Water: Sources, Storage and Saving

A Today you'll learn

Identify natural and human-made sources of fresh water
Understand methods of storing water safely and traditional water harvesting systems
Recognise waterborne diseases and simple water purification techniques (boiling, filtering)

B Let's understand

Water is one of our most precious natural resources. Although nearly three-fourths of Earth is covered with water, most of it is salty ocean water that we cannot drink. Fresh water comes from rain, snow, rivers, lakes, ponds, and groundwater tapped through wells, tubewells, and handpumps. Drinking contaminated water can cause diseases such as cholera, typhoid, and diarrhea. Water can be made safe to drink by boiling for 10-15 minutes or using clean water purifiers. In many parts of India, traditional stepwells (baolis), rainwater harvesting tanks, and bunds are built to store seasonal rainwater for year-round use.

C See it step by step

Example 1: Why can’t we drink sea water directly?

Sea and ocean water contains high amounts of dissolved mineral salts.
Drinking salty water dehydrates the human body and harms the kidneys.
Only fresh water from rivers, lakes, rain, and groundwater is fit for drinking after purification.

Example 2: What is rainwater harvesting?

Rainwater harvesting is the collection and storage of clean rainwater from rooftops and surfaces.
The harvested water is channeled into underground storage tanks or allowed to recharge the groundwater table.
This prevents rainwater from running off into drains and being wasted.

D Your turn

The main natural source of fresh water on Earth is:

Look back at "Let's understand" above for a clue.

E Ready to practise?

Key idea 1

Rain is the primary natural source of fresh water on Earth.

Groundwater is drawn up using wells

Groundwater is drawn up using wells, tubewells, and handpumps.

Boiling is the simplest

Boiling is the simplest, most effective way to kill harmful waterborne germs at home.

Stagnant water allows mosquitoes to breed

Stagnant water allows mosquitoes to breed, spreading diseases like dengue and malaria.

Key idea 5

Rainwater harvesting collects seasonal rain for storage and groundwater recharge.

Warm up

1. Name three natural sources of fresh water.

2. How is underground water brought to the surface for drinking and irrigation?

3. Why is boiling water considered a safe and effective purification method?

Practise

4. Name two diseases caused by drinking dirty, contaminated water.

5. What danger arises when dirty water is allowed to stay stagnant around houses?

6. What is a baoli (stepwell)?

Challenge

7. Explain two easy ways families can prevent water wastage at home.

8. Why is ocean water unfit for domestic use and agriculture?

Download worksheet (PDF)

Question 1: Name three natural sources of fresh water.

Answer: Rain, rivers, and freshwater lakes.

Question 2: How is underground water brought to the surface for drinking and irrigation?

Answer: Using wells, tubewells, and handpumps.

Question 3: Why is boiling water considered a safe and effective purification method?

Answer: Boiling kills disease-causing bacteria, viruses, and parasites present in water.

Question 4: Name two diseases caused by drinking dirty, contaminated water.

Answer: Cholera and typhoid (or diarrhea/dysentery).

Question 5: What danger arises when dirty water is allowed to stay stagnant around houses?

Answer: Mosquitoes breed in stagnant water, transmitting diseases like malaria, dengue, and chikungunya.

Question 6: What is a baoli (stepwell)?

Answer: A traditional Indian water reservoir with steps leading down to the water level, used to store rainwater.

Question 7: Explain two easy ways families can prevent water wastage at home.

Answer: 1) Fix leaking taps immediately; 2) Use a bucket and mug instead of a running hose for washing cars or bathing.

Question 8: Why is ocean water unfit for domestic use and agriculture?

Answer: It contains high levels of dissolved salts that make it undrinkable and poisonous to crops.