2. W HAT IS WATER HARVESTING ?
It is the method by which rain
water is collected for later use .
3. U SES OF RAIN WATER HARVESTING
Its used to maintain the underground water table.It is
also called ground water recharge(In the picture)
Since rain water is stored for later use , it can be used
at times of drought.
It reduces soil erosion as the running water is stored
(to a certain extent).
4. T ECHNIQUES OF RAIN WATER
HARVESTING
The most basic type of rain water harvesting is the
method by which the water sliding down the roof
tops is collected by a gutter which goes down the
pipes to be stored . Sometimes the water is let into
the soil to maintain the water table. In US the rooftop
rain water is collected in a sump.
A subsurface dyke is built in an aquifer to obstruct the
natural flow of groundwater, thereby raising the
groundwater level and increasing the amount of
water stored in the aquifer.
5. In largely level terrain , the water harvesting
structures are mainly crescent shaped earthen
embankments or low straight concrete-and-rubble
“check dams” built across seasonally flooded gullies .
Monsoon rains fill ponds behind the structure .
6. WATER HARVESTING IN DIFFERENT
PARTS OF THE WORLD
In China and Brazil rooftop rain water harvesting is practiced for
providing drinking water , water for irrigation , for livestock and
to maintain the water table.
In Bermuda and US all new buildings includes water harvesting
sufficient for the residents.
In UK rain water (water butts) tanks are used for rain water
harvesting
In Australia rainwater harvesting is typically used to supplement
the reticulated mains supply. In south east
Queensland, households that harvested rainwater doubled each
year from 2005 to 2008, reaching 40% penetration at that time
(White, 2009 (PhD)).
7. In Senegal and Guinea-Bissau, the houses of people are
frequently equipped with homebrew rainwater harvesters
made from local, organic materials.
In the Irrawaddy Delta of Myanmar, the groundwater is
saline and communities rely on mud-lined rainwater ponds
to meet their drinking water needs throughout the dry
season. Some of these ponds are centuries old and are
treated with great reverence and respect.
In India :
(i) Khandins and Nadis in Rajastan
(ii)Bandhara and Tals in Maharashtra
(iii)Bhundin in MadhyaPradesh and UttarPradesh
8. (iv) Ahars and Pynes in Bihar
(v) Eris (tanks) in Tamil Nadu
(vi) Surangams in Kerala
(vii)Khattas in Karnataka
