Synergy between measures aimed at improving water management in urban areas and measures meant to improve the green urban environment can produce interesting benefits (ecosystem services), such as:
– Storage of water during peak flows
– Retention of water for covering seasonal shortages
– Green space, for recreation and urban landscaping
– Water for vegetation during dry periods; reduced need for irrigation
– Stimulation of natural purification processes, producing cleaner water
– Public health, as conditions for survival of pathogens and vectors are unfavourable;
– Shading
– Evaporative cooling during hot days
– Solar (thermal) energy collector
– Attractive biotopes for a wide variety of species
– Production of biofuels
– Production of crops e.g in urban agriculture/horticulture and urban forestry
– Job creation
– Value creation due to improved urban landscape, flood protection and water quality; property values close accessible urban green and surface water increases
Examples of effective blue-green solutions are:
– Vegetated filter swales (wadi’s)
– Grassed filter verges
– Puri-drains
– Biofilters
– Bio-activated canals
– Artificial wetland
– Greened septic tanks
– Rain gardens
– Activated green roofs and facades
– Green stormwater harvesting facilities
– Street greening for cooling and water retention
– Uchimizu; wetting pavement for lowering ambient temperature
Some of these solutions are already applied by frontrunners, in particular in the USA and Australia. Most of these technologies can however be improved further to improve their performance and to create extra benefits. An illustration of some small scale examples of blue-green solutions as implemented in Portland (USA). Photo’s by Tom Liptan.
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Blue-green solution at parking lots to avoid stormwater problems: from design into practice |
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Blue-green solutions in working: urban green constructed such that it has the capacity to buffer storm water |
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Testing of blue-green solutions in practice:
Additional green elements at street level may reduce run-off peaks in sewer systems. |
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Education for citizens on the use and benefits of blue-green solutions |
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Implementation of blue-green solutions in residential areas (left), designed such that its added value is clear to the general public (right). |
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Demonstration sites (left) on the functioning of green roofs increases the support and thereby the application of these blue-green solutions (right).
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