The ingredients making up the new concept “sustainable urban water” are simple: rainwater, drinking water, waste water and recreational water.
COWI is working together with the Danish Hydraulic Institute and consultancy ALECTIA Aqua to develop the idea that sustainable water solutions should be integrated into new cities and neighbourhoods.
Senior Project Manager Jes Clauson-Kass, a water expert, explains that the motivation for the concept is that pressure on the world’s water resources can only be mitigated if sustainable water and sewage networks are installed in cities.
“Our basic premise is that all water begins as rainwater,” Clauson-Kaas says. “It then runs off into streams, lakes or underground aquifers. A sustainable use of rainwater will involve using precipitation locally, which reduces the cost of treatment and transport, as well as helping to prevent drought and flooding.”
Urban seals
He points out that newly constructed cities act as a seal on the surface of the earth by preventing water from being absorbed by the ground.
“Instead, water runs off to the sea. A more sustainable approach will ensure a constant supply of groundwater by storing rainwater in decentralised ponds, small lakes or underground tanks that will slowly release the water into the soil.”
Seeking: test city
The big challenge right now for the team working on the sustainable urban water project is finding a city they can use as a proving ground for their ideas.
Currently, they rely on computer models that can calculate how existing water resources and rainwater runoff from specific areas interact. The models can simulate the conditions of an empty field or a new city housing 500,000 people all putting pressure on water supplies.
“Just like computer game developers need people to test their games,” Clauson-Kass says, “we need to find a city that we can use to test our ideas so we can continue to put our ideas into practice and move on to new stages of development.”
Markets rising in the east
The group is keeping an especially close watch on China, which they say has major problems with its water supplies.
“Especially northern China,” Clauson-Kaas says. “Within the past couple of years, 40 new cities have been built, and many of those cities would benefit from our concept.”
The Gulf region, which has also seen cities sprouting up and water supplies dwindling, is another area the group is watching.
Should a pilot city be found and the concept fully developed, Clauson-Kaas predicts that the three partners could become world leaders when it comes to establishing sustainable urban water and sewage systems.
By Kathrine Schmeichel, kats@cowi.com
Published: 04.08.2010
