This document discusses the importance of saving water and various methods for doing so. It notes that only 0.3% of water is fresh water available to humans, yet we pollute it and fail to consider people suffering from water scarcity. Dams and water harvesting are presented as two key methods. Dams allow for water storage but can displace people and harm the environment. Water harvesting through watershed management and traditional systems helps recharge groundwater, benefits communities, and is more sustainable than large dams. The document promotes raising awareness of water issues in observation of World Water Day each March 22nd.

1. Biology,
water for all. Done by – Mrinali
Grade – X

2. Contents
• Why water?
• How do we save? *methods*
• Dams
• Water harvesting
• Video
• Thank you! 

3. Why water? Why do we need to
save it?
• Well, to answer that water is the most necessary
source/ compound one needs in their life.
• All life forms require water.
• Only 0.3% of water is fresh water which is available
to us!

4. • Do we pollute them too?

6. • Do we need use it and forget about the people in
different parts of the world suffering from scarcity
of water?

8. A study
• Rains in India are largely due to the monsoon.
• Rain fall is received only for a few months in the
year.
• Failure of sustain water availability underground
has resulted largely from loss of vegetation cover,
diversion for high demand of crops, pollution from
industries and also not to forget urban wastes.

10. • Irrigation methods like dams, tanks and canals have
been used in various parts of India since ancient
times.
• There were managed by the local people to meet
their requirements for both agriculture and daily
needs (throughout the year) .
• They would store water .
• Cropping patterns would defer due to the
availability .
• Maintain the irrigation system.

12. DAMS
• Dams are massive barriers built across rivers and
streams to confine and utilize the flow of water for
human purposes such as irrigation and generation
of hydroelectricity. This confinement of water
creates lakes or reservoirs.

14. • Large dams can ensure the storage of adequate
water not just for irrigation, but also for generating
electricity, etc.
• Canal systems from these dams can transfer large
amounts of water great distances.
• There is no equal distribution of water, thus people
living close to the water resource grow water
intensive crops like sugarcane and rice, etc.

15. Problems faced by man with
large dams
i. Social problems – they displace large number of
peasants and tribal's without adequate
compensation.
ii. Economic problems – they swallow up huge
amounts of public money without the generation
of proportionate benefits.
iii. Environmental problems – they contribute to the
loss of deforestation and loss of biodiversity.

16. Water harvesting
• Watershed management emphasizes scientific soil
and water conservation in order to increase the
biomass production.
• aim – is to develop primary resources of land and
water, to produce secondary resources of plants and
animals for use in a manner which will not cause
ecological imbalance.
• Increases the production and income of the
watershed community, but also mitigates droughts
and floods and increases the life of the downstream
dam and reservoirs.

18. • Various organisations have been working on
rejuvenating ancient systems of water harvesting as
an alternative to the ‘mega-projects’ like dams.
• These communities have used hundreds of indigenous
water saving methods to capture every trickle of
water that had fallen on their land; dug small pits and
lakes, put in place simple watershed systems, built
small earthen dams, constructed dykes, sand and
limestone reservoirs, set up rooftop water-collecting
units.
• This has recharged groundwater levels and even
brought rivers back to life.

19. • The advantages of water stored in the ground are
many.
• It does not evaporate, but spreads out to recharge
wells and provides moisture for vegetation over a
wide area.
• In addition, it does not provide breeding grounds
for mosquitoes like stagnant water collected in
ponds or artificial lakes.
• The ground-water is also relatively protected from
contamination by human and animal waste.

20. World water day – 22nd march
(every year)

21. THANK
YOU!
