1. “ VARSHA JAL SANCHAYAN “
RAINWATER HARVESTING
BY:
PRIYA PANDEY
III YEAR
E.C.E

2. WHY TO HARVEST RAIN ???
o In areas where there is inadequate groundwater supply
or surface resources are either lacking or
insufficient, rainwater harvesting offers an ideal
solution.
o Helps in utilizing the primary source of water and
prevent the runoff from going into sewer or storm
drains, thereby reducing the load on treatment plants.
o Reduces urban flooding.
o Recharging water into the aquifers help in improving the
quality of existing groundwater through dilution.

3. Only 2.5 per cent of all
the world’s water is
fresh, i.e., fit for human
consumption, agriculture
and industry.

4. In troubled waters Bleak future

5. March 20, 2002: There are more " To Let" Boards visible in the
New Washermanpet
area of Chennai than any other part of the city. Some families
have vacated their houses.
Others are just waiting for their children to complete their final
exams before they can leave. The reason? Erratic water supply.
April 4, 2002: 150 residents of Savarkundla town in
Amreli, Gujarat, took out a fanas
(lantern) procession to protest against the lack of water. Others
climbed on to terraces, and rang bells (to awaken the
administration).
April23, 2002: In Kurnool town of Andhra Pradesh, protesters
chased and drove away tankers from the municipal corporation
premises.
May 1, 2002: An acute scarcity of drinking water continues at
villages Balaha Khurd and Nangalia in Nurnaul, Haryana.
Women are commonly seen roaming around with pitchers on
their head, looking for water.
May 13, 2002: When Rajibai of Jaora, a small town in Madhya
Pradesh, went to collect water from a tap, she and her two sons
were brutally beaten up by other residents. This led to a riot that
left four people injured.

6. WHAT IS THE SOLUTION ???

7.  RAIN, OF COURSE :
The source of all water is rain.
 SUPPY COMES FROM THE SKY :
In order to meet demand, then, what we
actually need to do is harvest the rain.
 HARVESTING WATER MEANS HARVESTING
THE RAIN :
We get about 100 hours of rain in a year.

8. THE HIDDEN LINK
Region Annual Rain yield Human Land Surface Number of
people whose
level of potential populatio availabilit quality for water needs
rainfall from one n density y for water can be met at
100 litres per
hectare of water collection person per day
land harvestin efficienc from one
hectare of land
g
Rural - 100 mm 1 million low high - 27
arid litres
Rural - 2000 mm 20 million high low - 553
humid litres
Urban - - Very high Very low More rooftops
and built-up
surfaces
available with
high runoff

9. A survey
conducted by
CSE of several
drought-struck
villages found that
TRADITIONAL those which had
undertaken
rainwater
harvesting and/or
watershed
development in
earlier years had
no drinking water
problem
CONTEMPORY whatsoever and
even had some
water to irrigate
their crops.

10. This is practiced on a
large scale in cities like
Chennai, Bangalore and
Delhi where rainwater
harvesting is a part of the
state policy.
Elsewhere, countries like
Germany, Japan, United
States, and Singapore
are also adopting
rainwater harvesting.

11. HARVESTING SYSTEM

12. HARVESTING SYSTEM

13. FROM WHERE TO HARVEST RAIN ???
 Rooftops
 Paved and unpaved areas
 Water bodies
 Storm water drains

14. WHETHER TO STORE WATER OR TO
RECHARGE IT
 Delhi, Rajasthan and  In places where the
Gujarat where the total groundwater is saline
annual rainfall occurs or not of potable
during 3 or 4 standards, the
months, are examples alternate system could
of places where be that of storing
groundwater recharge rainwater.
is usually practiced.

16. Rainfall :
i. Quantity
ii. Pattern
Type of catchments Coefficients
Roof Catchments
- Tiles 0.8- 0.9
- Corrugated metal sheets 0.7- 0.9
 Catchment area Ground surface coverings
- Concrete
characteristics : - Brick pavement
0.6- 0.8
0.5- 0.6
Runoff depends Untreated ground catchments
- Soil on slopes less than 10 per
upon the area and cent
0.0 - 0.3
0.2 - 0.5
type of the catchment - Rocky natural catchments
over which it falls as Untreated ground catchments
well as surface - Soil on slopes less than 10 per 1.0 - 0.3
cent 0.2 - 0.5
features - Rocky natural catchments

17. WAY AHEAD
WHAT NATIONS CAN CHOOSE

18. The Real Green Revolution is about achieving local food security. Which
villager wants to depend on Kansas, or Punjab for that matter, for his or her
grain?
A local food security approach attempts to help farmers to produce enough for
themselves, even if they cannot generate a huge marketable surplus. This
means ensuring good agriculture in all types of villages and farms.
 This is the kind of food security every farmer yearns for.
 Large-scale irrigation systems make sense only from the perspective of National Food
Security (so-called).

20. Improve the
productivity of rainfed
land, following a
method of Expand land area
supplemental under major irrigation
irrigation via water schemes
harvesting
CHOICES TO MAKE