Water Shortage is a topic which is not restricted to India alone but its a global issue now.Rainwater harvesting is a technique of collection and storage of rainwater into natural reservoirs or tanks, or the infiltration of surface water into subsurface aquifers (before it is lost as surface runoff). One method of rainwater harvesting is rooftop harvesting.

1. Presentation by: Achint Jindal (IT- Branch)
Project Guide: Dr. Tanuja Nautiyal

2. Contents
Introduction
Concept and Technology of Rainwater Harvesting
Average Rainfall of States in India
Availability of Rainwater Through Roof Top Rainwater Harvesting
Runoff Coefficients for Various Catchments Surfaces
Rainwater Harvesting System
Treatment Techniques
Rainwater Harvesting System at Siel Chemical Complex

3. Every year, the water level in the state PUNJAB
goes down by one meter. If this continues, the state
will soon turn into a desert. So it is necessary to
save every drop of water.
“Every commercial building as well as big houses in
the state must install Rain water harvesting system
to save water”
Introduction

4. 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. Rain Water in India
 Total annual rainfall in India: 400 million hectare-
meters (area x height)
 India’s area: 329 million hectares
 If evenly spread, average height: 1.28m
 Actual distribution:
 Highly skewed area-wise
 The desert receives less than 200mm annually,
while Cherrapunji receives 11,400mm
 But almost every part of India receives at least
100mm annually
 Key: even 100mm annual rainfall sufficient if
harvested properly and where it falls

6. But….
 Temporal distribution of rain in India also skewed
 Rainfall in India seasonal (unlike Western countries)
 Most of the country receives rainfall only for about
100 hours each year
 Rough rule of thumb: #cm of rain = #hours rain
received
 E.g.: Jodhpur receives 40cm of rain in about 40
hours
 Natural implication of such skew:
 Most of the rain water lost due to runoffs
 Unlike the west, very little water percolates into
the ground
 Hence, the importance of harvesting structures for
local self-sufficiency

7. Sl.No. State Meteorological Divisions
Average annual
rainfall (mm)
1
Andaman and
Nicobar Andaman and Nicobar Islands 2,967
2
Arunachal
Pradesh Arunachal Pradesh 2,782
3 Assam Assam and Meghalaya 2,818
4 Meghalaya Assam and Meghalaya 2,818
5 Nagaland Nagaland, Manipur, Mizoram an Tripura 1,881
6 Manipur Nagaland, Manipur, Mizoram andTripura 1,881
7 Mizoram Nagaland, Manipur, Mizoram andTripura 1,881
8 Tripura Nagaland, Manipur, Mizoram andTripura 1,881
9 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
Average Rainfall of States in India

8. Sl. No. State Meteorological Divisions
Average annual
rainfall (mm)
11 Orissa Orissa 1,489
12 Bihar
Bihar Plateau 1,326
Bihar Plains 1,186
13 Uttar Pradesh
Uttar Pradesh 1,025
Plain of West Uttar Pradesh 896
Hills of West Uttar Pradesh 1,667
14 Haryana Haryana, Chandigarh and Delhi 617
15 Delhi Haryana, Chandigarh and Delhi 617
16 Chandigarh Haryana, Chandigarh and Delhi 617
17 Punjab Punjab 649
18 Himachal Pradesh Himachal Pradesh 1,251
19
Jammu and
Kashmir Jammu and Kashmir 1,011
20 Rajasthan
West Rajasthan 313
East Rajasthan 675

9. Sl. No. State Meteorological Divisions
Average annual
rainfall (mm)
21 Madhya Pradesh
Madhya Pradesh 1,017
East Madhya Pradesh 1,338
22 Gujarat
Gujarat region 1,107
Saurashtra and Kachchh 578
23 Goa Konkan and Goa 3,005
24 Maharashtra
Konkan and Goa 3,005
Madhya Maharashtra 901
Marathwada 882
Vidarbha 1,034
25 Andhra Pradesh
Coastal Andhra Pradesh 1,094
Telengana 961
Rayalaseema 680
26 Tamil Nadu Tamil Nadu and Pondicherry 998
27 Pondicherry Tamil Nadu and Pondicherry 998
28 Karnataka
Coastal Karnataka 3,456
North Interior Karnataka 731
South Interior Karnataka 1,126
29 Kerala Kerala 3,055
30 Lakshadweep Lakshadweep 1,515

10. Why Rain water harvesting
 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

11. Concept and Technology of Rainwater Harvesting
Rainwater is a free source of nearly pure water and rainwater
harvesting refers to collection and storage of rainwater and other
activities aimed at harvesting surface and ground water. It also
includes prevention of losses through evaporation and seepage and
all other hydrological and engineering interventions, aimed at
conservation and efficient utilization of the limited water. In general,
water harvestings the activity of direct collection of rainwater. The
rainwater collected can be stored for direct use or can be recharged
into the ground water.
There are two main techniques of rain water harvestings.
 Storage of rainwater on surface for future use.
 Recharge to ground water.

12. Rain
Roof Top
Filtration
or
Recharge to ground water
Storage
Rooftop Water

13. Technology of Rainwater Harvesting

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

15. Water available from Roof = Annual rainfall (in mm) x roof area (in
sq. m) x co-efficient of run off for roof
Suppose the system has to be designed for meeting drinking water
requirement of a 5-member family living in a building with a
rooftop area of 100 sq.m. Average annual rainfall in the region is
600 mm. Daily drinking water requirement per person (drinking
and cooking) is 10 liters.
We shall first calculate the maximum amount of rainfall that can
be harvested from the rooftop .Following details are available:
Area of the catchments (A) = 100 sq.m.
Average annual rainfall (R) = 600 mm (0.6 m)
Runoff coefficient (C) = 0.85
Annual water harvesting potential from 100 sq.m. roof
= A x R x C
= 100 x 0.6 x 0.85
= 51 cu.m. (51,000 ltr)
Availability of Rainwater Through Roof Top
Rainwater Harvesting

16. The tank capacity has to be designed for the dry period, i.e., the
period between the two consecutive rainy seasons.
With the rainy season extending over four months, the dry season
is of 245 days. Particular care must be taken to ensure that
potable water is not contaminated by the collected rainwater.
Drinking water requirement for the family
(dry season) = 245 x 5 x 10
= 12,250 ltr.
As a safety factor, the tank should be built 20 per cent larger than
required, i.e., 14,700 ltr. This tank can meet the basic drinking
water requirement of a 5-member family for the dry period.

17. All rainwater-harvesting systems comprise six basic
components irrespective of the size of the system.
1. Catchments area/roof: The surface upon which the rain falls; the
roof has to be appropriately sloped preferably towards the
direction of storage and recharge.
2. Gutters and downspouts: The transport channels from
catchments surface to storage; these have to be designed
depending on site, rainfall characteristics and roof characteristics.
3. Leaf screens and roof washers: The systems that remove
contaminants and debris; a first rain separator has to be put in
place to divert and manage the first 2.5 mm of rain.
4. Storage tanks: Sumps, tanks etc. where collected rain-water is
safely stored or recharging the ground water through open wells,
bore wells or percolation pits etc.
5. Conveying: The delivery system for the treated rainwater, either
by gravity or pump;
6. Water treatment: Filters to remove solids and organic material
and equipment, and additives to settle, filter, and disinfect.

18. Rain Water Distribution & Management

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

20. 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

21. Rainwater Harvesting System at
Siel Chemical Complex

22. Rainwater Harvesting System at
Siel Chemical Complex
SIEL Chemical Complex is a Caustic Soda production plant located at
Rajpura. It has ISO 14000 certification and the organization is very much
concerned to improve the Environmental standards within and outside
the premises of company. To improve the Ground water level in the
surrounding areas, organization is trying to implement the Rain Water
Harvesting within the premises.
In SCC, we are having 02 nos units of rain water harvesting . The first
unit of rain water harvesting was installed and taken in operation w.e.f.
July 20,2007.
It is estimated that around 500m3 of water will be charged into the ground
in a year, with an average rainfall of 82 cms .

23. Rainwater Harvesting System at
Siel Chemical Complex
Here we are considering the only Rooftop of A & PO building, Security
block building and HR and Administrative block building for rainwater
harvesting.
Rooftop area of A&PO building = 304 sq. m.
Rooftop area of security block building = 192 sq. m.
Rooftop area of HR and administrative block building = 662 sq. m.
Total Rooftop Area = 1158sq.m.
Average Rainfall in this region = 82.23 cm.
= .82 m.
Assuming that 60% of total rainfall is effectively harvested.
Volume of water harvested = 1158 X .82 X .6 cu. m.
= 569.736 cu. m.
= 569736 ltr.
So we can save 569 m3. of water annually from above said building

24. THANK YOU