Water Resources

Water Scarcity - Reasons 

Conservation - How & Why 

Multi-purpose projects - Advantages, Disadvantages, and Objectives

Rainwater Harvesting - Techniques 

Map - Dams

Availability of water varies in time and space. 

Variations in the availabilities are caused by the variations in the seasonal and annual precipitations. 

Large and growing population. 

Industrialisation and cities are polluting fresh water. 

Over-exploitation of groundwater has caused a decrease in the water level. 

Excessive use, and unequal access to water resources. 

Water is being increasingly used for the generation of electricity, to fill ever increasing demand of industries and cities. 

To safeguard ourselves from health hazards. 

To ensure food security. 

For the continuation of our livelihoods and productive activities. 

To prevent the degradation of the natural ecosystem. 

To maintain sustainable development. 

Water harvesting system - Sringaverapura at Allahabad on the Ganga river - for channelising the flood water. 

Dams & Lakes - by Chandragupta Maurya - for irrigation 

Dams and Lakes - Kalinga, Nagarjunakonda, Kolhapur - for irrigation 

Artificial lake - Bhopal - for irrigation purposes 

Tanks - At Hauz Khas in Delhi by Iltutmish - Water Supply 

Flood control 

Navigation 

Water supply 

Hydroelectricity 

Recreation 

Irrigation

Loss of forest area 

Loss of cultivable land 

Difficult in relocation of people 

Disturbs ecological balance 

Earthquakes 

Water-borne diseases 

Poor habitat for aquatic life 

Excessive sedimentation 

Restricts natural flow 

High cost of construction 

Submerging of existing vegetation 

Rain Water Harvesting needs the collection and storage of rainwater for future use. It is done by building reservoirs, ponds, tanks, dug wells, and making check-dams. 

It is a viable alternative to multi-purpose projects, both socio-economically and environmentally. 

India has a long tradition of rainwater harvesting systems since ancient times. 

Different Techniques to Harvest:
1. Rainwater
2. Groundwater
3. River water
4. Flood water

Ancient techniques of rainwater harvesting.
[Technique - Region of practice]
1. Guls/Kuls - Western Himalayas
2. Roof-top water harvesting - Rajasthan and Meghalaya
3. Inundation channels - Plains of Bengal
4. Khadins or Johads - Jaisalmer (Rajasthan)
5. Tankas - Bikaner, Palodi, Marmer (Rajasthan)
6. Bamboo drip irrigation - Meghalaya

Construction of dams 

Linking rivers 

Creation of Awareness