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What is Rain Water Harvesting? |
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Rain water harvesting (RWH) is
catching rain water when it falls and storing to
use during the non rainy season. Harvested rain
water can be utilized for several purposes including
drinking, washing, gardening, flushing etc. This
is practised throughout the world and it is
increasing in demand. In Sri Lanka, we have been
practising it throughout the history by
collecting water in Wewa or tanks. However
concept of rain water harvesting in houses and
offices etc. is relatively new to us and
according to statistics available,
more than 21,000 rain water
harvesting systems are in operation throughout
the country, mostly in rural areas. |
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RWH in Rural Areas |
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Specially in areas
which are vulnerable to periodic droughts, RWH
is a viable option for the basic water needs. |
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This water can be used for
domestic use including drinking, cooking,
washing and also for the needs of agriculture.
Closed tanks made of brick or cement which
collect water from the roof top are used to
harvest water for domestic use. Open tanks or
wells can be used to collect the surface runoff
water which can be used for agriculture and also
for ground water recharging. |
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Above
ground Tank to collect the roof top |
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A tank
collecting the surface runoff
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RWH in URBAN Areas |
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RWH in Urban areas is
increasingly becoming popular with appropriate
technology. According to studies about 60
percent of rainwater of urban areas flow in to
sea and RWH can make use of this wasted water
and also to certify the use of purified pipe
borne water for appropriate usages. Tanks can be
used to collect water for general use and wells
and pit holes (surface runoff tanks) can be used
to recharge the ground water. Ponds are used in
large facilities such as factories and office
complexes
for collection of rain water. |
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The water collected in tanks
and ponds
can
be used for toilet flushing, washing, cleaning,
laundry, and gardening. However,
rainwater collected in urban areas
is not recommended for drinking and cooking due
to the high level of air pollution, animal
droppings and dust in urban areas. |
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Plastic barrels used to collect rain
water |
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Barrels used to collect rain water |
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