1. CHAPTER 7 Environmental Studies, 2e
Water Resources
CHAPTER 7
Environmental Studies, 2e

2. The Story of Cherrapunji
Wettest place on earth
11.5 m of annual rain
Yet drought in non-monsoon months
Reason: Forests cut down

3. Villagers in Cherrapunji carting water from other areas

4. Water Prerequisite for life Cannot be substituted by anything else
Can be recycled and reused
Needed for economic growth, environmental stability, biodiversity conservation, food security and health care
Plenty of water on earth, but many millions face water scarcity.
Global water cycle provides us with fresh water every year.

10. Water Scarcity More than 1700 cu.m/person/year: No scarcity
Below 1000 cu.m.person/year: chronic water scarcity
By 2025, 48 countries expected to be in this category
By 2050, only 4 countries will not have scarcity

11. In India
5177 cu m in 1951
2464 in 1990
1820 in 2001

13. Reasons for Water Scarcity
Increasing demand:
Growing population
Rapid industrialization
Increasing irrigation needs
Growing cities
Reducing supply:
Pollution of sources
Depletion of aquifers,
Falling water tables due to excessive withdrawals
Uncertain rains due to climate change

14. An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt) from which groundwater can be extracted using a water well. 

16. People waiting for water

17. Table 7.1 Pattern of water use (Percentage of total water consumed by each sector)

18. Conflicts over Water
More than 200 water bodies are shared by two or more countries.
Hotspots: Nile, Euphrates-Tigris, Ganga-Brahmaputra, etc.
Inter-state disputes (e.g., Tamil Nadu and Karnataka over Cauvery water)
Yamuna- Sutlej between Punjab and Haryana
Industries vs. communities

19. Solutions to Water Crisis
Reduce demand:
Educate people to use less water
Install water-saving devices like self-closing taps and dual-flush toilets.
Use decentralised wastewater-recycling systems in homes, apartment blocks, campuses, and industries, using natural methods like planted filters.
Adopt composting toilets to save water and also to minimise the sewage disposal problem.

20. Solutions to Water Crisis (contd)
Adopt agriculture practices that require less water:
Replace water-hungry crops by those requiring less water
Promote crops that can tolerate salty water
Return to indigenous species that can withstand drought
Switch to organic and natural farming
Get more crop per drop: Use drip irrigation, sprinkler method, etc.
Persuade people to change to a vegetarian diet that would require less water for production.

21. Solutions to Water Crisis (contd)
Reduce industrial consumption through recycling, reuse and new water-efficient technologies.
Catch the rain where it falls
Retain water on land as long as possible through check dams and contour bunds allowing it to percolate into the ground.
Implement rain water harvesting in urban and rural areas
Restore traditional system of ponds and lakes.
Adopt decentralized systems of water supply and sanitation
Plan many small local catchments in place of large ones.
Implement a large number of small-scale schemes.
Adopt fairer policies
Give control of water sources to the community
Price water properly
Removing inequities in access to water

22. Water Footprint
Indicator that measures both direct and indirect water use of a consumer or producer.
Defined as the total volume of freshwater that is used to produce the goods and services consumed by the individual or community or produced by the business.
Water Footprint of a country = (Yearly amount of domestic water used to produce all goods and services consumed within the country) + (Yearly amount of virtual water in the goods and services imported into the country).

23. Rainwater Harvesting
Rural areas: checkdams to recharge wells and groundwater aquifers
Cities: Rooftop harvesting
Collect, filter, use
Normally fit to drink
Can also be used to recharge borewells
Discard first rain of monsoon
Keep roof clean

24. Rainwater harvesting in a house

25. Rajendra Singh beside a check dam in Rajasthan

26. Rajendra Singh (born 6 August 1959) is a well-known water conservationist from Alwar district, Rajasthan in India. Also known as "waterman of India", he won the Stockholm Water Prize, an award known as "the Nobel Prize for water", in Previously, he won the Ramon Magsaysay Award for community leadership in 2001 for his pioneering work in community-based efforts in water harvesting and water management. He runs an NGO called 'Tarun Bharat Sangh' (TBS), which was founded in 1975.

27. A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to counteract erosion by reducing water flow velocity.

29. Possible future technologies
Transport of water in huge bags through sea
Towing of ice bergs
New aquifers
Desalination technologies

32. water cycle
virtual water
Water Footprint
rainwater harvesting
check dam

33. Water is essential to life and is in most cases irreplaceable.
The water cycle helps us get a regular annual supply of fresh water.
There is only a finite amount of water in the world.
The paradox of the water situation is that there is scarcity amidst plenty, primarily due to the impact of human activities.
By the middle of the century, most countries in the world (and cities in particular) will be facing water scarcity. India will face severe problems.

34. Even places with heavy rainfall can experience water scarcity in other seasons, if water management is poor.
The world’s food security may be threatened due to shortage of irrigation water.
There could be future wars over water issues.
There are effective ways of conserving and reusing water, which can be followed by anyone.