Ironically, water use
in developed countries often is highest in the places where
rain falls the least. Rainwater harvesting is one easy and low
tech solution in reducing domestic water use.
How to utilize rain water
The easiest rainwater source is that which falls in our
gardens. Proper placement of plants, trees, and water
collection areas can turn the site into a water efficient
capture system. Shape the surface of the soil to slowly
runoff, raise paths and terraces and sink all planting areas
to collect the water. Choose plants, preferably native, that
absorb and hold water in their root systems, or pass it down
to the water table. This way, rainwater doesn’t run off into
the streets, where it would end up sewer systems or directly
into a local waterway.
Store the rain in cisterns and barrels
An obvious source of rainwater collection is the roof. Even in
areas with minimal rainfall there is a huge potential for
harvesting water. For example, a roof of a 100 m2 can collect
around 1000 litres per 10 mm of rain.
Rain barrels are an easy way to harvest rainwater, especially
in urban areas; they are low cost, and can be installed to
work with existing gutters and pipes. There is a wide range of
choices for storage tanks. They can be made from wood, metal,
plastic, ferrocement or
fibreglass, ranging in size from small
to large.
Indoor use
All around the world
it’s becoming more common for people to use rainwater indoors
for non-potable uses. These systems can reduce or eliminate
the use of municipal or well water. Most household rainwater
systems use a pump and pressure tank to pressurize water. Many
countries however do not yet have codes covering indoor
rainwater use, and people seeking permits may be required to
filter and disinfect the water, increasing system cost and
complexity. However, research
has shown that rainwater harvested using a well designed
system and protect the water from direct light is safe to use
for laundry, bathing or flushing the toilet. Filtering only a
small amount of water with passive filters such as a ceramic
filter or with slow sand filters for drinking lead to a great
reduction in system cost and offers an affordable solution for
clean water.
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