"ROOF TOP RAIN WATER HARVESTING" Is the branch "Water Resource Engineering"

1. Department of Civil Engineering
2019-23

2. CERTIFICATE OF
APPROVAL
This is to Certify that the B. TECH Project Report entitled “Roof Top Rainwater
Harvesting” submitted by Md Masoom Alam to Government Engineering
College, Jamui, for the award of the degree of Bachelor of Technology has been
accepted by the external examiners and that the student has successfully
completed the Project work.
EXAMINERS:
(i). Prof. Deep Raj PROJECT GUIDE
(ii). ……………………………………… EXTERNAL EXAMINER
(iii). Prof. Chandrashekhar Kumar HEAD OF THE DEPARTMENT
Government Engineering College, Jamui
(i)

3. CERTIFICATE
This is to certify that the B. TECH Project Report entitled “ROOF TOP
RAINWATER HARVESTING” submitted b
y Civil Engineering student, Md
Masoom Alam to GOVERNMENT ENGINEERING COLLEGE, JAMUI is
a bonafide record of research work carried out by him under our supervision and
is worthy of consideration for the award of degree of Bachelor of Technology of
the
Institute.
Project Guide
Prof. Deep raj
Civil Engineering
Department Government Engineering College,
Jamui Date: / / 2023
Government Engineering College, Jamui

4. DECLARATION
I certify that
(a). The work contained in this B.TECH Project Report is original and
has been done by me under the guidance of my supervisor.
(b). The work has not been submitted to any other Institute for any degree
or diploma.
(c). I have followed the guidelines provided by the Institute in preparing the
B.TECH Project Report.
(d). I have conformed the norms and guidelines given in the Ethical Code of
Conduct of the Institute.
(e). Whenever, I have used materials (data, theoretical analysis, figures, &
text) from other sources, I have given due credit to them by citing them
in the text of the B.TECH Project Report and giving their details in the
references. Furthermore, I have taken permission from the copyright
owners of the sources, whenever necessary.
Md Masoom Alam
(Reg.No- 19101133021)
(iii)

5. ACKNOWLEDGEMENT
It is with a feeling of great pleasure that I would like to express my most
sincere heartfelt gratitude to my Guide Assistant Professor Deep Raj of
Civil Engineering, GOVERNMENT ENGINEERING COLLEGE, JAMUI
for his valuable support, suggestion, admonition, encouragement, advice
and mentoring and throughout my Project work. His technical and
editorial advice was essential for the completion of this project. It is an
inspirational experience while guiding under him.
I would like to express my sincere thanks to Professor Chandrashekhar
Kumar, Hod of civil Department, GOVERNMENT ENGINEERING
COLLEGE, JAMUI for his continuous support, guide and encouragement
for completion of this project.
I am grateful to Prof. Deep raj, Prof Sujit kumar, Prof Chandrashekhar
kumar (HOD), for their technical inputs throughout my research.
I am willing to thanks technician of Rainwater harvesting lab, Hydrology
and water resource Engg, for their experimental support. I would like to
thank the Omnipotent for his blessings.
Last, but not the least, I would like to thank all my B.Tech classmates for
their valuable comments, suggestions and unconditional support.
Md Masoom Alam
(19101133021)
B. Tech (Civil Engineering)
(iv)

6. (v)

7. ABSTRACT
Water is perhaps the most precious asset on earth. It is one of
the five basic elements of nature, the others being air, soil, fire
and space. Fresh water is essential for human survival and
rainfall is its single largest source. The part of rainfall that is
trapped in surface and groundwater sources is all that is available
for human consumption. This is what has come to be known as
Rainwater Harvesting (RWH). So far as rainwater harvesting in
India is concerned, the entire past can be divided in three time
capsules. From (-) infinity upto say, 3000 B.C is the first capsule
and in this time period, rainwater got harvested naturally without
any human intervention, in rivers and natural depressions.
Rivers were the first known secondary source of fresh water. It
was during this period that civilizations flourished on the banks of
rivers not only in India but the world over. Egypt rose on the banks
of Nile, Mesopotamia rose on the banks of Euphrates and Tigris,
Europe on the Danube and China on the Yellow River. In India,
the Harappan civilization flourished on the banks of Ravi and
Mohenjo-Daro on the banks of Indus.
(vi)

8. CONTENTS
Page No.
Abstract ………………………………………………………..… 1
CHAPTER – 1 : INTRODUCTION..
1.1: INTRODUCTION ………………………….…….... 3
CHAPTER – 2 : OBJECTIVES
2:1: AIM & OBJECTIVES.......................................... 5
2:2: RAINWATER HARVESTING ……………….…… 5
2:3: WAYS OF HARVESTING WATER …………..…. 6
2:4: NEED FOR RAINWATER HARVESTING …….. 6
2:5: ADVANTAGES & DISADVANTAGES OF
RAINWATER HARVES ……………………….. 7
CHAPTER – 3 : METHODS OF RAINWATER HARVESTING
3:1: WAYS OF RAIN WATER HARVESTING……… 8
3:2: TECHNIQUE OF RAIN WATER HARVESTING… 8
3:3: BASIC CONCEPONENT ..................................... 9
3:4: CONCEPT OF RAIN WATER HARVESTING… 9
CHAPTER – 4 : DISCUSSION WITH EXPLANATION
4.1: WHY SHOULD I HARVEST RAIN?.................. 11
4.2: PROCESS………………………………………. 12
4:3: RECHARGING THE GROUNG WATER
LEVEL…………………………………………. 13
4:4: IMPLEMENTATION OF RAIN WATER
HARVESTING ………………………………… 14
CHAPTER – 5 : CONCLUSION
5:1: COMPONENTS OF RAINWATER
HARVESTING……………………………….... 17
5:2: CONCLUSION…………………………………. 31
REFERENCE: …………………………………………….…….… 32

9. Rain Water Harvesting
INTRODUCTION
Figure 1 : (Diagramatic design of rainwater harvesting)
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10. INTRODUCTION
Water is perhaps the most precious asset on earth. It is one of the five
basic elements of nature, the others being air, soil, fire and space.
Fresh water is essential for human survival and rainfall is its single
largest source.The part of rainfall that is trapped in surface and
groundwater sources is allthat is available for human consumption.
This is what has come to be known as Rainwater Harvesting
(RWH). So far as rainwater harvesting in India is concerned, the
entire past can be divided into 3-time capsules. From (-) infinity upto
say, 3000 B.C is the first capsule and in this time period, rainwater
got harvested naturally without any human intervention, in rivers
and natural depressions. Riverswere the first known secondary
source of fresh water. It was during this period that civilizations
flourished on the banks of rivers not only in India but the world over.
Egypt rose on the banks of Nile, Mesopotamia rose on the banks of
Euphrates and Tigris, Europe on the Danube and China on the
Yellow River. In India, the Harappan civilization flourished on the
banks of Ravi and Mohenjodaro on the banks of Indus.
(2)

11. CHAPTER - 2
➢
2.1 Aim and Objectives
Aim - Feasibility of rain water harvesting.
Objectives:
o To modify and developed the Rain Water harvesting
system.
o To make aware about our project rainwater harvesting.
o To implement rainwater harvesting in various states of India.
o To explain rainwater harvesting.
o New techniques used in our project rainwater
harvesting- its explanation.
o Where it can be implemented.
➢
2.2 RAIN WATER HARVESTING
o The term Rainwater Harvesting is usually taken to mean the
Immediate collection of rainwater running off surfaces upon
which It has fallen directly. This definition excludes run-off
from landWatersheds into streams, rivers, lakes, etc.
o It includes water that is collected within the
boundaries of aproperty, from roofs and surfaces.
o The Rainwater harvesting is the simple collection or
storing of Water through scientific techniques from the
areas where the rainfalls.
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12. o It involves utilization of rain water for the domestic
or the agricultural purpose.
o The method of rain water harvesting has been into practice
since ancient times.
• Ways Of Harvesting Water
o Capturing run-off from rooftops,
roads.
o Capturing run-off from local
catchments
o Capturing seasonal flood water from local streams.
o Conserving water through watershed management. It
involvesutilization of rain water for domestic or agricultural
purpose.
• Need for Rain Water Harvesting
Most of the rain falling on the surface tends to flow away rapidly,
leaving very little for the recharge of groundwater. As a result, most
parts of India experience lack of water even for domestic uses.
Hence, the need for implementation of measures to ensure that rain
falling over a region is tapped as fully as possible through rainwater
harvesting, either by recharging it into the groundwater aquifers or
storing it for direct use. In desert, where rainfall is low, rainwater
harvesting has been providing relief to people.
➢
2.5. Advantages of Rain Water Harvesting
o Reduces Flooding and Erosion.
o Reduces Water Bills.
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13. o Reduces Demand on Ground Water.
o Can Be Used for Non-drinking Purposes.
o Can Improve Plant Growth.
• Disadvantage of Rain Water Harvesting
o Supplies can be contaminated by bird/ animal
droppings on catchment surfaces and guttering
structures unless they are cleaned / flushed before us.
o Poorly constructed water jars/containers can
suffer from algalgrowth and invasion by insects,
lizards and rodents.
o They can act as a breeding ground for disease
vectors if they arenot properly maintained.
(5)

14. CHAPTER – 3
➢
3.1: Ways of Harvesting Rainwater
• SURFACE RUNOFF HARVESTING: It is a method in
which rainwater flowing as surface runoff is caught and used for
recharging aquifers by adopting appropriate methods.
• ROOF TOP RAINWATER HARVESTING (RTRWH): In
rooftop harvesting, the roof becomes the catchment, and the
rainwater is collected from the roof of the house/building. It can
either be stored in a tank or diverted to artificial recharge system.
➢
3.2 Techniques of Rain Water Harvesting:
1). Storage of rainwater on surface for future use: The
storage of rain water on surface is a traditional technique and structures
used were underground tanks, ponds, check dams,weirs etc.
2). Recharge to ground water: The collected rainwater is
transferred to the ground through suitable means for
rechargingthe depleting aquifers.
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15. ➢
3.3 Basic Components
Figure 2: - (Basic Components)
➢
3.4 CONCEPT OF RAINWATER HARVESTING
o Rainwater harvesting might be the collection of rainwater
from a surface that allows for the rainwater to be stored
and used at alater time. In a typical rainwater harvesting
situation, rainwater is collected from an impervious surface
such as the roof of a building and then stored inside of a
tank or cistern. Rainwater can be collected from other
surfaces as well.
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16. Other surfaces include parking lots, roadways, driveways, and
even land surfaces (once surface runoff from the land surface
begins).
o Rainwater can be harvested and stored for many uses
including landscape irrigation, potable and no potable
indoor use, and storm water management. Harvested
rainwater can be particularly useful when no other source
of water supply is available, or if the available supply is
inadequate or of poor quality. Rainwater harvesting has
benefits for both urban (where municipal water is
available) and rural properties (where a water well is
employed). The practice of rainwaterharvesting ranges
from simple ideas such as a rain barrel set up underneath
a gutter downspout to complex systems such as for
commercial buildings or systems that supply the portable
water for a house.
(8)

17. CHAPTER – 4
➢
4.1 WHY SHOULD I HARVEST RAIN ?
oRainwater harvesting is becoming popular once again for two
reasons: its superior water quality and a desire to reduce the
use and dependence on municipally treated water for all of
our daily uses. Rainwater has long been valued for its purity
and softness.
oIt is free from salts, minerals, and other natural and man-made
contaminants. In addition, rainwater harvesting is valued as
a water conservation tool since it allows you to use rainwater
instead of municipally treated water. This, in turn, reduces
the amount of water amunicipality has to treat and deliver to
their service area.
o Rainwater is essentially FREE; once the capital cost of
the collection system infrastructure is paid for, you will
harvest free water.
o It is socially acceptable and environmentally responsible
since it promotes self-sufficiency and helps conserve
water.
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18. o It reduces your municipal water consumption and thus your
waterbill.
o It can be used as a main source of water or as a back-up
source towells and municipal water. It can also be very
helpful in times of emergencies.
o Rainwater harvesting systems can be easily retrofitted to an
existing structure or built during new home construction. They are
very flexible and modular in nature, allowing expansion,
reconfiguration, or relocation.
o Rainwater is the best water source for landscape irrigation
due to the lack of chlorine and other treatment
chemicals.
o Rainwater harvesting can reduce the frequency and
intensity offlooding around your house or property.
o Since the use of the harvested water is located close to
the collection source, this reduces the energy use
required to movewater around our cities.
o Rainwater harvesting can reduce storm water pollution,
lesseningits impact on our local watersheds.
➢4.2 PROCESS
A rainwater harvesting system has three main stages:
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19. 1. Collecting & transporting rainwater: This is done
through catchment areas & conduits. The catchment of a
water harvestingsystem is the surface which receives rainfall
directly. It can be a paved area like the terrace or courtyard of
a building. Conduits are the pipelines that carry rainwater from
the catchment or rooftop tothe harvesting system.
2. Filtration: A filter unit is a chamber filled with filtering media to
remove debris and dirt from water before it enters the storage
tankor recharge structure.
3. Storage in tanks for reuse / Recharging the
groundwater:
Levels: The harvested water can now be stored in storage
tanksfor immediate usage, which are designed according to
the waterrequirements of the society. Existing non-potable
water storage tanks in the society can also be used to store
the harvested rainwater.
➢4.3 Recharging the groundwater levels:
o The collected rainwater can also be used to recharge the
groundwater levels by using structures like dug wells, bore wells,
recharge trenches andrecharge pits.
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20. ➢ 4.4 IMPLEMENTATION OF RAIN WATER
HARVESTIN:-
Rainwater harvesting (RWH) system is a technology that
focuses onsustainability and support the sustainable
environment development.The implementation of RWH
systems provides many environments and financial benefits.
Some of the environment benefits of RWH system are the
reduction of surface runoff, reduce the burden of soil aquifer,
and provide the availability of clean water. This study
analysed the RWH system implementation benefits both in
environment and financial side.
The financial benefits of RWH system implementation are
calculated based on a number of rainwaters that can be used
to replace the need forclean water.
The environment benefits defined by the reduced of main
water tap use and the reduced of generated roof runoff
volume. This study used a simple RWH system that uses the
roof as a catchment area, the pipeline as a distribution system,
and tank as the storage system. The water use isfor domestic
potable and no potable for a household with up to four
occupants in Bandung.
(12)

21. The catchment area is taken 70 m2. A water balance model
forvarious scenarios was developed to calculate the algorithm
of the system. The costs taken in RWH system include the
construction, installation, maintenance and operational costs.
The analysis shows that the implementation of RWH systems
provides advantages over the use of conventional systems. It
can save clean water use up to 54,92% and provide runoff
reduction up to 71,53%. RWH system applied requires
additional costs approximately only 0,66% from the value of
the house. It was found that it is possible to achieve payback in
RWH system implementation under several scenarios.
❖
The benefits of rainwater harvesting system are listed below.
1) Less cost.
2) Helps in reducing the water bill.
3) Decreases the demand for water.
4) Reduces the need for imported water.
5) Promotes both water and energy conservation.
6) Improves the quality and quantity of groundwater.
7) Does not require a filtration system for landscape irrigation.
(13)

22. 8) This technology is relatively simple, easy to install and operate.
9) It reduces soil erosion, storm water runoff, flooding, and
pollutionof surface water with fertilizers, pesticides,
metals and other sediments.
10) It is an excellent source of water for landscape irrigation
with no chemicals and dissolved salts and free from all
minerals.
(14)

23. CHAPTER - 5
1. ROOFTOP:
Fig 3: (google pictures on rooftop)
Rooftop rainwater harvesting technologies, according
to the UNFCCC, are rainwater harvesting system that
is a simple technology that promotes sustainable
rainwater management and uses the roof as a
catchment. The system comprises of three (3) basic
elements such as catchment area (represented by the
roof), conveyance system (gutters), and storage (tank).
An example of a rooftop rainwater harvesting system.
2. IN SITU:
The in situ technology is a method where the storage
of collected rainwater in a direct way is utilized
immediately.For example, in arid and semiarid regions,
the storage for the maximum amount of rainwater
during the wet season is made for use at a later time
(15)

24. when rain is low during the dry season, especially for
agricultural and domestic water supply.
This technique as other rainfall harvesting systems has
three components: a collection conveyance system,
anda storage area.
An example of in situ rainwater harvesting used in the
arid andsemiarid regions of North-eastern Brazil and
Paraguay is primarily for irrigation purposes.
3. SURFACE WATER:
Figure 4: (google pictures)
Surface water is water on the surface found on
wetlands that is no saline and is replenished by one of the
processes in the hydrologic cycle—precipitation. The
surface water supports the replacement of groundwater
aquifer supply if it channelled efficiently.
(15)

25. In most urban areas, the surface water is wasted and
polluted. The wasting can be mitigated with proper
utilization of surface water from rain via rainwater
harvesting and storing it into the aquifer.
4. GROUNDWATER RECHARGE:-
Groundwater recharge is a process where groundwater is
supported by several techniques to add or bring back the
health of the groundwater for sustainability. It can be
upstream or downstream discharge such as areas close to
mountain peaks because the precipitation is higher than in
the adjacent lowlands.
5.1: Components of Rainwater Harvesting system
A rainwater harvesting system comprises components of various
stages – transporting rainwater through pipes or drains, filtration,
andstorage in tanks for reuse or recharge. The common
components of arainwater harvesting system involved in these
stages are illustrated here.
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26. 1. Catchments: -
The catchment of a water harvesting system is the surface which directly
receives the rainfall and provides water to the system. It can be a paved
area like a terrace or courtyard of a building, or an unpaved area like a lawn
or open ground. A roof made of reinforced cement concrete (RCC),
galvanised iron or corrugated sheets can also be used for water harvesting.
2. Coarse mesh at the roof to prevent the passage of debris:
Gutters (optional) – Refers to the channels created along the perimeter of
the catchment area to transport rainwater
3. Gutters: -
Channels all around the edge of a sloping roof to collect and transport
rainwater tothe storage tank. Gutters can be semi-circular or
rectangular and could be made using:
1) Locally available material such as plain galvanised iron sheet (20
to 22 gauge),folded to required shapes.
2) Semi-circular gutters of PVC material can be readily prepared by
cutting thosepipes into two equal semi-circular channels.
3) Bamboo or betel trunks cut vertically in half.
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27. .
The size of the gutter should be according to the flow during the
highest intensityrain. It is advisable to make them 10 to 15 per
cent oversize.
Gutters need to be supported so they do not sag or fall off when
loaded with water.The way in which gutters are fixed depends on
the construction of the house; it is possible to fix iron or timber
brackets into the walls, but for houses having wider eaves, some
method of attachment to the rafters is necessary.
4). Conduits
Conduits are pipelines or drains that carry rainwater from the
catchment or rooftop area to the harvesting system. Conduits
can be of any material like polyvinyl chloride(PVC) or
galvanized iron (GI), materials that are commonly available.
The following table gives an idea about the diameter of pipe required
for draining outrainwater based on rainfall intensity and roof area:
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28. • Sizing of rainwater pipe for roof drainage
Diameter
Of
Pipe(mm)
Average rate of rainfall in
mm/h
50 75 100 125 150 200
50 13.4 8.9 6.6 5.3 4.4 3.3
65 24.1 16.0 12.0 9.6 8.0 6.0
75 40.8 27.0 20.4 16.3 13.6 10.2
100 85.4 57.0 42.7 34.2 28.5 21.3
125 - - 80.5 64.3 53.5 40.0
150 - - - - 83.6 62.7
mm/ h - millimeters per hour; m - meters
Source: National Building Code
5. First-flushing: -
A first flush device is a valve that ensures that runoff from the
first spell ofrain is flushed out and does not enter the system.
This needs to be done since the first spell of rain carries a
relatively larger amount of pollutants from the air and catchment
surface.
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29. 6. Filter:-
The filter is used to remove suspended pollutants from rainwater
collected over roof. A filter unit is a chamber filled with filtering media
such as fiber, coarse sand and gravel layers to remove debris and dirt
from water before it enters the storage tank or recharge structure.
Charcoal can be added for additional filtration.
(i). Charcoal water filter:
A simple charcoal filter can be made in a drum or an earthen pot.
Thefilter is made of gravel, sand and charcoal, all of which are easily
available.
(ii). Sand filters:
Sand filters have commonly available sand as filter media. Sand filters are
easy and inexpensive to construct. These filters can be employed for
treatment of water to effectively remove turbidity (suspended particles like
silt and clay), colour and microorganisms.
In a simple sand filter that can be constructed domestically, the top layer
comprises coarse sand followed by a 5-10 mm layer of gravel followed by
another 5-25 cm layer of gravel and boulders.
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30. (ii). A). Dewas filters:
Most residents in Dewas, Madhya Pradesh, have wells in their
houses.Formerly, all that those wells would do was extract
groundwater. But then, the district administration of Dewas initiated
a groundwater recharge
scheme. The rooftop water was collected and allowed to pass
through afilter system called the Dewas filter, designed by Mohan
Rao , district collector of Dewas, and engineers of the rural
engineering services. Thewater thus filtered is put into the service
tube well.
The filter consists of a polyvinyl chloride (PVC) pipe 140 mm in
diameterand 1.2m long. There are three chambers. The first
purification chamberhas pebbles varying between 2-6 mm, the
second chamber has slightly larger pebbles, between 6 and 12 mm
and the third chamber has the largest - 12-20 mm pebbles. There
is a mesh at the outflow side throughwhich clean water flows out
after passing through the three chambers.
The cost of this filter unit is Rs 600.
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31. Fig 5: (sketch diagram of dewas filter)
Filter for large rooftops:
When rainwater is harvested in a large rooftop area, the filtering
system should accommodate the excess flow. A system is
designed with three concentric circular chambers in which the
outer chamber is filled with sand, the middle one with coarse
aggregate and the inner-most layer with pebbles.
This way the area of filtration is increased for sand, in relation to
coarse aggregate and pebbles. Rainwater reaches the Centre
core and is collected in the sump where it is treated with few
tablets of chlorine and is made ready for consumption. This
system was designed by
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32. ➢Varun:
S Vishwanath, a Bangalore water harvesting expert, has
developeda rainwater filter "VARUN". According to him, from a
decently clean roof 'VARUN' can handle a 50 mm per hour
intensity rainfall from a 50 square meter roof area. This means
the product is relatively standardized. For new house builders
we therefore can recommendthe number of downpipes they
have to optimize on and the number of filters they will need.
‘VARUN' is made from a 90-liter High Density Poly Ethylene
(HDPE) drum. The lid is turned over and holes are puched in it.
This is the firstSieve which keeps out large leaves, twigs etc.
Rainwater coming out of the lid sieve then passes through three
layers of sponge and a 150
mm thick layer of coarse sand. Presence of sponge makes the
cleaningprocess very easy. Remove the first layer of sponge and
soak /clean it in a bucket of water (which you then don't waste but
use it for plants).
The sand needs no cleaning at all. The basic cost of the filter is
aboutRs 2250/-Book Detail.
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33. (ii). B. Horizontal roughing filter and slow sand filter:
The introduction of horizontal roughing filter and slow sand
filter (HRF/SSF) to treat surface water has made safe
drinking water available in coastal pockets of Orissa. The
major components ofthis filter are described below.
1). Filter channel: One square meter in cross-section and eight m in
length, laid across the tank embankment, the filter channel
consists of three uniform compartments, the first packed with
broken bricks, the second with coarse sand, followed by fine sand
in the third compartment. The HRF usually consists of filter
material like gravel and coarse sand that successively decreases
in size from 25 mm to 4mm. The bulk of solids in the incoming
water is separated by this coarse filter media or HRF. At every
outlet and inlet point of the channel, fine graded mesh is
implanted to prevent entry of finer materials into the sump. The
length of a channel varies according to the nature of the site
selected for the sump.
2). Sump: A storage provision to collect filtered water from the tank
throughthe filter channel for storage and collection.
While HRF acts as a physical filter and is applied to retain
solid matter, SSF is primarily a biological filter, used to kill
microbes inthe water. Both filter types are generally stable,
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34. makingfull use of the natural purification process of harvested
surface water and do not require any chemicals.
Recharge structures:
Rainwater may be charged into the groundwater aquifers
through any suitable structures like dugwells, borewells,
recharge trenches and recharge pits.
Various recharge structures are possible - some which promote
the percolation of water through soil strata at shallower depth
(e.g., recharge trenches, permeable pavements) whereas others
conduct water to greater depthsfrom where it joins the
groundwater (Ex. Recharge wells).
At many locations, existing structures like wells, pits and tanks
can be modified as recharge structures, eliminating theneed to
construct any structures afresh. Here are a few commonly used
recharging methods:
1. Recharging of dugwells and abandoned tubewells.
In alluvial and hard rock areas, there are thousands of wells
which have either gone dry or whose water levels have declined
considerably. These can be recharged directly with rooftop run-
off. Rainwater that is collected on the rooftop of the building is
diverted by drainpipes to a settlement or filtration tank, from which
it flows into the recharge well (Borewell or dugwell). If a tube well
is used for recharging, then the casing (outer pipe) should
preferably be a slotted orperforated pipe so that more surface
area is available for thewater to percolate.
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35. Developing a borewell would increase its recharging capacity
(Developing is the process where water or air is forced into the well
under pressure to loosen the soil strata surrounding the bore to
make it more permeable).
If a dugwell is used for recharge, the well lining should have
openings (weep-holes) at regular intervals to allow seepage of
water through the sides. Dugwells should be covered to prevent
mosquito breeding and entry of leaves and debris. The bottom of
recharge wells should be desilted annually to maintain the intake
capacity.
Providing the following elements in the system can ensure the quality
of water entering the recharge wells:
1. Filter mesh at entrance point of rooftop drains
2. Settlement chamber
3. Filter bed
A settlement chamber to collect the runoff from paved or unpaved
areas draining out of a compound, recharge troughs are commonly
placed at the entrance of a residential/institutional complex.
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36. These structures are similar to recharge trenches except for the
fact that the excavated portion is not filled with filter materials.
In order to facilitate speedy recharge, boreholes are drilled at
regular intervals in this trench. In design part, there is no need of
incorporating the influence of filter materials.
This structure is capable of harvesting only a limited amount of
runoff because of the limitation with regard to size.
Book Detail
8. Modified injection well:
In this method water is not pumped into the aquifer but allowed
to percolate through a filter bed, which comprises sand and
gravel. A modified injection well is generally a borehole, 500
mm diameter, which is drilled to the desired depth depending
upon the geological conditions, preferably 2 to 3 m below the
water table in the area. Inside this hole a slotted casing pipe
of 200 mm diameter is inserted. The annular space between
the borehole and the pipe is filled with gravel and developed
with a compressor till it gives clear water. To stop the
suspended solids from entering the recharge tube well,
a filter mechanism is provided at the top.
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37. CONCLUSION
This project rainwater harvesting has given me many benefit from
using group work as part of teaching and learning
activities in this project. Working in teams can make work a
lot more easily leading to an involving and satisfying experience
for students. By engaging myself into a group, I increased my
involvement in the project, put in more effort, gained greater
satisfaction and became more oriented in completing the group’s
task. Also, working in groups can be challenging at times and it
demands a set of skills. With this project, gained
fair knowledge about the way task-oriented groups work and what
complexity it involves. At first, it was hard for me to understand
the Whole process of team work and the amount
of communication skills it involved but by undertaking this project
in groups, I have certainly developed a stronger sense
of obligation amongst the members and increased pressure
towards the completion of the task.
Demand for water supply increases, especially in urban areas,
due to the constantly increasing level of urbanization and
industrialization. This is leading to overuse of groundwater and
thus, lower levels.
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38. TERMINOLOGY IN RAIN WATER HARVESTING
Rainwater Harvesting:- Rainwater harvesting is the simple process
or technology used to conserve rainwater by collecting staring, conveying
and purifying of rainwater that runs off from rooftops, parks, roads,
open grounds, etc.
Catchment :- Used to collect and store the captured rainwater.
Conveyance System:- It is used to transport the harvested water from
the catchment to the recharge zone.
Flush:- It is used to flush out the first spell of rain.
Filter:- Used for filtering the collected rainwater and removing pollutants.
Tanks and recharge structures :- Used to store the filtered water which
is ready to use.
Runoff:- The falling rain hits a surface and flows off it. This component is
the runoff.
Aquifer:- The water reserves below ground are contained in sand,
gravel, permeable rocks, rock fissures and this constitutes the aquifer.
In the United States, some notable aquifers are the Edwards aquifer
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39. in Central Texas, the Ogallala aquifer in central United States which
spans across portions of eight states.
Recharge: The movement of water from the surface to deeper ground is
called Recharge. Recharge can be both natural and artificial through
human intervention. Recharge is extremely important towards sustainable
ground water management.
Withdrawal:- The term withdrawal in the context of groundwater is the
process of extraction of ground water from the aquifer.
Groundwater overdraft:- When the volume rate of withdrawal of ground
water exceeds the volume rate of recharge, groundwater overdraft occurs
and is quantified by the difference between extraction and recharge.
For example, in a given year, the total ground water extraction from an
aquifer is 1000 m3 while the recharge is only 500 m3. The annual ground
water overdraft in this case is 500 m3.
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40. ➢ REFERENCECE
1). WaterAid India. (2021). Rainwater Harvesting. Retrieved
from https://www.wateraidindia.in/what-we-do/water-sanitation
-and-hygiene/rainwater-harvesting
2). Census of India. (2011). Census Data Online: Population
Enumeration Data (Final Population). Retrieved from
https://censusindia.gov.in /2011census/population_
enumeration.html
3). Ministry of Jal Shakti, Government of India. (2021). National
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20Water%20Policy.pdf
4). Kahinda, J.M. Lillie, E.S.B. Taigbenu, A.E. Taute, M.
Boroto, R.J., (2008). Developing suitability maps for
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Phys. Chem. Earth Parts A/B/C, 33,
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5). Rainwater Harvesting and Reuse: A Study on Sustainable
Water Management Practices in Chennai, India. International
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1269.
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41. 6). Ganesan, V., & Muthu Kumar, S. (2018). Performance
Evaluation of Rooftop Rainwater Harvesting System in Tamil
Nadu, India. Water Resources Management, 32(1), 337–351.
https://doi.org/10.1007/s11269-017-1801-y
7). Krishnamurthy, V. (2014). Assessment of Rainwater
Harvesting Potential for Domestic Water Supply in
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https://doi.org/10.1016/j.jhydrol.2014.09.028
8). Singh, S. P., & Sinha, D. K. (2018). Rainwater
Harvesting as an Alternate Source of Drinking Water in
Rural India: A Review. International Journal of Current
Microbiology and Applied Sciences, 7(2), 1598–1611.
9). Krishnan, P., Srivastava, R. K., & Srivastava, A. (2017).
Urban Rainwater Harvesting: A Promising Solution to
Water Scarcity in Indian Cities. Water Resources
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https://doi.org/10.1007/s11269-017-1807-5
10). Jayakumar, P., Panchangam, S. C., & Kumar, P. S.
(2018). Assessment of Groundwater Recharge Potential
through Rainwater Harvesting in Urban Areas of India: A
Review. Groundwater for Sustainable Development, 7,
219–229. https://doi.org/10.1016/j.gsd.2018.02.006
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42. 11). United Nations. (2018). Sustainable Development Goal 6:
Ensure Availability and Sustainable Management of
Water and Sanitation for All. Retrieved from
https://www.un.org/sustainabledevelopment/water-and-
sanitation/
12). Agarwal, A., Tiwari, A. K., & Swami, D. (2019). Rainwater
Harvesting: A Tool for Sustainable Development in India.
International Journal of Engineering and Advanced
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13). "Rainwater Harvesting for Livestock". www.ntotank.com.
Retrieved 2018-11-21.
14). "Rainwater Harvesting - Controls in the Cloud".
SmartPlanet. 2013-10-03. Retrieved 11 January 2015.
o https://en.m.wikipedia.org/wiki/Rainwater_harvestin
g
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4
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43. THANK YOU
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