This document provides an overview of rainwater harvesting in India. It discusses that rainwater harvesting means capturing rainwater where it falls through direct collection or catchment runoff. It provides average annual rainfall amounts for various states in India. It describes techniques for rainwater harvesting including storage on surface and groundwater recharge. Components of rainwater harvesting systems are outlined including the roof, gutters, tanks, filters and treatment. Materials used for rainwater tanks are also mentioned. The importance of rainwater harvesting for water conservation and reducing depletion is highlighted.

1. Presented by
MD FAIZ ALI
13U61A0104

2. contents Introduction.
 Concept and Technology.
 Average Rainfall of States in India.
 Runoff Coefficients for Various Catchments Surfaces.
 Rainwater Harvesting System.
 Treatment Techniques.
 Materials for Rainwater Tanks.
 Components of Rainwater harvesting.
 Conclusion.

3. WHAT IS water harvesting ?
It is the activity of direct collection of
rain water .
Water harvesting means capturing rain
water, where it falls and capture the
runoff from, catchment and streams etc.
Generally, water harvesting is direct
rainwater collection. This collected
water could be stored for later use and
recharged into the ground water again.

4. Rain Water in India
Total annual rainfall in India:
(area x height)
India’s area:329 million
hectares
If evenly spread, average
height: 1.28m
329 X 1.28 = 421.12millimiters

5. Average Rainfall in India
Sl.N
o
States Meteorological Divisions A A R (mm)
01
Andaman and
Nicobar Andaman and Nicobar Islands 2,967
02 Arunachal Pradesh Arunachal Pradesh 2,782
03 Assam Assam and Meghalaya 2,818
04 Meghalaya Assam and Meghalaya 2,818
05 Nagaland
Nagaland, Manipur, Mizoram an
Tripura 1,881
06 Manipur
Nagaland, Manipur, Mizoram and
Tripura 1,881
07 Mizoram
Nagaland, Manipur, Mizoram and
Tripura 1,881
08 Tripura
Nagaland, Manipur, Mizoram and
Tripura 1,881
09 West Bengal
Sub-Himalayan West Bengal and
Sikkim 2,739
Gangetic West Bengal 1,439
10 Sikkim
Sub-Himalayan West Bengal and
Sikkim 2,739

6. WHY WATER HARVESTING IS IMPORTANT
?
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

7. Techniques of rain water harvestings.
There are two main techniques
of rain water harvestings.
Storage of rainwater on surface for future use.
Recharge to ground water.

8. Rain
RAIN WATER HARVESTING
Roof Top
Filtration
Storage
Recharge to ground water

9. Technology for Rain water Harvesting

10. Example of Small level Rain Water harvesting in villages in India

11. Rain Water Distribution &
Management

12. Masonry Tanks
Reinforced Cement Concrete Tank
(RCC)
Ferro Cement Jars
 Pot shaped container:
 Ferro cement Tank using
Skeletal Cage

13. Pot shaped
container
Ferro Cement
Jars
RCC Tank
Masonry Tank
FTSC Tank

14. Determine Tank Capacity
For Rectangular Tank
Height x Length x Width =
Cubic Feet x 7.47 = Gallons
Round Tank
π × R² × H=
Cubic Feet x 7.47 = Gallons

15. Determine the Amount of rainfall
The volume of water
collected in the pan
is:
V (m3) = L (m) x w (m) x d (m) =
1 m x 1 m x 0.010 m = 0.01 m3 or
10 liters
10 mm rainwater collected
in the container

16. Treatment Techniques
Screening
Methods Location Results
Strainers and
Leaf Screens
Gutters and
Leaders
Prevent
leaves and
other
debris from
Settling
Sedimentatio
n
Within Tank Settles
particulate
matter

17. Filtering
In-line/Multi-Cartridge
•Activated Carbon
•Reverse Osmosis
•Mixed Media
•Slow Sand
After Pump
At Tap
At Tap
Separate Tank
Separate Tank
Sieves sediment
Removes chlorine
Removes contaminants
Traps particulate matter
Traps particulate matter
Disinfecting
Boiling/Distilling
Chemical
Treatments
Ultraviolet Light
Ozonation
Before use
Within tank
After the
activated
carbon filter
•Before Tap
Kills microorganisms
Kills microorganisms
Kills microorganisms
Kills microorganisms

18. Components of a Rainwater Harvesting System
 The Roof
 Gutters
 Gutter Guard
 Downspouts
 Debris Traps
 Final Sediment Filtration
 First Flush Diverter
 Surge/Pump Tank
 Water Storage
 Water Disinfection
 Design & Maintenance

19. Catchment
Gutter
Down take Pipe
Storage
Delivery Pipe
First Flush
Filter
Cloud
Rain Fall

20. Materials for Rainwater Tanks
Plastic:
Plastic Liner:
Polyethylene:
Metal:

21. The earth has an abundance of water, but unfortunately only
a small percentage (about 2.5%) is even usable by humans.
The other 97.5% is in the oceans, soils, icecaps, and floating in
the atmosphere.
Earth contains as
Sea+Oceans = 96.5%
Ground water = 1.7%
Glaciers = 1.7%
Vapor+Air = 0.001%
Only 2.5% of this water is freshwater.
Finally its very important to serve everything on
this planet

22. THANK YOU