rain water harvesting, water conservation, shortage of water, reasons, solution for water shortage, roof catchment, gutters, down pipes, first flush pipe, filter unit, storage tank,

1. RAIN WATER
HARVESTING
MADE BY: KIRTI GARG
(HEAD GIRL)

2. Reasons of Shortage of
Water
• Population increase
• Industrialization
• Urbanization
(a) Increase in per capita utilization
(b) Less peculation area
• In places where rain fed/ irrigation based crops
are cultivated through ground water
• Decrease in surface area of Lakes, talab, tanks
etc.
1

3. Reasons of Shortage
of Water
• Deforestation
(i) Less precipitation
(ii) Absence of Barriers
(a) Rain drops checked by leaves of tree
(b) Water slowly descends through twigs & trunk
© Humus – acts as reservoir
(d) Tiny creatures – helps percolation
2
31 hectare of forest-6-7 Lac ton of water
(after filtering) top layer can hold 1.2 Lac tons of water

4. What is the
solution ?
• Rain water is the ultimate source
of fresh water
• Potential of rain to meet water
demand is tremendous
• Rain water harvesting helps to
overcome water scarcity
• To conserve ground water the
aquifers must be recharged with
rain water
3

5. Why Rain water
be harvested
• To conserve & augment
the storage of ground
water
• To reduce water table
depletion
• To improve the quality of
ground water
• To arrest sea water
intrusion in coastal areas
• To avoid flood & water
stagnation in urban areas
4

6. What is rain water harvesting ?
• It is the activity of direct collection of rain water
• Rain water can be stored for direct use or can be
recharged into the ground water aquifer
5

7. The roof
catchment are
selectively cleaner
when compared
to the ground
level catchment
• Losses from roof catchment are
minimum
• Built & Maintained by local communities
• No Chemical contamination & only
required filtration
• Available at door step with least cost
16

8. The typical roof top
rain water harvesting
system comprises
•Roof catchment
•Gutters
•first flushing pipe
•Filter Unit
•Storage Tank
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9. Roof catchment
The roof of the house is
used as the catchment
for collecting rain water.
The style construction
and material of the roof
effect its suitability as a
catchment, Roofs made
of corrugated iron
sheet , asbestos sheet,
Tiles or Concrete can be
utilized for harvesting
the rain water
18

10. 19
Gutters
Gutters are channels
fixed to the edges of
roof all around to
collect & transport the
rainwater from the
roof. Gutters can be
made in semi-circular
and rectangular shape
with cement pipe,
plain galvanized iron
sheet, PVC pipes,
bamboos etc. Use of
locally available
material reduce the
overall cost of the
system.

11. Down
Pipe
It is the pipe which carries
the rainwater from the
gutters to the filter &
storage tank. Down pipe is
joined with the gutters at
one end & the other end is
connected to the filter unit
of the storage tank. PVC or
GI pipe of 50mm to 75mm
(2 to”) are commonly used
for down pipe. Bamboo
can be also used wherever
available and possible
20

12. First Flush Pipe
Debris, dust & dirt collect on the roof during non rainy
periods when the first rain arrive. A first flush system
arrangement is made to avoid the entering unwanted
material into the Filter media & storage tank. This is a
simple manually operated arrangement or semi-
automatic system with a valve below the ‘T’ junction
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13. Filter Unit
The filter unit is a container or chamber filled with filter
media such as coarse sand, charcoal, coconut fiber,
pebbles & gravels to remove the debris & dirt from water
that enters the tank. The filter unit is placed over the
storage tank or separately. It may be of Ferro cement
filter unit, Aluminum, Cement rings or Plastic bucket etc.
22

14. Storage Tank
It is used to store the water that is collected from the roof
through filter. For small scale water storage, plastic
buckets, jerry cans, clay or cement jars, ceramic jars,
drums may be used. For larger quantities of water, the
system will require a bigger tank constructed with Ferro
cement or cement rings or plain cement concrete or
reinforced cement concrete or brick or stone etc. The
storage tank is provided with a cover on the top to avoid
the contamination of water from external sources. The
storage tank is provided with pipe fixtures at appropriate
places to draw the water to clean the tank & to dispose of
extra water. A provision for keeping the vessel to collect
the water is to be made.
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15. Size of Storage Tank
• Based on
• No. of person in the House hold
• Per capita water requirement
• No. of days for which water is required
Example
Drinking water requirement for a household with 5 family
members, period 8 months & 6 lpcd
= 5x 180x 6 = 7200 Liters

16. Water available from Roof
Annual rainfall (in mm) x roof area (in sq. m) x co-efficient of run off for
roof
co-efficient of run off
GI sheet 0.9
Asbestos 0.8
Tiled 0.75
Plaster on bricks/ Concrete 0.7
Water available from roof top 800mmx 20 sq.m=12800 Liters per annum

17. Water available from
Roof
Size of Tank =1.2 m dia 1.8 m height
No. of Tanks 4
Volume of Tanks 3.14x1.2x1.2x1.5/4
2.03 cum
2000 liters
Volume of of 4 tanks =
4x2000
8000 Liters
(this can be designed as per requirement)
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18. Cost of Material for
Tank
• 1. Cement 8 bags*Rs. 140.00 1120.00
• 2. Grit .25 Cum 200.00
• 3. Sand .4 Cum 100.00
• 4. Perforated Cement rings 5 No. 1000.00
• 5. P/fabricated Cement rings 4 No. 400.00
• 6. PVC pipe 63mm dia.*10M 200.00
• 7. P/fabricated Asbestos 10mm dia.*10mm 250.00
8. Mason/ Labor charges. 1000.00
9. Transportation 130.00
Total =4400.00
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19. Cost of Material for Filtration
Tank
• 1. P/fabricated cement rings 5*rings 200.00
• 2. Cement 2 bags 280.00
• 3. Sand 2 bags 50.00
• 4. Grit 4 bags 50.00
• 5. Charcoal 20 Kg* 160.00
• 6. Sand for Plastering 4 bags 100.00
• 7. Mason/ Labor 500.00
• 8. White washing 40.00
• 9. Transportation 50.00
Total =1430.00
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20. Total Cost of construction Rs.
4400.00+ Rs. 1430.00= Rs. 5830.00
The cost of mainenance-
1.White washing 100.00
2.Water testing 200.00
for (2 times a year) 300.00
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21. Flooded with Fluoride-G/ water is not
potable
Fluoride is an acute toxin with a rating slightly higher
then lead. It is infect, one of the most bone-seeking
elements known to human beings & groundwater in
India shows the presence of unhealthy quantities of
fluoride. A worrying scenario: daily ingestion of 2
milligram (mg) of fluoride could result in creeping
Skeletal fluorosis after 40 years. Excess fluoride
causes several diseases like Osteoporosis, Arthritis,
Brittle bones, Cancer, Infertility in women, Brain
damage, Alzheimer’s disease & Thyroid disorders
30

22. Flooded with Fluoride-G/ water is not
potable
The very nature of fluoride increases this danger
manifold. Almost half of each day’s fluoride intake is
retained & is absorbed by the bones & teeth. It was
Gerald Cox, of the Mellon Institute in the US, who first
found in 1938 that while 1mg/ liter of fluorine in
water prevents dental caries over 1.5mg/l causes
mottled teeth. The bureau of Indian Standards (BIS)
standard for fluoride content is 1-1.5mg/l. It is
believed that levels above or below this could cause
de4ntal decay. Ironically, there is an increased
incidence of dental caries, yellow teeth & twisted
limbs among people of all age groups in India.
31

23. Flooded with Fluoride-G/ water is not
potable
A recent publication of the Geographical Survey of
India (GSI) names areas that should go on fluoride red
alert: Fazilka & Jalalabad in the border district of
Ferozpur in Punjab, parts of Gurgaon, Rewari,
Mahendranath, Hisar, Fatehabad & Faridabad district
in Haryana, Unnao, Rae Barely & Sonebhadra district
in Uttar Pradesh, Sidhi district in Madhya Pradesh,
Beed district in Maharastra, Nalgonda district in
Andhra Pradesh and Dindigul district in Tamilnadu.
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24. • Fluoride effected villages 459
(based on RGNDWM 91)
Range No. of villages
1.5-2 ppm 159
2-2.5 ppm 149
2.5-3 ppm 97
3-4 ppm 40
4-8 ppm 14
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Fluoride
effected Villages

25. •Range of Concentration
1.5-8.4 ppm
•Lower range of Concentration
1.5-2.5 ppm
(about 67% villages)
•Cause- Salt concentration neat
aquifers
•Trend- No. of villages increasing
Reason
(i) Heavy withdrawal of water
from upper strata
(ii)Less charging of Strata due to
Silt/ clayey upper layer of Soil
34
Fluoride
effected Villages

26. How the problem can be
minimized
1 By providing pipe water system with source (electric based)
(a) Surface water
(b) Deep tubewells
2 Recharging stratas through rainwater harvesting
methods
(No. of villages of lower range concentration can be
decreased)
3 Storing rain water for drinking purpose
(a) In areas where electricity problem is more
(b) In areas where concentration is more
© In areas where PWS is uneconomical
(d) In areas where dependable source is not available
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27. Thank You
a presentation by eco
club