability of many of our cities to flooding. The extraordinary amount of rain is just one aspect of the disaster in Queensland’s third-biggest city. The flooding, increasing urban density, the management of the Ross River Dam, and the difficulties of dealing with byzantine insurance regulations have left the community with many questions about their future.

These questions won’t be resolved until we enhance the resilience of cities and communities against flooding. Adaptation needs to become an integral part of living with the extremes of the Australian environment. I discuss how to design and create resilient urban landscapes later in this article.




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Flood risk and insurance

Another issue that affects many households and businesses is the relationship between insurance claims and 1-in-100-year flood event overlay maps. Projected rises in flood risks under climate change have led to concerns that parts of Townsville and other cities will become “uninsurable” should the costs of cover become prohibitive for property owners.

Council flood data used for urban planning and land-use strategies is also used by insurers to assess the flood risk to individual properties. Insurers then price the risk accordingly.




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However, in extraordinary circumstances, when the flooded land is actually larger than the area marked by the flood overlay map, complications emerge. In fact, that part of the community living outside the map’s boundaries is considered flood-free. Thus, those pockets of the community may have chosen not to have flood insurance and not have emergency plans, which leaves them even worse off after floods. This is happening in Townsville.

Yet this is nothing new. Many people experienced very similar circumstances in 2011. Flood waters covered as much land as Germany and France combined. Several communities were left on their knees.

Notwithstanding the prompt and vast response of the federal government and Queensland’s state authorities, a few years later Townsville is going through something alarmingly similar.

Adaptation to create resilient cities

To find a solution, we need to rethink how to implement the Queensland Emergency Risk Management Framework. That is no easy task. However, it starts with shifting the perspective on what is considered a risk – in this case, a flooding event.

Floods, per se, are not a natural disaster. Floods are part of the natural context of Queensland as can be seen below, for instance, in the Channel Country.

Floods are part of the Australian landscape. Here trees mark the seasonal riverbeds in the Queensland outback between Cloncurry and Mount Isa.
Cecilia Bischeri, Author provided

The concept of adaptation as a built-in requirement of living in this environment then becomes pivotal. In designing and developing future-ready cities, we must aim to build resilient communities.

This is the ambitious project I am working on. It involves different figures and expertise with a shared vision and the support of government administrations that are willing to invest in a future beyond their elected term of office.

Ideas for Gold Coast Resilientscape

I live and work in the City of Gold Coast. Water is a fundamental part of the city’s character and beauty. In addition to the ocean, a complex system of waterways shapes a unique urban environment. However, this also exposes the city to a series of challenges, including flooding.

Last September, an updated flood overlay map was made available to the community. The map takes into account the projections of a 0.8 metre increase in the sea level and 10% increases in storm tide intensity and rainfall intensity.

These factors are reflected in the 1-in-100-year flood overlay. It shows undoubtedly that the boundaries between land and water are changeable.

Building walls between the city and water as the primary flood protection strategy is not a solution. A rigid border can actually intensify the catastrophe. New Orleans and the levee failures during the passage of Hurricane Katrina in 2005 provide a stark illustration of this.

Instead, what would happen and what would our cities look like if we designed green and public infrastructures that embody flooding as part of the natural context of our cities and territory?




Read more:
Design for flooding: how cities can make room for water


The current project, titled RESILIENTSCAPE: A Landscape for Gold Coast Urban Resilience, considers the role of architecture in enhancing the resilience of cities and communities against flooding. The proposal, in a nutshell, explores the possibilities that urban landscape design and implementation provide for resilience.

RESILIENTSCAPE focuses on the Nerang River catchment and the Gold Coast Regional Botanic Gardens, in the suburb of Benowa. The river and gardens were adopted as a case study for a broader strategy that aims to promote architectural solutions for a resilient City of Gold Coast. The project investigates the possibility of using existing green pockets along the Nerang River to store and retain excess water during floods.

Gold Coast Regional Botanic Gardens is one of the green areas along the Nerang River that could be used to store and retain flood water.
Batsv/Wikimedia Commons, CC BY-SA

These green spaces, however, will not just serve as “water tanks”. If mindfully planned, the green spaces can double up as public parks and facilities. This would enrich the community’s social realm and maximise their use and return on investment.

The design of a landscape responsive to flooding can, by improving local urban resilience, dramatically change the impact of these events.

The goal of creating urban areas that are adaptive to an impermanent water landscape is the main driver of the project. New Orleans after Hurricane Katrina and New York after Sandy are investing heavily in this direction and promoting international design competitions and community participation to mould a more resilient future. Queensland, what are we waiting for?




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Floods don’t occur randomly, so why do we still plan as if they do?



This article has been updated to clarify the use of flood data by insurers in assessing risk and the cost of cover.The Conversation

Cecilia Bischeri, Lecturer in Architecture, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How do we save ageing Australians from the heat? Greening our cities is a good start



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A shade tree makes a big difference to the comfort of this couple.
Nancie Lee/Shutterstock

Claudia Baldwin, University of the Sunshine Coast; Jason Byrne, University of Tasmania, and Tony Matthews, Griffith University

Heatwaves have killed more Australians than road accidents, fires, floods and all other natural disasters combined. Although recent research shows extreme cold is a worry in some parts of Australia, our hottest summer on record points to more heat-related deaths to come. The record heatwaves have highlighted the damaging effects of heat stress. Understandably, it’s becoming a major public health challenge.




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The risk of extreme heat events and the adverse impacts on older people has been extensively discussed in research. Remarkably, very little attention has been paid to the role of urban greenery in reducing heat stress for seniors.

Older people are particularly at risk of heat stress. Pre-existing medical conditions and limited mobility increase their vulnerability. Deaths of older people increase during extreme heat events.

The physical features of urban areas shape the capacity of older adults to engage in many activities when it’s hot. These include vegetation volume and coverage, thermal design, and the extent of shading in public areas and walkways. Increasing urban greenery may offer a way to improve older people’s comfort and social experience.




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Building cool cities for a hot future


Ageing adds urgency to greening

It is expected 20% of the global population will be older than 60 by 2050. The figure for Australia is even higher, at 23%. This means that by 2050 around one in four Australians will be more vulnerable to extreme heat.

Older people are more vulnerable to heat stress.
PorporLing/Shutterstock

Climate change may make the problem worse by fuelling even more extreme heat events.

Planning our urban centres to meet the needs of a rapidly ageing population is a matter of urgency. Urban greening to reduce their vulnerability to heat stress should be central to this agenda. It can also improve people’s quality of life, reduce social isolation and loneliness, and ease the burden on health systems.

An important task is matching the design of communities with the needs of an ageing population. Where older adults live and the quality of their local areas strongly influence their lived experiences. Yet recent research found the experiences of seniors were often not accounted for in research on neighbourhood design.




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What about aged care?

People face choices about where they live as they age. The common choices are to “age in place” or to move into aged care.

Ageing in place includes living in one’s own home or co-habiting with relatives or friends. Around 90% of Australian seniors choose this option, with the remainder opting for aged-care facilities.

If one in ten Australian seniors live in aged-care facilities, it is clear these should be designed to minimise heat stress. This isn’t just good for residents; it may also benefit operators by lowering health-care and electricity costs.

While these facilities are purpose-built for older people, many in Australia were built well over a decade ago, when heat stress was not such a large concern. Many more facilities are being built now and will be into the future. Yet it is uncertain whether they are being actively designed to reduce the impacts of heat.




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What has our research found?

We recently conducted a focus group to investigate this issue. Participants were senior managers from four large corporate providers of aged care in Australia. We investigated if and how providers try to minimise heat stress through design. We also sought to understand the rationales used to support these design approaches.

Several participants reported on refurbishments that they expect will have cooling effects. Cited design approaches included green roofs and walls, as well as sensory gardens. Other expected benefits included reducing anxiety and improving the mental health of residents.

The fact that single design interventions could produce multiple benefits improved the potential for corporate buy-in. Participants expected that increasing green space and green cover would give their facilities a competitive advantage by attracting more clients and providing a better working environment for staff.

Participants also reported on challenges of including greening in their projects. For example, the benefits of trees were weighed against concerns about roots disrupting footpaths and becoming trip hazards. Species selection was another concern, with fears that inappropriate plants could die and undermine support for greening programs.

Our research suggests that more can be done to make cities hospitable for older people, especially during extreme heat. Urban greening is a start. Encouraging aged-care providers to adopt green infrastructure will have benefits. But we should also consider reforms to planning systems and urban design to better protect older people who choose to age in place.




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If planners understand it’s cool to green cities, what’s stopping them?


The Conversation


Claudia Baldwin, Associate Professor, Urban Design and Town Planning, Sustainability Research Centre, University of the Sunshine Coast; Jason Byrne, Professor of Human Geography and Planning, University of Tasmania, and Tony Matthews, Senior Lecturer in Urban and Environmental Planning, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Koalas can learn to live the city life if we give them the trees and safe spaces they need


Edward Narayan, Western Sydney University

Australia is one of the world’s most highly urbanised nations – 90% of Australians live in cities and towns, with development concentrated along the coast. This poses a major threat to native wildlife such as the koala, which can easily fall victim to urban development as our cities grow. Huge infrastructure projects are planned for Australian cities in the coming few years.

The need to house more people – the Australian population is projected to increase to as much as 49.2 million by 2066 – is driving ever more urban development, much of it concentrated in our biggest cities on the east coast. This is bad news for the koala population, unless the species’ needs are considered as part of planning approvals and the creation of urban green spaces. The good news is that koalas can learn to live the “green city life” as long as they are provided with enough suitable gum trees in urban green spaces.




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Indeed, our newly published research, which analysed stress levels in wild koalas according to their habitat, reveals that koalas are the most stressed in rural and rural-urban fringe zones. This appears to be due to factors such as large bushfires, heatwave events, dog attacks, vehicle collision and human-led reduction of prime eucalyptus habitats. Koalas living in urban landscapes are less stressed as long as the city includes suitable green habitats.

If there are suitable trees, koalas can learn to live among us – this one is next to a school in South Australia.
Vince Brophy/Shutterstock

In other words, wild animals including the koala can adapt to co-exist with human populations. Their ability to do so depends on us giving them the space, time and freedom to make that adaptation. This means ensuring they can carry out, without undue pressures, the biological and physiological functions on which their survival depends.

Wildlife species that lack access to suitable green habitats in cities are at higher risk of death and local extinction. Having to move between fragmented patches of habitat increases the risks. Land clearing and habitat destruction for infrastructure projects and other urban development are compounding the major threats to koalas, such as being hit by vehicles or attacked by dogs.




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Koalas are feeling the heat, and we need to make some tough choices to save our furry friends


How does human pressure cause stress in wildlife?

Animals cope with stressful situations in their lives through very basic life-history adjustments and ecological mechanisms. These include changes in physiology and behaviour in response to stresses in their environment.

We can help make the environment more suitable for wildlife species by ensuring their basic needs for food, water and shelter are met. If animals are deprived of any of these necessities, they will show signs of stress.

So by subjecting wildlife to extrinsic stressors such as habitat clearance, climate change and pollution we are making it even more difficult for these animals to manage stress in their daily lives.

Basically any unwanted change to an animal’s environment that prevents it from performing its basic life-history functions, such as foraging and social behaviour, will cause stress.

So what can be done?

The koalas are telling us it’s a major problem when urban design is not green enough. Innovative solutions are needed!

Cities can do much more for wildlife conservation. Creating safe green spaces for wildlife is critical. Not just koalas but other wildlife such as birds, small mammals, reptiles and frogs can benefit immensely from urban green spaces.

Even in suburbs with plenty of green space, problems still arise because urban planning typically designs this space around access for human recreation and not for the wildlife that was living there before the housing development moved in.

Urban planning should always incorporate the planning of green spaces that are safe for wildlife. Providing wildlife crossings is part of the solution. Another important element is educational programs to alert drivers to the need to look out for koalas.




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Safe passage: we can help save koalas through urban design


Measures like this can minimise impacts on wildlife that faces the many challenges of adjusting to city life.The Conversation

Edward Narayan, Senior Lecturer in Animal Science, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cities turn to desalination for water security, but at what cost?



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The largest desalination plant in Australia, Victoria’s A$3.5 billion ‘water factory’ can supply nearly a third of Melbourne’s needs.
Nils Versemann/Shutterstock

Ian Wright, Western Sydney University and Jason Reynolds, Western Sydney University

This is the first of two articles looking at the increasing reliance of Australian cities on desalination to supply drinking water, with less emphasis on alternatives such as recycling and demand management. So what is the best way forward to achieve urban water security?


Removing salts and other impurities from water is really difficult. For thousands of years people, including Aristotle, tried to make fresh water from sea water. In the 21st century, advances in desalination technology mean water authorities in Australia and worldwide can supply bountiful fresh water at the flick of a switch.

Achieving water security using desalination is now a priority for the majority of Australia’s capital cities, all but one of which are on the coast. Using the abundance of sea water as a source, this approach seeks to “climate proof” our cities’ water supplies.




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It’s hard to believe now that as recently as 2004 all Australian capital city water authorities relied on surface water storage dams or groundwater for drinking water supplies. Since Perth’s first desalination plant was completed in 2006, Australian capital cities have embraced massive seawater desalination “water factories” as a way to increase water security.

Perth and Adelaide have relied most on desalination to date. Canberra, Hobart and Darwin are the only capitals without desalination.

The drought that changed everything

From the late 1990s to 2009 southeastern Australia suffered through the Millennium Drought. This was a time of widespread water stress. It changed the Australian water industry for ever.

All major water authorities saw their water storages plummet. Melbourne storages fell to as low as 25% in 2009. The Gosford-Wyong water storage, supplying a fast-growing area of more than 300,000 people on the New South Wales Central Coast, dropped to 10% capacity in 2007.

These were familiar issues in locations such as Perth, where the big dry is epic. For more than four decades, the city’s residents have been watching their supply of surface water dwindle. Remarkably, only about 10% of Perth’s water now comes from this source.

Perth’s two desalination plants have a combined output of up to 145 billion litres (gigalitres, GL) a year. That’s nearly half the city’s water needs. Both have remained in operation since they were built.




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Is Perth really running out of water? Well, yes and no


Modern industrial-scale desalination uses reverse osmosis to remove salt and other impurities from sea water. Water is forced under high pressure through a series of membranes through which salt and other impurities cannot pass.

Design, construction and maintenance costs of these industrial plants are high. They also use massive amounts of electricity, which increases greenhouse gas emissions unless renewable energy sources are used.

Another concern is the return of the excess salt to the environment. Australian studies have shown minimal impact.




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Fixing cities’ water crises could send our climate targets down the gurgler


Just as many of the massive new desalination factories were completed, and proudly opened by smiling politicians, it started raining. The desalination plants were switched off as storages filled. However, water consumers still had to pay for the dormant plants to be maintained – hundreds of millions of dollars a year in the case of the Melbourne and Sydney plants.

Bringing plants out of mothballs

Now drought has returned to southeast Australia. Once again, many capital city water storages are in steep decline. So what is the response of water authorities in the desal age? Not surprisingly, more desalination is their answer.

One by one the desalination plants are being switched back on. Sydney has just begun the process of restarting its plant, which was commissioned in 2010. Adelaide has plans to greatly increase the modest output from its plant this year. The Gold Coast plant, which can also supply Brisbane, is operating at a low level in “hot standby” mode.

After a dry winter, Melbourne Water is expected to advise the Victorian government to make the largest orders for desalinated water since its plant, able to produce 150GL a year, was completed in December 2012. Mothballed for more than four years, it supplied its first water to reservoirs in March 2017. The previously forecast need for 100GL in 2019-20 (annual orders are decided in April) is almost one-quarter of Melbourne’s annual demand. Plant capacity is capable of being expanded to 200GL a year.

When bushfires recently threatened Victoria’s largest water storage, the Thomson dam, the government said desalinated water could be used to replace the 150GL a year taken from the dam.

Sydney’s plan for future droughts is to double the output of its desalination plant from 250 million litres (megalitres, ML) a day to 500ML a day. This would take its contribution from 15% to 30% of Sydney’s water demand.

Perth, Adelaide, Melbourne, Brisbane and the Gold Coast already have the capacity to supply larger proportions of their populations with desalinised water as required.

What about inland and regional settlements across Australia? Large-scale desalination plants may not viable for Canberra and other inland centres. These regions would require sufficient groundwater resources and extraction may not be environmentally sound.

How much, then, do we pay for the water we use?

The plants supplying our biggest cities cost billions to construct and maintain, even when they sit idle for years.

The Australian Water Association estimates the cost of supplying desalinated water varies widely, from $1 to $4 per kL.

In fact, water costs in general vary enormously, depending on location and how much is used. The pricing structures are about as complex as mobile phone plans or health insurance policies.

The highest price is in Canberra where residents pay $4.88/kL for each kL they use over 50kL per quarter. The cheapest rate is Hobart’s $1.06/kL.

The issue of water pricing leads on to the question of what happened to the alternative strategies – recycling and demand management – that cities pursued before desalination became the favoured approach? And how do these compare to the expensive, energy-hungry process of desalination? We will consider these questions in our second article.


This article has been updated to clarify the status of advice on Melbourne’s use of desalinated water.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University and Jason Reynolds, Research Lecturer in Geochemistry, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cities can grow without wrecking reefs and oceans. Here’s how



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Cairns has lots of hard grey infrastructure but much less green infrastructure that would reduce the impacts of the city’s growth.
Karine Dupré, Author provided

Silvia Tavares, James Cook University and Karine Dupré, Griffith University

What happens if the water temperature rises by a few degrees?” is the 2018 International Year of the Reef leading question. While the ocean is the focus, urbanisation is the main reason for the rising temperatures and water pollution. Yet it receives little attention in this discussion.

In turn, rising temperatures increase downpours and urban floods, adding to the pressures on urban infrastructure.




Read more:
Design for flooding: how cities can make room for water


Protecting the reef as Cairns grows

Cairns is an expanding Queensland city located between two World Heritage sites – the Great Barrier Reef and the Daintree Rainforest. While important research focuses on these sites themselves, not much is known about how the surrounding urban areas influence these natural environments. Similarly, little is known about how urban planning and design contribute to the health of the inner city and surrounding water bodies, including the ocean.

Cairns is a major Australian tourism destination with a unique coastal setting of rainforest and reef. This attracts growing numbers of visitors. One effect of this success is increased urbanisation to accommodate these tourists.

There are many opportunities to promote sustainable and socially acceptable growth in Cairns. Yet this growth is not without challenges. These include:

  • impacts of climate change, including sea-level rise and ocean warming
  • lack of comprehensive urban infrastructure strategy
  • lack of comprehensive assessment of the benefits of integrated urban design to maximise coastal resilience and the health of streams and oceans.
Rain gardens are common in Singapore.
Roger Soh/Flickr, CC BY-SA

As with most Australian cities, Cairns has an urban layout based on wide streets, mostly with little or no greenery. Rain gardens, for instance, are rare. Bioswales that slow and filter stormwater are present along highways, but seldom within the city.

The arguments for not adding greenery to the urban environment are familiar. These typically relate to costs of implementation and maintenance, but also to the speed with which water is taken out of streets during the tropical rainy season. This is because green stormwater solutions, if not well planned, can slow down the water flow, thus increasing floods.

However, cities can be designed in a way to imitate nature with solutions that are an integral part of the urban system. This can include dedicated areas of larger wetlands and parks, which capture water and filter pollution and undesired nutrients more efficiently, reducing polluted runoff to the reef.




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If planners understand it’s cool to green cities, what’s stopping them?


Integrated urban design

Integrated urban design is an aspect of city planning and design that could be further developed to ensure the whole system works more efficiently. This involves integrating the three elements that make up urban infrastructure:

  1. the green – parks, residential gardens, rain gardens, green roofs and walls, bioswales, etc
  2. the grey – built drains, footpaths, buildings, underground vacuum
    system
    , etc
  3. the blue – streams, stormwater systems, etc.
A rain garden, which absorbs rain and stores water to help control run-off from impervious hard surfaces, in Wellington, New Zealand.
Karine Dupré

Urban infrastructure, therefore, can and should be planned and designed to provide multiple services, including coastal resilience and healthier water streams and oceans. To achieve this, a neighbourhood or city-wide strategy needs to be implemented, instead of intermittent and ad hoc urban design solutions. Importantly, each element should coordinate with the others to avoid overlaps, gaps and pitfalls.

This is what integrated urban design is about. So why don’t we implement it more often?

Challenges and opportunities

Research has shown that planning, designing and creating climate-resilient cities that are energy-optimised, revitalise urban landscapes and restore and support ecosystem services is a major challenge at the planning scale. To generate an urban environment that promotes urban protection and resilience while minimising urbanisation impacts and restoring natural systems, we need to better anticipate the risks and have the means to take actions. In other words, it is a two-way system: well planned and designed green and blue infrastructures not only deliver better urbanised areas but will also protect the ocean from pollution. Additionally, it helps to manage future risks of severe weather.

The uncertainties of green infrastructure capacity and costs of maintenance, combined with inflexible finance schemes, are obstacles to integrated urban solutions. Furthermore, the lack of inter- and transdisciplinary approaches results in disciplinary barriers in research and policymaking to long-term planning of the sort that generates urban green infrastructure and its desired outcomes.

On the bright side, there is also strong evidence to suggest sound policy can help overcome these barriers through technical guides based on scientific research, standards and financial incentives.




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Here’s how green infrastructure can easily be added to the urban planning toolkit


Collaborative partnerships are promising, too. Partnerships between academia and industry tend to be more powerful than streamlined industry project developments.

Finally, and very promisingly, Australia has its own successful green infrastructure examples. Melbourne’s urban forest strategy has been internationally acclaimed. Examples like these provide valuable insights into local green infrastructure governance.

Cairns has stepped up with some stunning blue infrastructure on the Esplanade which raises awareness of both locals and visitors about the protection of our oceans.

This is only the start. Together academics, local authorities, industry stakeholders and communities can lead the way to resilient cities and healthier oceans.

Cairns Esplanade Lagoon helps raise awareness of the need to protect the ocean as the city grows.
Karine Dupré, Author provided



Read more:
How green is our infrastructure? Helping cities assess its value for long-term liveability


The Conversation


Silvia Tavares, Lecturer in Urban Design, James Cook University and Karine Dupré, Associate Professor in Architecture, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.