A new approach to urban planning that can save water
Scientists are developing strategies to help cities around the world find sustainable water systems.
Imagine for a moment a raindrop falling high above a modern-day city. After it reaches a roof, a street or the top of a car, it's quickly whisked away toward a gutter or drain, picking up pollutants and sediments along the way. There it collects into larger torrents, all the while moving faster and further from its point of impact. Eventually, that single drop and nearly all of the precipitation that falls is removed far outside the urban environment; bringing with it elevated levels of chemicals, trash and other harmful pollutants.
With growing populations, expanding development, and increasing water scarcity, handling stormwater with such a linear approach is no longer an option for many parched cities. From Los Angeles to Melbourne to Tel Aviv, urban centers around the globe are rethinking their relationship with water and how best to create a secure, safe and sustainable supply moving forward.
The philosophy, known as "water-sensitive urban design," examines the water cycle at all levels; from rainwater to drinkable water, wastewater and groundwater. It then determines the best way to use all of these streams as a resource for recreation, landscape renewal, and general use.
It's not necessarily a new practice. Officials in drought-stricken Australia have been pursuing efficiency in water design for quite some time, but with a changing global climate and increasing demand for resources, water sensitivity is now clearly on the minds of all urban planners.
In an effort to help assist cities worldwide, scientists from universities in Israel and Australia have started working together on a project that addresses water management in an urban environment. Areas of research include the addition of surfaces that allow water to reach the ground below, green roofs to reduce heating and cooling costs, urban gardens to improve biodiversity and specialized filters to harvest and reuse storm water. They are also analyzing pollution in rainwater to understand how best to treat it before reclamation. The scientists hail from three Israeli universities – Ben-Gurion University, the Israel Institute of Technology and Hebrew University – and Monash University in Australia.
By establishing water as part of a city's design, flow will no longer be directed away, but within. Rainwater will be collected, wastewater will be treated and reused, and integrated lakes, ponds, and gardens will enhance both aesthetics and filter out unwanted pollutants.
Tracy Quinn, a water policy analyst for the National Resources Defense Council in California, said that collaborative studies like this one can go a long way to helping cities faced with drought take meaningful steps to better secure water supplies from above.
"One of the most incredible things about stormwater is that we have taken one of our largest resources – rain – and designed cities to take that resource away as soon as possible,” she said. "We put in storm sewers to get it to the nearest river or ocean, and we’ve transformed our greatest resource into our greatest source of pollution."
The researchers plan on putting some of their ideas into practice later this fall, focusing on four cities in Israel with a need for greater water management. Once the study is complete, the findings will be shared with other global cities in the hope of helping spread water sensitive design around the world.
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