Water harvesting

1. WATER HARVESTING:
COMPONENTS AND
CHARACTERISTICS

2. BENJAMIN FRANKLIN
“When the well is dry we know the
worth of Water.”

3. ● Water harvesting refers to the “collection of runoff for its
productive use”. The harvested water can then be used for
orchards/gardens, raising livestock, irrigation, domestic use
with proper treatment etc.
● The harvested water can also be used as drinking water,
longer-term storage, and for other purposes such
as groundwater recharge.
●Water harvesting is an old practice that is being adopted by
many countries as well as individuals to counter the problem
of water scarcity.
WATER HARVESTING

4. PROBLEM
MAJOR PROBLEM AND ITS IMPACTS LEADING TO WATER SHORTAGE
IMPACT
Increase in population rate is consequently
amplifying the quantitative demand of fresh
water. Moreover, rapid industrialization is
worsening the quality of fresh water, limiting
its quantitative availability.
Rapid urbanization coupled with
industrialization contribute in the
deterioration of fresh water resources. On
the other hand, population in expanding at an
alarming rate.

5. • In the recent years, due to change in the lifestyle of people, climate change and global
warming have begun to clout the environment at an alarming rate. Duration of various
seasons, including rainfall season have shortened at various parts of the world.
• Due to this, groundwater recharge has reduced significantly and people re not getting
enough water to meet their domestic needs. Crop cultivation and other economic activities
are also getting impacted by it.
• Water reservoirs including wells have dried up and people are finding it difficult to obtain
freshwater for their utilization.
• In this situation, water harvesting plays major role in diluting this crisis of water and
rejuvenate groundwater structures
IMPENDING WATER CRISIS

6. Various studies have pointed out how global warming is reducing
the monsoon season in India. It is a red alert for us to know about
the water crisis that may accompany it.

7.  Various methods of water harvesting are being used since the long time.
 According to the reports, the most ancient system comes from Middle east where agriculture was
based on diversion of “wadi” flow onto agricultural fields, was a kind of water harvesting and
recycling of harvested water for irrigation.
 Negev desert (Israel) reports the water harvesting systems have been reported to get use about 4000
years back or more, where water harvesting was done by clearing the hillsides from vegetation to
increase the runoff, and directing the runoff to the fields on the plains.
 Floodwater farming has been reported in practice in the desert areas of Arizona and north-west New
Mexico from at least 1000 years back
 “Khadin” system, in India has been in use for a long time in which floodwater is impounded behind
earthen bunds; and crops are planted in the field based on the residual moisture contents, which was
due to infiltration from impounded water
HISTORICAL DEVELOPMENT OF WATER HARVESTING

9. PRINCIPLES
SEVEN BASIC PRINCIPLES OF WATER HARVESTING

10. INTRODUCTION
The basic principle of water harvesting is to capture
precipitation falling in one area and transfer it to another,
thereby
increasing the amount of water available for storage.

11. 1
Observe where the water flows, where it
collects, where it drains away, where it
drains from. This will give us an idea about
resources and challenges. What will work ,
what will not ….

12. 2
It is easier to harvest water high in watershed than in
low in the watershed because the volume and
velocity of flow is less and more manageable at the
top. Also we can use free power of gravity to
distribute the harvested water to areas down-slope.

13. Small simple systems of appropriate scale are easier
to create and maintain than complex, extensive
systems. Large numbers of small earthwork
structures distributed throughout a watershed will be
far more effective at hydrating the land than a small
number of large-scale earthwork structures in just a
few areas of the watershed.
3

14. MORE EARTHWORK -
MORE
REHYDRATION OF
SOIL - MORE WATER
AVAILABLE!
earthwork

15. Zigzag flow-path of water calms the flow of water
thus reducing destructive erosion and increase the
time and distance the water flows. This will increase
infiltration into the soil from the source (high point)
to the sink(low point) .
4

16. Slow -SPREAD- INFILTRATE

17. Always be prepared for an overflow. In a situation
where overflow happens water should be directed to
fill a nearby , vegetated earthwork, then overflow to
the next earthwork , as it passively irrigates
vegetation there. Zig-zagging path is ideal.
5

18. Maximize planting of climate appropriate vegetative
ground cover and spread organic mulch over the
surface of the surface to great ‘living sponge’ that
uses harvest water to grow more resources. As roots
expand and soil life increases the soil’s ability to
infiltrate and hold water steadily increases.
6

19. ‘LIVING SPONGE’ -ORGANIC MULCH

20. How is land responding to the system, how are
the strategies performing? Is it efficient?
Evaluation should be done through out the life
span of the system.
7

21. INTRODUCTION
The applicability and impact of water harvesting
technologies depend on local conditions. There are
specific “pros” and “cons” associated with water
harvesting .

22. BENEFITS
Providing an
alternative to full
irrigation
Increasing
resilience of
systems
Increasing
water
availability
Buffering rainfall
variability Overcoming
dry spells
Offering flexibility
and adaptability to
suit circumstances
Reducing
production risks,
thus reducing
vulnerability
Helping to cope
with extreme
events
Securing water
and productivity
in dryland areas

23. Reducing
migration to the
cities
Offering the
possibility of
growing higher-
value crops
Utilizing and
improving
local skills
Improving access to
clean and safe
domestic water
Alleviating poverty:
when adopted at
scale
Reducing
women’s work
load
Increasing food
production and
security
Improving water
availability for
livestock
BENEFITS Indirect
Benefit

24. BENEFITS
Production and income:-
Floodwater harvesting shows a clear increase in yield and income.
Floodwater is mostly related to annual crop production on larger
areas. Macro- and microcatchment also include perennial crops and
trees for envrionmental protection which take longer to show
production benefits and higher income. Some of the
macrocatchments mainly provide water for dometic use
Gragh clearly shows increased production and income as a result of
floodwater harvesting (as it gives results fatser).

25. ● Water use efficiency: As expected all Water
Harvesting groups indicate improved water use
efficiency, mostly high to medium. This relates to
reduced evapotranspiration loss and improved soil
water availability.
● Thus increased water use efficiency can be
considered a benefit of water harvetsing.
BENEFITS

26. ● Erosion control: Apart from RooftopWater Harvesting all
other groups show medium to high erosion control. Best
rated are FloodWH and MircoWH, whereas in the group of
MacroWH erosion control is still a challenge with respect
to surface dams due to management constraints of the
catchment area.
BENEFITS

27. Water made available to arid
regions through water
harvesting

28.  Water harvesting technologies also come with uncertainties and risks; the first is their dependence on
variable rainfall. In developing regions, the prevailing climatic conditions include strong seasonality
and erratic rainfall.
 While water harvesting can help manage these, where they are extreme they can make specific
technologies less effective or even lead to increased soil erosion if structures breach.
 Water harvesting structures may take land out of productive use.
 Water harvesting can lead to loss of habitat of flora and fauna due to clearance of slopes, or where
harvested water fills up depressions.
CONSTRAINTS

29. CONSTRAINTS
Dependent on the
amount, seasonal
distribution and -
variability of rainfallall
Difficult to ensure
sufficient quantity of
water needed
Supply can be limited
by storage capacity,
design and costs
Structures /
microcatchments may
take up productive land
5)Ponded water can be
breeding ground for
mosquitos or source of
waterbourne diseases
May involve high initial
investments and/or
labour requirements for
maintenance
Long-term institutional
support may be
necessary
May deprive
downstream -
ecosystems of water
(esp. where
17)floodwater is
diverted)
Shared catchments and
infrastructure may
create rights issues
Acceptance of new
systems and associated
rules and regulation
may be a problem
Jointly used structures
can lead to
maintenance
disagreements
Acceptance of new
systems and associated
rules and regulation
may be a problem

30. Water harvesting Techniques
Includes runoff harvesting, flood water harvesting and
groundwater harvesting techniques

31. Short Term
Runoff Harvesting Techniques
Long Term
Dugout Ponds, Silt Detention Dam, and
Percolation Dam
Includes Contour Bunds, Semicircular Hoops,
Trapezoidal Bunds, Graded Bunds, Rock
Catchment, Ground Catchment

32. Short Term Runoff Harvesting Techniques
Contour Bunds: This method involves the construction of bunds
on the contour of the catchment area (Fig. 28.1). These bunds hold
the flowing surface runoff in the area located between two
adjacent bunds. Height; 0.30 to 1.0 metres and Length; 10 to
some 100 metres
Semicircular Hoop:
This type of structure consists of an earthen embankment
constructed in the shape of a semicircle. The water contributed
from the area is collected within the hoop to a maximum depth
equal to the height of the embankment.
Excess water is discharged from the point around the tips to
the next lower hoop.

33. Trapezoidal Bunds: Such bunds also consist of an earthen
embankment, constructed in the shape of trapezoids. The
tips of the bund wings are placed on the contour. The
runoff water yielded from the watershed is collected into
the covered area. The excess water overflows around the
tips. In this system of water harvesting the rows of bunds
are also arranged in staggered form to intercept the
overflow of water from the adjacent upstream areas. This
technique of water harvesting is widely used for irrigating
crops, grasses, shrubs, trees etc.
Graded Bunds: Graded bunds consist of earthen or
stone embankments and are constructed on a land
with a slope range of 0.5 to 2%. The design and
construction of graded bunds are different from the
contour bunds. They are used as an option where
rainfall intensity and soils are such that the runoff
water discharged from the field can be easily
intercepted. The excess intercepted or harvested
water is diverted to the next field though a channel
ranges.

34. Rock Catchment: The rock catchments are the exposed rock surfaces, used for collecting the runoff water in a
part as depressed area. The water harvesting under this method can be explained as: when rainfall occurs on the
exposed rock surface, runoff takes place very rapidly because there is very little loss. The runoff so formed is
drained towards the lowest point called storage tank and the harvested water is stored there. The area of rock
catchment may vary from a 100 m2 to few 1000 m2; accordingly the dimensions of the storage tank should also
be designed. The water collected in the tank can be used for domestic use or irrigation purposes.

35. Ground Catchment: In this method, a large area of ground is used as catchment for runoff yield. The runoff is
diverted into a storage tank where it is stored. The ground is cleared from vegetation and compacted very well. The
channels are as well compacted to reduce the seepage or percolation loss and sometimes they are also covered
with gravel. Ground catchments are also called roaded catchments. This process is also called runoff inducement.
Ground catchments have also been traditionally used since last 4000 years in the Negev (a desert in southern
Israel) where annul crops and some drought tolerant species like pistachio dependent on such harvested water are
grown.

36. Long Term Runoff Harvesting Techniques
Dugout Ponds: The dugout ponds are constructed by excavating the soil from
the ground surface. These ponds may be fed by ground water or surface
runoff or by both. Construction of these ponds is limited to those areas which
have land slope less than 4% and where water table lies within 1.5-2 meters
depth from the ground surface (Fig. 28.4). Dugout ponds involve more
construction cost, therefore these are generally recommended when
embankment type ponds are not economically feasible. The dugout ponds can
also be recommended where maximum utilization of the harvested runoff
water is possible for increasing the production of some important crops. This
type of ponds require brick lining with cement plastering to ensure maximum
storage by reducing the seepage loss.

37. Silt Detention Dam: The basic purpose of silt detention dam is
to detain the silt load coming along with the runoff water from
the catchment area and simultaneously to harvest water. The
silt laden water is stored in the depressed part of the
catchment where the silt deposition takes place and
comparatively silt free water is diverted for use. Such dams
are located at the lower reaches of the catchment where
water enters the valley and finally released into the streams.
In this type of dam, provision of outlet is made for taking out
the water for irrigation purposes. For better result a series of
such dams can be constructed along the slope of the
catchment
Percolation Dam: These dams are generally
constructed at the valley head, without the
provision of checking the percolation loss. The
growing crops on downstream side of the
dam, receive the percolated water for
their growth.

38. Flood Water Harvesting
Permeable Rock Dams (for Crops)
These are long low rock dams across valleys
slowing and spreading floodwater as well as
healing gullies. These are suitable for a
situation where gently sloping valleys are likely
to transform into gullies and better water
spreading is required.

39. Water Spreading Bunds (for Crops and
Rangeland): In this method, runoff water is diverted
to the area covered by graded bund by constructing
diversion structures such as diversion drains..
Floodwater farming systems: (a) spreading within channel bed; (b)
diversion system
Flood Control Reservoir: The reservoirs
constructed at suitable sites for controlling
the flood are known as flood control
reservoirs. They are well equipped with self-
operating mechanical outlets for letting out
the harvested water into the stream or canal
below the reservoir as per requirement.

40. GroundWater Harvesting
Qanat System: A qanat consists of a long tunnel or conduit leading from a well dug at a reliable source of groundwater (the
mother well). Often, the mother well is dug at the base of a hill or in the foothills of a mountain range. The tunnel leading from the
mother well slopes gradually downward to communities in the valley below. Access shafts are dug intermittently along the
horizontal conduit to allow for construction and maintenance of the qanat. The Qanat system was used widely across Persia and
the Middle East for many reasons. First, the system requires no energy, relies on the force of gravity alone. Second, the system can
carry water across long distances through subterranean chambers avoiding leakage, evaporation, or pollution. And lastly, the
discharge is fixed by nature, producing only the amount of water that is distributed naturally from a spring or mountain, ensuring
that the water table is not depleted. More importantly, it allows access to a reliable and plentiful source of water to those living in
otherwise marginal landscapes

41. Components of water harvesting
The rain water harvesting system consists of following basic components –
● (a) Catchment area
● (b) Coarse mesh / leaf screen
● (c) Gutter
● (d) Down spout or conduit
● (e) First flushing device
● (f) Filter
● (g) Storage tank
● (h) Recharge structure

42. ● The surface that receives the rainfall directly and transfers water
to the system is called catchment area. It can be a paved area
such as a building’s terrace or patio, or an unpaved area such as a
lawn or open field. Often usable for water harvesting is a roof
made of reinforced cement concrete ( RCC), galvanized iron or
corrugated sheets.
1.catchment area 2.COARSE MESH/LEAF SCREEN
• Coarse Mesh prevents the passage of debris, provided in the roof.
• For slope in roofs where gutters are provided to collect and divert
the rain water to downspout or conduits, the gutters have a
continuous leaf screen, made of 1⁄4 inch wire mesh in a metal frame,
installed along their entire length, and a screen or wire basket at the
head of the downspout.

43. ● Gutter is required to be used for collecting water from
sloping roof and to divert it to downspout. These are the
channels all around the edge of a sloping roof to collect and
transport rain water to the storage tank.
● Gutters can be of semi-circular, rectangular or trapezoidal
shape. Gutters must be properly sized, sloped and installed
in order to maximize the quantity of harvested rain.
3. gutter
• Gutter can be made using any of the following materials:
(a) Galvanized iron sheet
(b) Aluminum sheet
(c) Semi-circular gutters of PVC material which can be readily prepared by cutting these
pipes into two equal semi-circular channels
(d) Bamboo or betel trunks cut vertically in half (for low cost housing projects )
• The size of the gutter should be according to the flow during the highest intensity rain.

44. The rain water collected on the roof top is transported down
to storage facility through down spouts / conduits.
Conduits can be of any material like PVC, GI or cast iron.
The conduits should be free of lead and any other treatment
which could contaminate the water.
4. DOWN SPOUT OR CONDUIT 5. FIRST FLUSHING DEVICE
A first flush device is 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.

45. 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.
6. FILTER
TYPES OF
FILTER
• SAND FILTER
CHARCOL WATER FILTER
DEWAS FILTER
VARUN
HORIZONTAL ROUGHENING FILTER AND SLOW
SAND FILTER
RAIN WATER PURIFICATION CENTRER
Apart from these , there are many more filters
such as - Cloth Filter , Desilting Chambers,
Weave Wire Filter, Popup Filter etc.

46. SAND FILTER
• Sand as filter media
• Easy and inexpensive to construct.
• Effectively remove turbidity
(suspended particles like silt and
clay), color and microorganisms
CHARCOL 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.
DEWAS WATER FILTER
• 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 a filter system called the Dewas fillter, designed
by Mohan Rao, district collecter of Dewas and engineers
of the rural engineering services.
• The water thus filtered is put into the service tubewell.

47. • The filter removes suspended
solids from the harvested
rainwater.
• Developed by S Vishwanath, a
Bangalore based water
harvesting expert.
• According to him, from a
decently clean roof 'VARUN' can
handle a 50 mm per hour
intensity rainfall from a 50 sq
m roof area.
• One of the most effective filter For
purification of water being used in
coastal areas of Orissa.
• The HRF acts as a physical filter and is
applied to retain solid matter, while slow
sand filter (SSF) is primarily a biological
filter, used to kill microbes in the water.
• The water is first passed through the
HRF and then through SSF.
• Developed by three Netherlands based
companies for conversion of rain water to
drinking water and is popularly known as
Rain PC.
• Rain PC is made of ultra violet resistant
poly ethylene housing and cover, stainless
steel rods and bolts, a nickel-brass valve
and an adapter for maintaining constant
volume.
VARUN HORIZONTAL ROUGHENING FILTER
AND SLOW SAND FILTER
RAIN WATER
PURIFICATION CENTER

48. • There are different options available for the
construction of these tanks in terms of form,
height, construction material and tank
location and they are: –
• Shape: Cylindrical, Square and Rectangular.
• Material of construction: Reinforced
cement concrete, (RCC), ferrocement,
masonry, plastic (polyethylene) or metal
(galvanized iron) sheets are commonly used.
• Position of 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. STORAGE

49. 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 depths from where it joins the groundwater (e.g.
recharge wells).
Here are a few commonly used recharging methods:
8. Recharge structure
Recharging of dugwells and
abandoned tubewells
Settlement tanks
Recharging pits

50. Soakways/ Percolation Pits
Recharge Trenches Modified Injection wells
Rainwater collected on the building’s rooftop is redirected by drainpipes into a settlement or filtration tank, from which it flows deep into
the recharge (borewell or dugwell).
Settlement tanks are used to extract silt and other impurities that collect from rainwater.
A settlement tank is like an ordinary storage container that has supplies for inflow (to bring water from the catchment), outflow (to take
water to the recharge well) and flood.
A settlement tank may have an unpaved bottom surface that enables the percolation of standing water into the soil.

51. RAIN WATER
HARVESTING

52. What is Rain Water Harvesting?
Rainwater harvesting, in its broadest sense, is a technology used for collecting and storing rainwater for human use
from rooftops, land surfaces or rock catchments using simple techniques such as jars and pots as well as engineered
techniques.
It has been practiced for more than 4,000 years, owing to the temporal and spatial variability of rainfall. It is an
important water source in many areas with significant rainfall but lacking any kind of conventional, centralized
supply system.
Its practice effectively divides into
 Domestic RWH
 RWH for agriculture, erosion control, flood control and aquifer replenishment.
Rainwater harvesting can be done at individual household level and at community level in both urban as well as rural
areas. At household level, harvesting can be done through roof catchments, and at community level through ground
catchments

53. DIAGRAM:

54. Surface Runoff RWH
Major Techniques of Rain Water Harvesting
Ground water Recharge
In this method, rainwater flows away as surface
runoff and can be stored for future use. Surface
water can be stored by diverting the flow of
small creeks and streams into reservoirs on the
surface or underground. It can provide water
for farming, for cattle and also for general
domestic use. Surface runoff harvesting is
most suitable in urban areas.
Rooftop rainwater/storm runoff can be
harvested in
• Recharge Wellurban areas through:
• Recharge Pit
• Recharge Trench
• Tubewell
Groundwater recharge is a hydrologic process where
water moves downward from surface water to
groundwater. The surplus rainwater is used to
recharge groundwater aquifer through artificial
recharge techniques.
Rainwater in rural areas can be harvested through:
• Gully Plug
• Contour Bund
• Dugwell Recharge
• Percolation Tank
• Check Dam/Cement Plug/Nala Bund
• Recharge Shaft

55. Surface Runoff Rain Water Harvesting:
Ground Water Recharge:

56. Classification
The upcoming slides classifies Rain Water
Harvesting System according to various criterias:
 Catchment Areas
 Reliability

57. roof catchment systems
Types of rain Water Harvesting
The water is collected on the
roofs of the houses and then
dirested to dfferent areas
through pipes and drains
rock catchment systems
It is a rainwater catchment area
developed from a rock outcrop to
catch and concentrate runoff
into a storage structure for later
use
ground catchment
systems
The water is collectted in
underground Reservoirs
Rainwater harvesting can be categorised according to the type of catchment surface used, and by
implication the scale of activity
check and sand dams
The small dams retain excess
water flow during monsoon rains
in a small catchment area
behind the structure.

58. Occasional
Types of Rain Water Harvesting
water is stored for a few days only in
a small container. Suitable when there
is a uniform rainfall pattern with very
few days without rain and there is a
reliable alternative water source
nearby.
Intermittent
In situations with one long rainy
season when all water demands
are met by rainwater; however,
during the dry season, water is
collected from non-rainwater
sources.
Partial
Rainwater is used throughout the
year but the ‘harvest’ is not
sufficient for all domestic demands.
For instance, rainwater is used for
drinking and cooking while for other
domestic uses (e.g. bathing and
laundry) water from other sources
is used.
Rainwater systems can further be classified by their reliability, which give four types of user regimes:
FULL
For the whole year, all water for all
domestic purposes is rainwater. In such
cases, there is usually no alternative
water source other than rainwater

59. Transportation
Filter
First Flush
Catchments
Components of Rain Water Harvesting
First flush is a device used to flush off the water received in first shower. The
first shower of rains needs to be flushed-off to avoid contaminating
storable/rechargeable water by the probable contaminants of the atmosphere
and the catchment roof.
The surface that receives rainfall directly is the catchment of
rainwater harvesting system. It may be terrace, courtyard, or paved
or unpaved open ground.
Rainwater from rooftop should be carried through down
take water pipes or drains to storage/harvesting system.
Filters are used for treatment of water to effectively remove
turbidity, colour and microorganisms. It removes silt, dust,
leaves and other organic matter from entering the storage
tank.

60. PVC-Pipe Filter
Sponge Filter
Charcol Filter
Sand Gravel Filter
Types of Filters

61. Advantages of Rain Water Harvesting
 Rainwater harvesting systems can provide water at or near the point where water is needed or used.
The systems can be both owner and utility operated and managed.
 Rainwater is relatively clean and the quality is usually acceptable for many purposes with little or even
no treatment.
 The physical and chemical properties of rainwater are usually superior to sources of groundwater that
may have been subjected to contamination.
 Rainwater harvesting technologies are flexible and can be built to meet almost any requirements.
Construction, operation, and maintenance are not labour intensive.

62. Examples of Rain Water Harvesting
 A rainwater harvesting system for tubewell recharge is implemented in Pipriya Tehsil of Madhya
Pradesh. A tubewell recharge pit is dug by members of the community, with holes that allow water
without sediment to go down into the tubewell. Stones and rocks are filled in the recharge pit for
water filtration.
 One instance where a RWH system has been successfully implemented is Green Land Society 2 at
Vimannagar, Pune. Previously, the water table at Green Land Society 2 was at 250 feet depth but
after the implementation of RWH system, the water table has moved up to 40 feet. Earlier tankers
were necessary during the summer season but no water tanker has been summoned for the last 13
years due to the RWH system.

63. Rain Water Harvesting:

64. IMPORTANCE OF WATER HARVESTING

65. IMPORTANCE OF WATER HARVESTING
 Water is the most essential natural resource for life. It is
likely to become a critical scarce resource in many regions of
the world in the coming decades.
 In most urban areas, population is increasing rapidly and the
issue of supplying adequate water to meet societal needs and
to ensure equity in access to water is one of the most urgent
and significant challenges faced by decision-makers.
 Rainwater harvesting, in its broadest sense, is a technology
used for collecting and storing rainwater for human use from
rooftops, land surfaces or rock catchments using simple
techniques such as jars and pots as well as engineered
techniques.
 The application of appropriate rainwater harvesting
technology is important for the utilization of rainwater as a
water resource.

66. reduce peak runoff
SIGNIFICANT OBJECTIVES OF WATER HARVESTING
increase base flow
reduce the risk of
flood in down stream areas
extend the time response to
runoff generation
increase available water for
irrigation and other uses
recharge
groundwater
Water body and water harvesting system ( Dwarka sec 23, New Delhi )

67. SOLUTION TO WATER CRISIS
 Rainwater harvesting or the collection
of rainwater in a proper way, can be a
permanent solution to the problem of
water crisis in different parts of the
world.
 This simple method can put forward a
solution which will be workable in areas
where there is sufficient rain but the
groundwater supply is not sufficient on
the one hand and on the other surface
water resource is insufficient.

68. scarcity of water Self-Sufficiency
 In areas having sparse and irregular
rainfall, scarcity of water is a persistent
problem.
 It cannot be completely resolved but can
be mitigated through rain water
harvesting.
 Rainwater harvesting is an ideal solution
to water problems in regions which
receive inconsistent rainfall throughout
the year.
 Self-Sufficiency in Water Supply,
Without Being Dependent on Remote
Water Sources.
 Many cities around the world obtain
their water from great distances ‐
often over 100km away.
 But this practice of increasing
dependence on the upper streams of
the water resource supply area is not
sustainable

69. AGRICULTURAL need for water harvesting
 Although the earth is three-fourths water; very little of
it is suitable for human consumption or agriculture.
 Rainfall is unpredictable and there is a constant
shortage of water in countries which are agriculture
dependent or generally drought prone.
 The farmers are the most affected because they do not
get sufficient water for their fields.
 Rainwater harvesting therefore is an ideal solution for
farmers who depend on monsoon for consistent water
supply.

70. Accessibility of clean water
 Unavailability of clean water compels the
consumption of polluted water, giving rise
to water-borne diseases. and high rate of
infant mortality.
 In recent studies it has been observed that
in Lima (Peru) nearly 2 million people do not
have access to any water supply and those
who do have access get water supply which
has a high possibility of being contaminated.

71. WATER HARVESTING EXAMPLE FROM SURROUNDING
 The Gold Croft Co-Operative Society is under
construction in Sector-11, Dwarka.
 The total area of the society plot is 19,771
sq.m. out of which about 18735.14 sq.m. of
area is contributing runoff generation to be
utilized for recharge to ground water.
 The total area of the society plot is 19,771
sq.m. out of which about 18735.14 sq.m. of
area is contributing runoff generation to be
utilized for recharge to ground water.

72. Technology Development
and training
Networking
Implementation Policy
A Systematic Approach
What is Necessary for Promotion and Further Development of
Rainwater Utilization?
Encouraging technology and human resources
development to support rainwater
utilization is very important.
To promote rainwater harvesting and utilization as an
environmentally sound approach for sustainable
urban water management,
a network should be established involving government
administrators, citizens,
architects, plumbers and representatives of equipment
manufacturers.
Various implementation policies should be
established to make rainwater utilization and
other measures a
part of the social system.
Rainwater utilization, together with water conservation and
wastewater reclamation, should be incorporated into
municipal ordinances and regulations.

73. • KOTLA is an underdeveloped village situated at the foothills of Aravalis.
During rainy season, with no obstruction in way, the water used to flow
through the village streets bringing a large number of small rocks from
the hills. Because of high ground gradient this run off used to flow very
fast. The concentration time over the ground was very less resulting in
minimal percolation. At the same time the high velocity of flow caused
erosion to top fertile soil in agricultural fields.
• Moreover the freshwater was available only to the stretch of 200
meters under the hills while rest of the village used saline water. To
worsen the situation, due to lack of recharging, fresh water resources
were too depleting at an alarming rate due to overexploitation and
public water supply tube well started to yield saline water.
KOTLA VILLAGE PROFILE
KOTLA VILLAGE Case STUDY

74. CHECK DAMS
WATER HARVESTING MEASURES ADOPTED BY THE VILLAGERS
It’s the closest planet to the
Sun and the smallest in the
Solar System
RIDGE AND VALLEY METHOD
Venus has a beautiful name and is the
second planet from the Sun
TRANSFORMATION OF WELLS
Despite being red, Mars is actually
a cold place. It’s full of iron oxide
dust
Two check dams were
constructed that improved the
quality of water and amplified
ground water table. According to
reports, a farmer whose tube well
was more than 500 meters away
from the check dam, began
delivering sweet water which
used to be saline previously and
this could be possible because of
the rain water harvested by the
check dam.
It was mainly done to minimize
erosion and increase recharging
potential of storage basin. This
was carried out through a series
of check dams wherever
possible with the idea that
backwaters of a check dam
touch the preceding check dam
in the stream such that the
whole length of this stream
becomes storage and
percolation basin.
Dry and abandoned wells have
been transformed into water
harvesting structures by diverting
the flow of rainwater into them.
Also, as these wells were
connected with aquifers
harvesting significant amount of
rainwater, a filtration mechanism
was developed so that the wells
may rejuvenate with the rise in
water table.

75. The image shows one of the check dam
structure that was developed in Kotla
village to harvest rainwater

76. CONCLUSION
In densely populated country like India, the demand for water goes on increasing with increase in population , thus problems arise
such as water scarcity.
Rainwater naturally and freely available source can be properly utilized by means of water harvesting and recharging. Rainwater
Harvesting holds vast benefits. 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. Rainwater harvesting is simple & cost effective. If such simple
measures to “Catch water where it falls”, is taken by individuals, most of the water management problems can be solved.
Suggestions
• Reduce your needs.
• Reuse or recycle as much water as you can.
• Harvest & conserve water.
• Take Initiatives in conserving &preserving this life-giving resources for posterity.
• Let us not waste even a single drop of rainwater.
Our Mission Should Be:
• Conservation of water.
• Since we cannot produce energy we can save it by preventing wastage.
• In the same way we can not produce water but save it and protect our future.

77. BIBLIOGRAPHY
1. http://www.rainwaterharvesting.org/urban/components.htm
2. https://www.geographynotes.com/essay/water-harvesting/essay-on-water-harvesting-
geography/6300
3. https://www.indiawaterportal.org/articles/harvesting-water-harnessing-life-case-study-kotla-village-
mewat-rajasthan
4. The eight water-harvesting principles - Brad Lancaster
5. https://megphed.gov.in/rainwater/Chap5.pdf

78. CREDITS: This presentation template was created by Slidesgo, including icons by
Flaticon, and infographics & images by Freepik
GROUP MEMBERS-
KINZONG DOMA BHUTIA ( Water Harvesting Techniques)
KRIPA BARADWAJ (Rain Water Harvesting)
MANYA SRIVASTAVA (Introduction & case Study)
NIKITA DAHIYA (Importance)
NIKITA NIBHORIA (Components & conclusion)
NIVETHITA (Principles)
THANKYOU!