Water scarcity, multi-purpose dams, rainwater harvesting and sustainable water management
Water constantly renews through evaporation, condensation and precipitation. This makes it a renewable resource.
India receives ~4% of the world's annual precipitation, holds ~2.5% of world's water — yet supports ~18% of world population.
India's rainfall is highly seasonal & uneven — most falls in a few monsoon months, causing floods and droughts.
Per capita water availability is declining fast due to rising population, agriculture and industrialisation.
More people means more water for drinking, farming and industry. Also raises demand for food — needing more irrigation water.
Agriculture uses the most water. Water-intensive crops and free/subsidised power lead to over-pumping of groundwater.
Industries need huge amounts of water and energy. Hydroelectric power and manufacturing put pressure on freshwater.
Cities and dense housing colonies with their own pumping devices over-exploit groundwater resources.
Excessive tube-wells and pumping lower the water table, making groundwater harder and costlier to access.
Domestic sewage, industrial effluents and chemicals pollute rivers and groundwater — good water becomes unusable.
Stored water is released through canals to farms, boosting agricultural output round the year.
Falling water spins turbines to generate clean electricity — a major renewable energy source.
Provide drinking and industrial water to towns and cities located far from the source.
Reservoirs hold excess monsoon water, reducing downstream flooding during heavy rains.
Regulated flow supports inland water transport and movement of goods along rivers.
Reservoirs support fish breeding and become spots for tourism and water sports.
| Dam / Project | River | State |
|---|---|---|
| Bhakra–Nangal | Sutlej | Punjab / Himachal Pradesh |
| Hirakud | Mahanadi | Odisha (world's longest dam) |
| Sardar Sarovar | Narmada | Gujarat |
| Nagarjuna Sagar | Krishna | Telangana / Andhra Pradesh |
| Tehri | Bhagirathi | Uttarakhand |
| Rana Pratap Sagar | Chambal | Rajasthan |
Dams fragment rivers, making it harder for aquatic fauna to migrate and breed. Sediment gets trapped, causing poorer riverbeds downstream.
Reservoirs collect silt and sediment, reducing storage capacity over time and creating rockier riverbeds downstream.
Ironically, dams meant to control floods have triggered them by releasing excess water. Sediment build-up worsens flooding during heavy rain.
Large dams submerge land and forests, displacing local communities and tribal people who lose their homes and livelihoods.
Benefits (water, power) often reach large farmers and industries, while costs fall on the poor and displaced — causing social conflicts.
Over-irrigation from dams causes waterlogging and soil salinity, reducing land fertility in canal-irrigated areas.
Led by Medha Patkar. Opposed the Sardar Sarovar Dam over displacement of tribal communities and environmental damage.
Agitations by farmers over inequitable distribution of water and benefits from irrigation projects.
Objections raised over sharing of river water and benefits — e.g., Krishna–Godavari and Cauvery water disputes between states.
| Method / Structure | Region | Description |
|---|---|---|
| Guls / Kuls | Western Himalayas | Diversion channels that carry water from streams for agriculture. |
| Rooftop harvesting | Rajasthan (Bikaner, Phalodi, Barmer) | Rooftop rainwater stored in underground tanks called tankas for drinking water. |
| Khadins & Johads | Rajasthan | Inundation channels and small check-dams to harvest rainwater and recharge wells. |
| Bamboo drip irrigation | Meghalaya | 200-year-old system channelling stream water through bamboo pipes to plants. |
| Recharge through tanks | West Bengal (flood plains) | Inundation channels used to irrigate fields during floods. |
Underground tanks in almost all houses of Bikaner, Phalodi and Barmer. Connected to sloping rooftops that channel rainwater. Kept water cool in summer.
A village where households built rooftop rainwater harvesting structures to meet their water needs — a modern success story.
In Meghalaya, tribal farmers use bamboo pipes to drip-irrigate betel and black pepper plants efficiently.
Many states (e.g., Tamil Nadu) have made rooftop rainwater harvesting compulsory for all buildings by law.
Capture rainwater from rooftops and open spaces to recharge groundwater and store for reuse.
Treat and reuse wastewater for gardening, industry and flushing — reduces demand on freshwater.
Use drip and sprinkler irrigation instead of flooding fields — saves large amounts of water.
Fix leaks, avoid over-use in homes, and adopt water-saving habits in daily life.
Treat sewage and industrial effluents before releasing them into rivers and groundwater.
Restore tanks, johads and step-wells; encourage watershed development and afforestation.