As time passed people started to
take everything for granted. Fuel, animals, trees everything! But as each day
goes by slowly everything is exhausted by our unending demands. One
of such thing is water that we can't live without. And since we are the ones
who are exhausting it, its our duty to make sure that we do something to
solve this problem.
One most effecting and kinda easy
solution is rainwater harvesting. It might be a little costly to make but its
an investment that's really profitable and
also environment friendly.
What is rainwater harvesting?
Well, rainwater harvesting is the accumulating
and storing of rainwater for reuse before it reaches the aquifer.
It has been used to provide drinking water, water for livestock,
water for irrigation, as well as other typical uses. Rainwater collected
from the roofs of houses and local institutions can make an important
contribution to the availability of drinking water. It can supplement the
subsoil water level and increase urban greenery. Water collected from the
ground, sometimes from areas that are especially prepared for this purpose, is
called Stormwater harvesting. In some cases, rainwater
may be the only available, or economical, water source. Rainwater harvesting
systems can be simple to construct from inexpensive local materials, and are
potentially successful in most habitable locations. Roof rainwater may not be
potable and may require treatment before consumption. As rainwater rushes from
your roof it may carry pollutants, such as mercury from coal burning buildings,
or bird faeces. Although some rooftop materials may produce rainwater that
would be harmful to human health as drinking water, it can be useful in
flushing toilets, washing clothes, watering the garden, and washing cars; these
uses alone halve the amount of water used by a typical home. Household rainfall
catchment systems are appropriate in areas with an average rainfall greater
than 200 mm (7.9 in) per year, and no other accessible water sources
(Skinner and Cotton, 1992). Overflow from rainwater harvesting tank systems can
be used to refill aquifers in a process called groundwater recharge; though this is a
related process, it must not be confused with rainwater harvesting.
There
are several types of systems to harvest rainwater, ranging from very simple
home systems to complex industrial systems. The rate at which water can be
collected from either system is dependent on the plan area of the system, its
efficiency, and the intensity of rainfall (i.e., annual precipitation (mm per
annum) x square meter of catchment area = litres per annum yield) ... a 200
square meter roof catchment catching 1,000mm PA yields 200 kLPA.
Storage tanks should
be covered to prevent mosquito breeding and to reduce evaporation losses,
contamination and algal growth.
Rainwater harvesting has been used since biblical times. It was done in ancient Palestine, Greece and Rome. Around 3rd Century BC., farming communities in Baluchistan and Kutch used it for irrigation. In Ancient Tamil Nadu, India, Rainwater harvesting were done by Chola kings. Rainwater from Brihadeeswarar Temple was collected in Sivaganga tank. In the Indus Valley Civilization, Elephanta Caves and Kanheri Caves in Mumbai rainwater harvesting alone has been used to supply in their water requirements.
