Rainwater harvesting is the accumulation and storage of rainwater runoff for reuse on-site rather than allowing it to flow off. It involves collecting rainwater from rooftops using simple techniques like jars and pots or more complex systems like underground check dams. The collected water can be used for recharging groundwater, gardening, drinking, and irrigation. There are two main methods of rainwater harvesting - surface runoff harvesting from urban areas and rooftop harvesting where the roof acts as a catchment to collect rainwater into a storage system through pipes. Proper filtration is important to remove contaminants before using the stored water.

1. RAIN WATER HARVESTING
PRESENTED BY:
RIJO VARGHESE

2. WHAT IS RAIN WATER HARVESTING?
 Rainwater harvesting is a technology used for collecting and
storing rainwater from rooftops, the land surface or rock
catchments using simple techniques such as jars and pots as
well as more complex techniquessuch as underground check
dams.
 Rainwater harvesting is the accumulation and
depositionof rainwater forreuseon-site, rather than
allowing it to runoff.

3. USES OF RAIN WATER
 Recharge under groundwater.
 Gardening.
 Drinking purpose.
 For irrigation purpose.

4.  Rainwater harvesting technologiesare simple to install and
operate.
 Local peoplecan beeasily trained to implementsuch
technologies, and construction materials are also readily
available.
 Running costs, also, are almostnegligible.
 Watercollected from roof catchments usually isof
acceptablequality fordomesticpurposes.
ADVANTAGES

5. How we can harvest rainwater?
Broadly there are two ways harvesting rainwater :-
• Surface runoff harvesting .
• Roof top rainwaterharvesting.

6. • Surface runoff harvesting:-
In urban area rainwater flows away as surface runoff. This
runoff could be caught and used for recharging aquifers by
adopting appropriate methods.
• Roof top rainwaterharvesting:-
It is asystem of catching rainwaterwhere it falls. In rooftop
harvesting, the roof becomes the catchments, and the
rainwater is collected from the roof of the house/building. This
method is less expensive and veryeffective.

7. COMPONENTS OF THE ROOF TOP RAINWATER HARVESTING SYSTEM.
• Catchment area
• Transportation
• Storage system
• Delivery system
• Filtration system

8.  The surface that receives rainfall directly is the
catchment of rainwater harvesting system. Itmay
be terrace, courtyard, or paved or unpaved open
ground.
CATCHMENTAREA

9.  Rainwater from rooftop should be carried down
through waterpipes ordrains to storage/harvesting
system. Water pipesshould be UV resistant (PVC
pipes) ofrequired capacity.
TRANSPORTATION

10. STORAGE SYSTEM
 All collected rain waterare store in tank or barrels used.

11.  It is a system used to deliver water for use. There are
different ways by which water from tank can betakenout
and delivered for many purpose .Water is delivered by
pipes .
DELIVERYSYSTEM

12.  Filters are used for treatment of water to effectively
remove turbidity, colour and microorganisms. After first
flushing ofrainfall, water should pass through filters.
There are different types of filters in practice, but basic
function is to purifywater.
FILTRATIONSYSTEM

13. WHY DO PEOPLE HARVEST RAIN WATER?
Rainswater isaprecious resourcedue to increases in demand from our ever
growing population. Changes in rainfall patterns in UK haveseen both
drought conditions and flooding.
• Rainwater harvesting can providearound 50 percent of a family’s water
needs.
• This notonlysaveswater, but saves moneyand reduces our impacton
theenvironment.
 Toinculcateacultureof waterconservation
 Toreduce soilerosion

14. EXAMPLES
 In the state of Tamil Nadu, rainwater harvesting was made
compulsory forevery building toavoid ground waterdepletion.
 In Rajasthan, rainwater harvesting hastraditionally been
practiced by the peopleof the Thar desert.
 At present, in Pune (in Maharashtra), rainwater harvesting is
compulsory forany new society to be registered.

15. THANK YOU