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Urban water design: strategies for future cities

20 Feb 2012 (Last Updated February 20th, 2012 18:30)

Sustainably integrating water into modern cities will be one of the biggest challenges faced by future urban planners. Elisabeth Fischer explores interdisciplinary water-sensitive urban design strategies that will help secure city life for future generations.

With the population forecast to reach nine billion within the next 30 years and cities expected to grow to substantially bigger sizes, urban water design will be one of the biggest issues to be solved in the years ahead.

In order to secure urban life for future generations, urban water management and drainage needs to combine functionality with the designed environment of a city. For the first time, city planners and designers play a crucial role in providing water for a city – pursuing a truly interdisciplinary strategy to secure urban life for future generations.

"Water will be our greatest challenge in the future and the place to meet this challenge has to be the urban context," claimed AECOM sustainability director Celeste Morgan talking at a New London Architect (NLA) breakfast talk on water and urban drainage in November 2011.

"It’s really the nexus where all of our problems with water come together as that’s where we’ve got the greatest water demand from an intense population."

Water-sensitive urban design

"Increasing numbers of flood and drainage problems called for a system to harmonise the urban environment and urban water cycle."

Celeste Morgan believes the biggest problem today is the fact that water management in cities is still too much of an engineering field and usually happens without involving city planners, designers and architects. "People that help to create our cities should be getting involved in water management, helping to create better options," she said.

In Australia, where most big cities are located on the south-eastern coastline, a new concept of water management was introduced by city councils over the last two decades.

The increasing number of floods and drainage problems called for a water management system that strived to harmonise the urban-built environment and the urban water cycle, combining the functionality of water management with principles of urban design: water-sensitive urban design (WSUD).

Building on governmental foundational research conducted in the 1990s, all Australian states released water guidelines, which then resulted in the signing of the National Water Initiative (NWI) June 2004. This scheme provides a comprehensive national strategy to improve water management – with WSUD being one of its key pillars.

WSUD can widely be defined as the integration of urban planning and development with the management, protection and conservation of the water cycle as a whole.

According to Melbourne Water, its key principles include the protection of natural systems and water quality, the integration of stormwater treatment into the landscape, reduction of run-offs and peak flows and lowering the cost of urban drainage developments.

But the most important aspect is that water management now has to be planned in one single forum that integrates designers, architects, planners, landscape architects, developers, water engineers, ecologists and sustainable builders.

Urban water design in the US and Europe

What has been the norm in Australia is still fairly new in wide parts of the US and Europe. Some cities have sporadically started to implement measures surrounding WSUD.

"Water will be our greatest challenge in the future and the place to meet this challenge has to be the urban context.

In the US, for instance the city of Portland in Oregon introduced a set of different sustainable stormwater management programmes in 2008 that counteract combined sewer system overflows while enhancing greenery in the city.

Celeste Morgan believes Portland has done it right, integrating all aspects from design to engineering and architectural landscaping into WSUD. "We have to stop thinking about buildings plot by plot," she said. "Just like in Portland, we have to start thinking of a city as a whole, getting an interaction between landscape and water."

In Europe, Germany has become a forerunner, with medium and small scale projects being realised throughout its cities. In Stuttgart for example, urban planners STEG Stadtentwicklung implemented, in cooperation with water engineers, landscape architects and other architects, a project in the district of Hohlgrabenäcker that saves costs for stormwater management through the application of green roofs and cisterns – all for a fragment of the costs the city would have paid to enlarge its existing sewer system.

One widely appraised small-scale project is the one at Potsdamer Platz in Germany’s capital Berlin. Designed by Atelier Dreiseitl, it was awarded with the DGNB Certificate of the German Sustainable Building Council for sustainable city quarters. The waterscape project combines rainwater harvesting with a recreational cityscape, forming a natural habitat.

About 50% of the rainwater is used for irrigation, the pools and the canals in the area, while the rest goes into the buildings to flush lavatories and supply fire extinguishing systems.

Five giant underground cisterns can house excess water in case of extremely heavy rain. From there, the water is fed into the system of canals and biotopes – without wasting a single drop.

London: water strategies for the future

"The next big thing in urban water design will be the total water-cycle city, creating multifunctional architectural solutions."

Europe’s sore spot is to be found further west, in the UK, as Celeste Morgan explained: "The relationship between London and its water sources is quite troubled and abusive. The Fleet River has completely disappeared as we’ve paved over the top of it. We’ve created pollution and stormwater run-off problems and that’s why we have problems with flooding."

She added: "As a nation I think we’re quite scared of change and risk so even though all these things seem nice to have, are we really making the move toward a more sustainable water future?"

According to Greater London Authority (GLA) strategy manager for climate change adaption and water Alex Nickson, this will change soon with the new water strategy ‘Securing London’s Water Future’, introduced by Mayor Boris Johnson in October 2011.

"Key challenges for London are first of all balancing supply and demand. We have to recognise that we’re taking more water out of the environment than we have available today," explained Nickson at the NLA breakfast.

"We’re causing physical damage to our environment as our population changes, as our climate changes and as we become probably more forced by legislation and framework directives that we cannot keep taking more water out."

"We need to look at how we actually start to retrofit our homes and businesses. We want to move towards greater water efficiency and carbon efficiency and that’s why we have to tackle the existing building stock," he continued. Here again, the teamwork between planners, engineers and architects will be the best key to success.

The future: total water-cycle cities

According to Celeste Morgan, the next big thing in urban water design will be the total water-cycle city, creating multifunctional architectural solutions.

This concept will look upon various transformed forms of water within the water cycle as a resource and match each end use with water quality that is fit for purpose, rather than using drinking quality for water for all uses.

A framework for a total water cycle management (TWCM) to 2030 has recently been introduced in Sydney, integrating the three key elements of the urban water cycle: stormwater, wastewater and potable water.

Even though it’s still a vision, Morgan believes this should be the result in every city, with water management design elements dominating modern cityscapes. "It should be about places, it should be about a city that looks great and really embraces water," she said.

"Water is not seen as a danger, it’s not seen as a problem but it’s really seen as a solution of how a city should be."