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Case Studies from Around the
WorldTanuja Ariyananda
LRWHF
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Star City
Location: Seoul, Korea
Extend: Built on a 6.25 hectaresite, originally owned by
Konkuk University 4 apartment towers with 1,310
apartments, completed in 2007
Municipality refused on theground that it will increase
storm water flow: Overall, theprecipitation has increased, withmore rainfall in summer and lessin spring.
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Design 3% subsidy to build 40
apartments to be built where the plans already
allowed for three undergroundstory's for car parking. A fourth
sub-surface storys would nowbe added to accommodaterainwater in two meter deeptanks
Each block has a plan areaof1500m2
Rainwater from all four roofs ispiped to the RWH basementunder the 35 storeysblockwhere there are 3 separatestorage tanks each of1000m3capacity.
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Multi Purpose Rainwater Management
Floodontrol
WaterSaving Emergency
1000 M3 1000 M3 1000 M3
For Others !!! For Myself !!! For All of us !!!
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Operation
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Benefits Monthly monitoring programme shows that some 40,000m3 of rainwater has beenharvested and beneficially used over the 12 month period. Estimated about 67% of the rainfall on the site With average consumption from the public supply amounting to 250 litres/head/day
in Seoul, it is no surprise to learn that Star City residents welcome the reduced waterrate resulting from the harvesting scheme.
Reduction in flood risk in a floodprone area.
Considering the average cost of Supplying one cubic meter of tap water in Korea is about seven U.S. dollars, the
saving is significant to the city, while the residents will save about US$ 80,000 peryear in reduced payment for water.
The construction cost for the rainwater harvest system was approximately US$450,000
Energy saving Energy required to treat and deliver a cubic metre of tap water is 1.8244kWh Treatment of grey water (treated on site) 1.1177kWh per cubic metre Rainwater needing no transport or treatment, can be delivered for a mere 0.0012kWh, the
pumping energy needed to raise the water from storage.
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Capture The Rain
the skyscraper features an innovativeroof and external shell, which consistsof a system of gutters to harvestrainwater to meet the daily needs of itsinhabitants.
The designers estimate that theaverage daily consumption of waterper person is about 150 liters, out ofwhich 85 liters may be replaced byrainwater
A network of gutters on the externalsurface of the building is designed to
capture rainfall flowing down thebuilding. While most of the harvestedwater is supplied to the apartments,surplus water is stored in a reservoirunder the building.
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Rain House