This document discusses rain water harvesting as an alternative source of water. It notes that rain water harvesting involves collecting and storing rainwater, and has traditionally been used to provide drinking water, water for livestock, and irrigation. It then describes different rain water harvesting techniques like roof top harvesting and surface runoff harvesting. For roof top harvesting, rainwater is collected from building roofs and stored in tanks or used to recharge groundwater. Surface runoff harvesting involves collecting rainwater flowing along the ground. The document outlines the key elements, advantages, and some disadvantages of rain water harvesting.

1. Rain Water Harvesting : An
alternate Source of Water
By : Pradeep Limani Mentor: Mr. Bhaven Tandel
(U09CE077) Assistant Professor
CED, SVNIT

2. Introduction
 The total amount of water on earth
remains constant. The rapid growth in
population together with the extension of
irrigated agriculture and industrial
development, are putting stress on the
natural ecosystems. In the face of
growing problems, society has begun to
realize that it can no longer subscribe to
a use and discard philosophy with any
natural resource. One such resource is
WATER. To deal with it, a technique
called RAIN WATER HARVESTING was
introduced where rain water is used to

3. What is Rainwater Harvesting
 Rainwater harvesting is the accumulating and
storing, of rainwater. It has been used to
provide drinking water, water for livestock, water for
irrigation or to refill aquifers in a process
called ground water recharge.
 The principle of collecting and using precipitation
from a catchments surface.
 Rain water harvesting means to make optimum use of
rain water at the place where it falls i.e. conserve it and
not allow draining away and causing floods elsewhere.

4. Need of Rainwater Harvesting
 Water is becoming scarce.
 Surface water is inadequate to meet
our demand.
 We have to depend on ground water.
 To reduce soil erosion.
 Groundwater is getting depleted and
polluted.
 Improves the ground water quality.
 Increasing population of India.
 Of the total water on earth, only 3%
constitutes freshwater. Rest is saline
water in the oceans.
 11% of the total fresh water on earth
is groundwater available upto a depth
of 800m which can be extracted for
use

5. Rainwater Harvesting Techniques
Roof top rainwater
harvesting.
Surface runoff harvesting .

6. Roof Top Rain Water Harvesting
 In rooftop harvesting, the roof becomes the
catchments, 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. This method is less expensive and very
effective and if implemented properly helps in
augmenting the ground water level of the area.

7. How to Harvest Rainwater
 Collect water from the rooftop.
 Draw it down from pipes.
 Filter the water.
 Store in a sump or tank for later use.
 Charge the groundwater through a soak pit.
 Lead the water into a well to increase ground water content.

8. Elements of Rooftop Rainwater
Harvesting
 CATCHMENT
 COUNDITS
 FILTERS
 STORAGE
FACILITY

9. SURFACE RUNOFF
HARVESTING
 Harvesting of surface
runoff and storage of
the same into
reservoirs such as
water pans makes it
available for use when
required.
 In this method of
collecting rainwater for
irrigation, water flowing
along the ground
during the rains will be
collected to a tank

10. TRADITIONAL RWH
STRUCTURE
BAWODI:
 Traditional step
wells are called
vavadi in Gujarat, or
baoris or bavadis in
Rajasthan and
northern India.
 They were secular
structures from
which everyone
could draw water.
 Most of them are
defunct today.

11. Kunds or Kundis
 Covered underground
tank, developed primarily for
tackling drinking water
problems.
 Usually constructed with local
materials or cement, kunds were
more prevalent in regions where
groundwater is saline.
 Before the onset of rains every
year, meticulous care was taken
to clean up the catchment of the
kunds.
 The proximity of a kund to the
house or village saved time and
effort in searching for drinking
water.

12. Ooranis
 Designed to harvest
and store rainwater
to meet the drinking
needs of a
community.
 Created by
excavating the soil
which is then used
to form bunds
around the area.
 More than 39000
ooranis in
Tamilnadu state
alone

13. Paar System
 The rainwater flows
from the agar
(catchment area) and
in the process
percolates into the
sandy soil.
 Kuis or beris are dug
5 to 12 m deep to
access the water.
 Rainwater harvested
through the paar
technique is known
as patali paani.

14. Advantages of RWH
 RWH is the ideal solution for
all water requirements.
 Increase in ground water level.
 Reduces flooding of roads .
 Reduced soil erosion.
 Improves the ground water
quality.
 Low cost and easy to maintain.
 Reduces water and electricity
bills

15. Disadvantages of RWH
 Seasonal nature and uncertainty of rainwater supply
depending on the region in the world.
 Capital costs .
 Regular maintenance and cleaning is essential for
successful operation.

16. Summary
 On of the best way to solve the world burning
facing issue: Water Scarcity.
 Helps in Raising Ground water level.
 Saving of energy per lifting of well and saving of
Water bills.
 Harvested water can be used for Daily household
needs.
 It is economical.
 Its not a permanent solution as water is not
available throughout the year but it can be utilized
to its maximum extent.
 Water is an important resource we should be very
careful while dealing with it.

17. Rain Water Harvesting
Noble Goal

18. THANKYOU