Water Resources
3/4th earth’s surface - water - a small proportion - put to use
This freshwater - obtained - surface run off, ground water - renewed & recharged through
the hydrological cycle
Water scarcity
Water shortages - associate - low rainfall/drought prone
Availability- varies over space and time - variations in seasonal and annual precipitation
Cause - over-exploitation, excessive use & unequal access to water
Many of our cities have ample water resources but facing water scarcity. Why?
Large and growing population
Greater demands for water
Unequal access to it
A large population - more water for domestic use, more food production
Water resources - over-exploited - irrigated areas - dry-season agriculture
Irrigated agriculture - largest consumer
Developing drought resistant crops and dry farming techniques.
Farmers own wells and tube-wells - result in falling groundwater levels, affecting water
availability and food security
Post-independent India - industrialisation and urbanisation - creating vast opportunities for
us
Industries - exerting pressure - freshwater resources
Industries - require power to run - hydroelectric
Urban centres - large & dense populations & urban lifestyles - water and energy
requirements - aggravated the problem
Most of the housing societies - own groundwater pumping devices - water resources - over-
exploited – depletion
Atal Bhujal Yojana (Atal Jal)
8220 water stressed Gram Panchayats of 229 administrative blocks/ talukas in 80 districts of
seven states
Behavioural changes - attitude of consumption to conservation and smart water
management
Area has ample water resources, yet why water scarcity?
Polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers used in
agriculture
Jal Jeevan Mission (JJM)- every rural household - 55 litres per capita per day - tap water
connections
Water conservation
To safeguard ourselves from health hazards
To ensure food security
Continuation of our livelihoods and productive activities
To prevent degradation of our natural ecosystems
Over exploitation and mismanagement - impoverish - ecological crisis
Multi-purpose projects & water resources management
Ancient times - sophisticated hydraulic structures - dams built of stone rubble, reservoirs or
lakes, embankments and canals
•1st century B.C., Sringaverapura near Allahabad - water harvesting system channelling the
flood water of the river Ganga.
•Chandragupta Maurya, dams, lakes and irrigation systems were extensively built.
•Evidences of sophisticated irrigation works - Kalinga, (Odisha), Nagarjunakonda (Andhra
Pradesh), Bennur (Karnataka), Kolhapur (Maharashtra), etc.
•In the 11th Century, Bhopal Lake, one of the largest artificial lakes of its time was built.
•In the 14th Century, the tank in Hauz Khas -Iltutmish - Siri Fort Area
Dams
A dam is a barrier across flowing water that obstructs, directs or retards the flow, often
creating a reservoir, lake or impoundment
Dams - irrigation, electricity generation, water supply for domestic and industrial uses, flood
control, recreation, inland navigation and fish breeding
Hence - multi-purpose projects
For example, in the Sutluj-Beas river basin, the Bhakra – Nangal project - hydel power
production and irrigation
The Hirakud project - Mahanadi basin integrates conservation of water with flood control
Jawaharlal Nehru - ‘temples of modern India’
Integrate development of agriculture and the village economy with rapid industrialisation
and growth of the urban economy
Dams - scrutiny and opposition
Affect their natural flow - poor sediment flow and excessive sedimentation at the bottom
Rockier stream beds and poorer habitats for the rivers’ aquatic life
Fragment rivers - difficult - aquatic fauna to migrate, especially for spawning
Floodplains - submerge the existing vegetation and soil
Irrigation - changed the cropping pattern
Farmers - water intensive and commercial crops - salinisation of the soil
Dams - not controlled but triggered floods - sedimentation
Big dams - unsuccessful - excessive rainfall
Floods - devastated life and property - soil erosion
Induced earthquakes, caused water-borne diseases and pests and pollution
Rainwater harvesting
Hill and mountainous regions - diversion channels like the ‘guls’ or ‘kuls’ of the Western
Himalayas for agriculture
‘Rooftop rainwater harvesting’ - store drinking water, RJ
Flood plains of Bengal - inundation channels - irrigate their fields
Arid and semi-arid regions, agricultural fields - rain fed storage structures - water to stand
and moisten the soil - ‘khadins’ in Jaisalmer, ‘Johads’ in other parts of Rajasthan
Semi-arid & arid regions of Rajasthan, particularly in Bikaner, Phalodi and Barmer, almost all
the houses - underground tanks or tankas - storing drinking water
The tankas - rooftop rainwater harvesting system - connected to the sloping roofs
Rainwater, or palar pani, - purest form of natural water
Tankas to beat the summer heat
Today- rooftop rainwater harvesting - decline - Indira Gandhi Canal
In Gendathur, Mysuru, Karnataka - rainwater harvesting system - 200 households - - rich in
rainwater - net amount 1,00,000 litres annually harvested
Meghalaya - bamboo pipes drip irrigation
18-20 litres of water - gets transported over hundreds of metres - 20-80 drops per minute
