Water: Sources, Uses and Saving: Class 4 Study Guide
Water is needed by every living thing. Only a small part of the world's water is fresh and ready to drink.
Most of Earth's water is in the oceans and is salty. Only a small part is fresh water, found in rivers, lakes, ponds, wells, glaciers and under the ground.
In India many villages and cities face water shortages in summer, so saving water matters.
Sources and uses
| Source | Where from | Used for |
|---|---|---|
| Rain | Clouds | Fills rivers, ponds and wells |
| Rivers and lakes | Surface water | Drinking, farming, fishing |
| Wells and borewells | Groundwater | Drinking and irrigation |
| Taps | A water supply plant | Home use |
Clean water
Water from rivers can have mud and germs. At a water treatment plant it is filtered and cleaned before it reaches taps. At home we can boil water, use a filter or add a purifying tablet. Dirty water spreads diseases such as diarrhoea and cholera, so we should keep sources clean and not throw rubbish into them.
Water is taken from a river or reservoir.
Mud and dirt are removed.
Germs are killed.
Pipes carry it to homes.
Saving water
We can turn off the tap while brushing, fix leaking taps, use a bucket instead of a shower hose, and reuse water from washing vegetables for plants. Rainwater harvesting collects rain from roofs into tanks or into the ground. Traditional systems such as johads in Rajasthan and stepwells in Gujarat did this for centuries.
Worked examples and common mistakes
Example: A tap drips one cup of water every 10 minutes. How many cups drip in an hour? 6 cups, and over a day that is 144 cups. Common mistakes: thinking that clear water is always safe, and leaving taps running.
Check your understanding: model answers
1. Rivers, wells and rain. 2. Boil it or use a filter. 3. Collecting rainwater for use.
✨ Key Takeaways
- Only a little of the world's water is fresh.
- Water is cleaned before it reaches homes.
- Dirty water spreads disease.
- Saving water and harvesting rain help.
💬 Questions for Discussion & Reflection
- Name three sources of water.
- How can we make water safer to drink?
- What is rainwater harvesting?