Water Resources
Water is abundant on Earth yet scarce where and when we need it. This Class 10 Geography chapter explains water scarcity, examines multi-purpose river projects with their benefits and drawbacks, and explores rainwater harvesting as a sustainable way to conserve water.
Learning objectives
- Explain water scarcity and its causes.
- Evaluate multi-purpose river projects.
- Discuss conflicts such as the Narmada Bachao Andolan.
- Describe rainwater harvesting methods.
Key concepts
Water scarcity
Although three-fourths of the Earth is covered with water, fresh usable water is limited. Water scarcity arises from growing population, expanding agriculture and industry, over-use, and pollution of available water. Scarcity can occur even in areas with plentiful rainfall if the water is overused or contaminated.
Multi-purpose river projects
Dams built across rivers for several purposes at once — irrigation, electricity (hydel power), water supply, flood control and recreation — are called multi-purpose projects. Examples include the Bhakra-Nangal and Hirakud projects. Jawaharlal Nehru called such dams the 'temples of modern India'.
Problems and conflicts
Despite their benefits, large dams have drawbacks: they submerge land and forests, displace people, disturb aquatic life, and can increase the risk of certain floods. They have sparked protests, such as the Narmada Bachao Andolan, which opposed the displacement and environmental damage caused by big dams on the Narmada river.
Rainwater harvesting
Rainwater harvesting is the simple, sustainable method of collecting and storing rainwater for use. India has rich traditions of it, such as the tankas of Rajasthan, the bamboo drip irrigation of Meghalaya and johads. Rooftop rainwater harvesting is widely used today to recharge groundwater and meet local water needs.
Key definitions
- Water scarcity
- Shortage of water relative to demand, due to overuse or pollution.
- Multi-purpose project
- A river project serving several purposes such as irrigation and power.
- Rainwater harvesting
- Collecting and storing rainwater for future use.
- Tankas
- Underground tanks in Rajasthan used to store rainwater.
Solved examples
Q1. Who called dams the 'temples of modern India'?
Solution: Jawaharlal Nehru.
Q2. Which movement opposed big dams on the Narmada?
Solution: The Narmada Bachao Andolan.
Q3. Name a traditional rainwater storage structure in Rajasthan.
Solution: Tankas (underground tanks).
Common mistakes to avoid
- Thinking water scarcity occurs only where rainfall is low.
- Listing only irrigation as the use of multi-purpose projects.
- Forgetting the social and environmental costs of large dams.
- Confusing rooftop harvesting with river projects.
Water Resources — MCQ Quiz
10 questions with instant feedback. Use number keys 1–4 to answer.
A river project serving many purposes at once is a:
Practice questions
Short answer
What is a multi-purpose river project?
A dam project serving several purposes like irrigation, power and flood control.
What is rainwater harvesting?
Collecting and storing rainwater for future use.
Name the movement against Narmada dams.
The Narmada Bachao Andolan.
Long answer
What are multi-purpose river projects, and what are their benefits and drawbacks?
Multi-purpose river projects are large dams built across rivers to serve several purposes at the same time, such as irrigation, generation of hydroelectric power, water supply for homes and industry, flood control, navigation and recreation; examples include the Bhakra-Nangal and Hirakud projects. Their benefits are considerable: they store water for farming, produce clean electricity and help control floods. However, they also bring serious drawbacks. They submerge large areas of land and forests, displace many people from their homes, disturb the natural flow and aquatic life of rivers, and in some cases increase the risk of floods or earthquakes. These costs have led to protests such as the Narmada Bachao Andolan, showing that the gains of big dams must be weighed against their social and environmental impact.
Explain rainwater harvesting and give examples of traditional methods in India.
Rainwater harvesting is the simple and sustainable practice of collecting rainwater where it falls and storing it for later use, helping to overcome water scarcity and recharge groundwater. India has a long and rich tradition of such methods suited to local conditions. In the dry region of Rajasthan, people built underground tanks called tankas to store rainwater for drinking. In the hilly state of Meghalaya, an ingenious bamboo drip irrigation system carries water to plants. In many regions, structures like johads and ponds collected runoff. Today, rooftop rainwater harvesting is widely promoted in towns and cities, where rain falling on roofs is channelled into storage or used to recharge wells and groundwater, making communities more self-reliant in water.
HOTS (Higher Order Thinking)
Why can water scarcity exist even in regions of good rainfall?
Because heavy use by a large population, agriculture and industry, along with pollution of available water, can make even plentiful water insufficient or unfit for use.
Why is rainwater harvesting often better suited to local needs than big dams?
It is low-cost, decentralised, causes little displacement or environmental damage, and recharges local groundwater, directly serving the community that collects it.
Quick revision
Revision notes
- Water scarcity: from population, overuse, pollution (even with rainfall).
- Multi-purpose projects: irrigation, power, flood control (Bhakra-Nangal, Hirakud).
- Big dams displace people, submerge land → Narmada Bachao Andolan.
- Rainwater harvesting: tankas (Rajasthan), bamboo drip (Meghalaya), rooftop.
Key takeaways
- Fresh water is limited and unevenly available.
- Big dams have both benefits and serious costs.
- Rainwater harvesting is sustainable and local.
Frequently asked questions
What causes water scarcity?
Population growth, over-use by farming and industry, and pollution.
Why are some people against large dams?
They displace communities, submerge land and forests, and harm rivers.
What is rooftop rainwater harvesting?
Collecting rain from rooftops to store or recharge groundwater.