RAIN WATER HARVESTING
A thesis submitted in the partial fulfillment of the requirements for the
Degree of
BACHELOR OF TECHNOLOGY
IN
CIVIL ENGINEERING
BY
S.NO
REGD.NO
1
2
3
4
5
19981A0105
19981A0110
20985A0101
20985A0110
20985A0113
NAME
B.chaitanya kumar
G.dinesh kumar
A.shanmukha
G.mouli
K.sai
Under the guidance of
Asst.prof M.Krishna sumanth
RAGHU ENGINEERING COLLEGE (Autonomous)
VISHAKAPATNAM – 531162
RAGHU ENGINEERING COLLEGE
(Autonomous)
VISHAKAPATNAM – 531162
CERTIFICATE
This is to certify that the project report entitled RAINWATER
HARVESTING submitted by 19981A0105, 19981A0110,20985A0101,
20985A0110, 20985A0113 of B.Tech 3rd year 2nd semester in WATER
RESOURCE ENGINEERING in partial fulfillment for the award of the
degree of B. Tech in CIVIL ENGINEERING is a bona fide record of project
work. The contents of this report, in full in parts, have not been submitted
to any other Institution or University for the award of any degree or
diploma.
Signature of Faculity
__________________________
DECLARATION
I declare that this project report titled RAINWATER
HARVESTING submitted in partial fulfillment of the degree of B.
Tech in CIVIL ENGINEERING is a record of original work
carried out by me under the supervision of Asst.prof
M.Krishna sumanth and has not formed the basis for the
award of any other degree or diploma, in this or any other
Institution or University. In keeping with the ethical practice in
reporting scientific information, due acknowledgements have
been made wherever the findings of others have been cited.
19981A0105
19981A0110
20985A0101
20985A0110
20985A0113
ACKNOWLEDGEMENT
First of all, I would like to say thank you, for giving me the
strength to do this project work. Not forgotten my parents for
providing everything, to buy anything that are related to this
project work and their advice, support which are the most needed
for this project. Internet, books, computers and all that. They also
supported me and encouraged me to complete this task so that I
will not procrastinate in doing it. Then I would like to thank my
teacher, M. KRISHNA SUMANTH sir for guiding me and my
team members throughout this project. They were helpful that
when we combined and discussed together, we had this task done.
Although, this report has been prepared with utmost care and deep
routed interest. Even then I, my team members accept respondent
and finalizing this project within the limited time frame.
CONTENTS











Abstract
Introduction
What is Rainwater Harvesting?
Need for rainwater harvesting
Rainwater Harvesting potential
Components of rooftop rainwater harvesting
Types of filters
Advantages of implementing rooftop rainwater harvesting
factors affecting the amount of rainwater harvested?
Conclusion
References
ABSTRACT
Rainwater Harvesting is the accumulating and storing, of
rainwater for reuse, before it reaches the aquifer . It has been used
to provide drinking water , water for livestock , water for
irrigation , as well as other typical uses given to water. Rainwater
collected from the roofs of houses, tents and local institutions, can
make an important contribution to the availability of drinking
water.
Water collected from the ground, sometimes from areas which are
especially prepared for this purpose, is called Stormwater
harvesting . In some cases, rainwater may be the only available,
or economical, water source. Rainwater harvesting systems can
be simple to construct from inexpensive local materials, and are
potentially successful in most habitable locations.
Roof rainwater can be of good quality and may not require
treatment before consumption. Although some rooftop materials
may produce rainwater that is harmful to human health, it can be
useful in flushing toilets, washing clothes, watering the garden
and washing cars; these uses alone halve the amount of water used
by a typical home. Household rainfall catchment systems are
appropriate in areas with an average rainfall greater than 200 mm
(7.9 in) per year, and no other accessible water sources (Skinner
and Cotton, 1992). Overflow from rainwater harvesting tank
systems can be used to refill aquifers in a process called
groundwater recharge , though this is a related process, it must
not be confused with Rainwater harvesting.
INTRODUCTION
Water is one of the most commonly used substances on our
earth. We need water for all our activities in day-to-day life.
Water supply in urban area is always shortage against the total
demand. Surface water inadequate to meet our demand and we
have to depend on ground water. Due to rapid urbanization,
infiltration of rainwater into the subsoil has decreased drastically
and recharging of ground water has diminished. This scenario
requires an alternative source to bridge the gap between demand
and supply. Rainwater, which is the purest form of water, would
be an immediate source to augment the existing water supply by
"catching water wherever it falls".
Rainwater Harvesting is the process of collecting and storing
rainwater in a scientific and controlled manner for future use.
Rainwater Harvesting in urban areas include roof top rainwater
harvesting, rainwater harvesting in paved and un-paved areas
(open fields, parks, pavement landscapes etc.). Rainwater
Harvesting in large areas with open ponds, lakes,
WHAT IS RAINWATER HARVESTING?
Rainwater Harvesting, also referred to as RWH, is a simple
method of collecting rainwater and deploying the same for
further usage. This is an increasingly important water
conservation method in apartments and gated complexes. It is
popular because it can result in significant savings and is easy to
implement.
NEED FOR RAINWATER HARVESTING
Water harvesting is the activity of direct collection of rainwater,
which can be stored for direct use or can be recharged in to the
ground water.
1. As water is becoming scarce, it is the need of the day to
attain self-sufficiency to fulfill the water needs.
2. As urban water supply system is under tremendous pressure
for supplying water to ever increasing population.
3. Groundwater is getting depleted and polluted.
4. Soil erosion resulting from the unchecked runoff.
5. Health hazards due to consumption of polluted water.
RAINWATER HARVESTING POTENTIAL
Rainwater Harvesting Potential in India. The total amount of
water that is received in the form of rainfall over an area is called
the rainwater endowment of that area. Out of this, the amount
that can be effectively harvested is called the water harvesting
potential.
Rainwater harvesting potential in urban areas is unlimited.
Consider the availability residential site of 40X60, with an area
of 2400sq.ft. /223 sq.mts., Around 2,23,000ltrs of rainwater can
be harvested in a location where the rainfall is around 1000mm or
39.4 inches (Bangalore receives around 1000mm of rainfall
annually). The amount of rainwater that can be harvested from the
available rainwater in the plot depends on potential rainfall,
catchment area available, collection methods and its efficiency
etc
COMPONENTS OF ROOFTOP RAINWATER
HARVESTING
The process involves transporting rainwater through pipes and
drain filtration and storage for reuse/recharge. Here are some
common components involved in these stages:
1. Catchments: Surface which directly receives the rainfall and
provides water to the system. It can be a paved area such as a
building terrace or courtyard, or an unpaved area such as a lawn
or an open ground. A roof made of reinforced cement concrete
(RCC), galvanised iron or corrugated sheets can also be used.
2. Channels: Water is collected around the edge of a sloping
roof in channels and is carried to a storage tank. The size of the
channel depends on the flow during heavy rain. It is advisable to
make them 10 to 15% larger. They can either be made from
plain galvanised iron (GI) sheet, polyvinyl chloride (PVC) or
even bamboo trunks.in the case of sloping roofs.our catchment
is rcc slab.
3. Conduits: Pipelines or drains that transport rainwater from
the catchment area to the harvesting system. Conduits can be of
PVC or galvanised iron.
4. First-Flushing: A valve that ensures that runoff from the first
spell of rain 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.
5. Filter: Removes suspended pollutants from rainwater
collected over the roof. A filter unit is a chamber filled with
filtering media such as fibre, coarse sand and gravel layers to
remove debris and dirt from water before it enters the storage
tank or recharge structure.
Types of Filters:
Charcoal water filter: A simple charcoal filter can be made in
a drum or an earthen pot. The filter is made of gravel, sand and
charcoal, all of which are easily available.
Sand filter: 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.
Rainwater Purification Centre (RainPC): A system designed for
the conversion of rainwater to drinking water. Coming in a small
compact 26 kg unit, the RainPC offers an affordable solution.
6. Storage Facility: There are multiple options available based
on the shape, size and material of construction.
Shape: Cylindrical, Rectangular and Square
Material: Reinforced cement concrete (RCC), ferrocement,
masonry, plastic (polyethylene) or metal (galvanised iron)
sheets.
Position of the tank: Depending on space availability, these
tanks could be constructed above ground, partly underground or
fully underground. Some maintenance measures like cleaning
and disinfection are required to ensure the quality of water
stored in the container.
7. Recharge Structures: Rainwater may be charged into the
groundwater aquifers, an underground layer of water-bearing
permeable rock, rock fractures or unconsolidated materials such
as gravel, sand, or silt, through any suitable structures like
dugwells, borewells, recharge trenches and recharge pits.
Recharge trenches and permeable pavements: These recharge
structures promote the percolation of water through soil strata at
shallower depth.
Recharge wells: These structures conduct water to greater
depths from where it joins the groundwater.
Recharge pits: The excavated pit, 1.5m to 3m wide and 2m to
3m deep, is lined with a brick/stone wall with openings (weepholes) at regular intervals. The top area of the pit can be covered
with a perforated cover. Design procedure is the same as that of
a settlement tank.
ADVANTAGES OF IMPLEMENTING ROOFTOP
RAINWATER HARVESTING:
1. To meet the ever increasing demand for water. Water
harvesting to recharge the groundwater enhances the availability
of groundwater at specific place and time and thus assures a
continuous and reliable access to groundwater.
2. To reduce the runoff which chokes storm drains and to avoid
flooding of roads.
3. To reduce groundwater pollution and to improve the quality of
groundwater through dilution when recharged to groundwater
thereby providing high quality water, soft and low in minerals.
4. Provides self-sufficiency to your water supply and to
supplement domestic water requirement during summer and
drought conditions.
5. It reduces the rate of power consumption for pumping of
groundwater. For every 1 m rise in water level, there is a saving
of 0.4 KWH of electricity.
6. Reduces soil erosion in urban areas
7. The rooftop rainwater harvesting is less expensive, easy to
construct, operate and maintain.
8. In saline or coastal areas, rainwater provides good quality water
and when recharged to ground water, it reduces salinity and helps
in maintaining balance between the fresh-saline water interfaces.
9.In Islands, due to limited extent of fresh water aquifers,
rainwater harvesting is the most preferred source of water for
domestic use.
10. In desert, where rainfall is low, rainwater harvesting has been
providing relief to people.
FACTORS AFFECTING THE AMOUNT OF
RAINWATER HARVESTED?
The factors affecting the amount of rainwater harvested are:



Catchment features
Quantum of runoff
The capacity of storage tanks
CONCLUSION
Rainwater harvesting is an eco-friendly technique to save water.
It also increases level of ground water. Effective use of
This method helps us to Save our earth. The harvested rainwater
can be used for non-potable purposes after employing filtration
from the designed composite rainwater harvesting unit. When
the quality aspects of main source of drinking water is looked
into, rainwater harvesting is an economical option to overcome
dependency on water supply. Also the rainwater quality
assessment indicates it’s relatively pollution free, indicating
considerably economical treatment.
REFERENCES
 https://readingjunction.com/rainwater-harvesting-methods/
 https://gupshups.org/rainwater-harvesting-essay/
 https://pages.uoregon.edu/hof/S01havestingrain/conclusion.
html
 http://164.100.47.193/Refinput/New_Reference_Notes/Eng
lish/Rainwater%20Harvesting.pdf
 https://www.thedotenvironment.com/DOCS/water%20harv
%20refs.pdf
 https://en.wikipedia.org/wiki/Rainwater_harvesting