Rain Water Harvesting

1. RAIN WATER HARVESTING

2. INTRODUCTION
At the rate which population is increasing, it
is said that India will surely replace China
from its number 1 position of most densely
populated country of the world after 20-30.
These will lead to high rate of consumption
of most valuable natural resource “Water” is
resulting in augmentation of pressures on
the permitted freshwater resources. In order
to conserve and meet our daily demand of
water requirement, we need to think for
alternative cost effective and relatively
easier technological methods of conserving
water.

4. OBJECTIVES
i. To define water harvesting and its features.
ii. To study the advantages and
disadvantages of rainwater harvesting.
iii. To study the economic efficiency of
rainwater harvesting technology.
iv. To study the criteria for selection of
rainwater harvesting technologies.
v. To study how rainwater harvesting is
practiced in India.
Following are the main objectives of
preparing this
assignment:

6. RAINWATER HARVESTING SYSTEMS AND ITS FEATURE
Rainwater Harvesting is a simple technique of catching
and holding rainwater where its falls. Either, we can store
it in tanks or we can use it to recharge groundwater
depending upon the situation.
Features of Rainwater Harvesting are:
1. Reduces urban flooding.
2. Ease in constructing system in less time.
3. Economically cheaper in construction compared to
other sources, i.e. dams, diversion etc.
4. Rainwater harvesting is the ideal situation for those
areas where there is inadequate groundwater supply or
surface resources.
5. Recharging water into the aquifers which help in
improving the quality of existing groundwater through

8. BENEFITS OF RAINWATER HARVESTING:
Rainwater harvesting in urban and
rural offers several benefits including
provision of supplement water,
increasing soil moisture levels for
urban greenery, increasing the
groundwater. In homes and
buildings, collected rainwater can be
used for filtration and irrigation,
harvested rainwater can also be used
for showering, bathing or drinking.

10. ADVANTAGES:
• Rainwater is a relatively clean and free
source of water
• It is owner-operated and managed
• It is socially acceptable and
environmentally responsible
• Rainwater is friendly to landscape
plants and gardens
• It promotes self-sufficiency and
conserves water resources

12. DISADVANTAGES:
• Regular maintenance will be required for a
successful rainwater collection system.
• Quality of rainwater can be affected by air-
pollution, insects, and dirt or organic matter.
• Droughts or long periods of time with little or
no rain can cause serious problems with your
supply of water.
• The supply of water from a rainwater
collection system is not only limited by the
amount of rainfall but also by the size of the
collection area and your storage facilities.

14. ECONOMIC EFFICIENCY:
Valid data on the economic efficiency
of rainwater harvesting systems is not
possible. Dependent on the regional
conditions (water and wastewater
prices, available subsidies), the
amortization period may vary between
10 and 20 years. However, it should be
taken into consideration that for the
major investment (storage and pipe
work) a period of use of several
decades is expected.

16. CRITERIA FOR SELECTION OF RAINWATER HARVESTING:
• Type and size of catchment area.
• Local rainfall data and weather patterens.
• Family size.
• Length of the drought period.
• Cost of rainwater harvesting system.
When rainwater harvesting is mainly considered
for irrigation, several factors should be taken into
consideration. These include:
• Rainfall amounts, components of a rooftop
rainwater harvesting system.
• Soil infiltration rate, water holding capacity, fertility
and depth of soil.

18. RAINWATER HARVESTING PRACTICE IN INDIA:
At the rate in which India’s population is
increasing, rainwater harvesting is the need
of hour.
In the state of Tamil Nadu, rainwater
harvesting was made compulsory for every
building to avoid ground water depletion. It
proved excellent results within five years as
in Chennai saw a 50 percent rise in water
level and the water quality significance
improved.
The rain water harvesting campaign of the
Government and publicity by various media
is responsible for popularizing rain water
harvesting in the country.

20. CONCLUSION
The effectiveness of rainwater
harvesting system lies in its ability
to meet the site requirements.
Though simple, these systems are
site specific and need to be
detailed out before implementation.
With decrease in availability of
water, rain water harvesting
presents for the best option for the

21. TEACHER’S REMARKS
 Initiative cooperativeness and participation
______________
 Aesthetic presentation, visual appeal, expression
and neatness_________________________________
 Content accuracy, creativity, originality, analysis of
different perception
__________________________________
 Date of submission ____________________
 Total marks _____________________
 Overall remarks ______________
 Teacher’s signature _______________ Date