The document discusses two methods of rainwater harvesting: rooftop rainwater harvesting used in India and runoff collection from roads in Brazil. Rooftop rainwater harvesting involves collecting rainwater from rooftop catchments and storing it in cisterns or tanks, while runoff collection uses underground pipes to collect rainwater from road gutters and store it in subsurface dams. Both methods provide a source of water for drinking and other uses and have low maintenance costs, though runoff collection carries risks of water contamination from roads.

1. INNOVATIONS THAT HELP TO
PRESERVE WATER
BY: ABHAYDEEP, RANVIR, JASKARAN,
JASHANPREET AND BHAVJEET

2. RAINWATER HARVESTING
USING ROOFTOP CATCHMENTS
IN INDIA

3. INTRODUCTION
 Rainwater harvesting is the accumulation and
deposition of rainwater for reuse before it reaches
the aquifer. Uses include watering the garden,
water for livestock, water for irrigation, and indoor
heating for houses etc. In many places the water
collected is just redirected to a deep pit with
percolation. The harvested water can be used
as drinking water as well as for storage and other
purposes.

4. EXTENT OF USAGE AND COST
 Rainwater harvesting is used greatly in Latin
America and the Caribbean, mainly for domestic
water supply and, in some cases, for agriculture.
It is also practiced in India in the wet and dry
regions. It is practiced in Rajasthan, Tamil Nadu
and Pune.
 Construction costs for underground cisterns can
vary tremendously, based on the size and the
amount of excavation required. In Saint Lucia, the
average cost of a 1, 5001 litre plastic tank is
$125. In India the cost is from Rs. 2,000 to Rs.
30,000 for buildings of 300 sq. m.

5. ADVANTAGES
 Rainwater harvesting provides a source of water
at the point where it is needed.
 It provides an essential reserve in times of
emergency and breakdown of public water
supply systems, particularly during natural
disasters.
 The construction of a rooftop rainwater
catchment system is simple, and local people can
easily be trained to build one, minimizing its cost.
 The technology is adjustable. The systems can
be built to meet almost any needs. Poor
households can start with a single small tank and
add more when they can afford them.

6. DISADVANTAGES
 The achievement of rainfall harvesting depends
upon the frequency and amount of rainfall
therefore, it is not a dependable water source in
times of dry weather.
 Low storage capacities will limit rainwater
harvesting so that the system may not be able to
provide water in a low rainfall period.
 Leakage from cisterns can cause the
deterioration of load bearing slopes.
 Storage tanks can be unsafe for small children if
proper access protection is not provided.

7. GLOSSARY
 CISTERNS= Storage tanks or reservoirs used for
storing water.
 FREQUENCY= Rate of occurrence.
 CATCHMENT= (here) A reservoir or basin used
for catching and storing rainwater.
 ACCUMULATION= The growth by continous
addition of rainwater in the storage tank.
 PERCOLATION= The slow movement of water
through pores in the soil.

8. RUNOFF COLLECTION FROM
PAVED AND UNPAVED ROADS
IN BRAZIL

9. INTRODUCTION
 Runoff collection is the collection of rainwater
using underground pipes in the gutters which
then transfer the water to a storage tank. In
countries like Brazil and Argentina, with semi-arid
climates in which the amount and frequency of
precipitation are small and variable, it is important
to capture and store as much rainwater runoff as
possible for later use. In Brazil, runoff from paved
and unpaved roads is captured by street gutters
and stored in subsurface dams which are
carefully distributed along the roadsides.

10. EXTENT OF USAGE AND COST
 This method of runoff capture has been used in
semi-arid regions of Brazil, Argentina, and
Venezuela.
 In Argentina, a forestation project on both sides of
a 1 km stretch of paved road cost about $2000.
Costs will vary as a function of the length of
roadway treated and the characteristics of the
pavement. Provision of a distribution system, if
required, could increase the cost per kilometer
substantially.

11. ADVANTAGES
 Runoff collection and storage enhance the flora
and fauna of a region.
 Runoff collection can enable agriculture in arid
and semi-arid regions.
 The technology has a low operating cost. The
capital cost can be classified in the cost of
constructing the road.
 It is easy to operate and maintain.

12. DISADVANTAGES
 The systems may require proper irrigation during
dry periods.
 Animals must be kept away from the plantings to
avoid damage that can be inflicted on the system.
 It requires convenient soil conditions.
 Water collected from roadways may be
contaminated by litter and debris and in the
urbanized areas, the water can be contaminated
by chemical pollutants from vehicles.

13. GLOSSARY
 CONTAMINATE= To be made impure or infect a
substance with chemicals, etc.
 SEMI-ARID= To receive very little rainfall.
 ARID= To be completely dry or without water and
moisture.
 RUNOFF= Something that drains away or flows
off .

14. DIFFERENCES
RAINWATER
HARVESTING RUNOFF COLLECTION
 Water is collected
using a basin in the
roof which then
transfers the water to
the cistern or storage
tanks.
 This method is used
in India, Latin
America, the
Caribbean, Costa
Rica, Guatemala and
El Savador.
 Water is collected
using underground
pipes which collects
the water and then
transfers it to a cistern
or a storage tank.
 This method is used
in the arid and semi-arid
areas of
Argentina, Brazil and
Venezuela.

15. SIMILARITIES
 Both methods are ways to preserve water.
 The resulting water can be used for drinking
purposes.
 The water can be used for several non-drinking
purposes such as watering the garden, washing
cars, etc.
 Both methods involve the usage of storage tanks
or cisterns.
 The systems are easy to operate and maintain.

16. REFERENCES
 www.wikipedia.org
 www.rainwaterharvesting.org
 www.oas.org

17. THANK YOU FOR LISTENING