Rainwater Harvesting — Long Answer Questions and Answers (CBSE Class 10)
Medium (Application & Explanation)
1. What is rainwater harvesting? Explain its meaning, purpose, and key idea.
Answer:
- Rainwater harvesting is the collection and storage of rainwater.
- It stops water from simply running off and getting wasted.
- The main purpose is to recharge groundwater and store water for home and farm use.
- It reduces dependence on external water sources like tankers.
- The key idea is: “Catch water where it falls.”
- This idea makes water use local, cheap, and sustainable.
2. How does rooftop rainwater harvesting work? State its benefits with an example.
Answer:
- Rain falls on the roof and flows through pipes.
- The water is sent to storage tanks for immediate use.
- Or it is sent to recharge pits or borewells to refill groundwater.
- It suits both urban and rural homes and buildings.
- It reduces water bills and water scarcity.
- Example: Chennai and Tamil Nadu made rooftop harvesting mandatory, which raised groundwater levels.
3. What is surface runoff harvesting? Describe the structures used and their uses.
Answer:
- Surface runoff harvesting collects water from roads, parks, and open fields.
- The water is directed into check dams, percolation ponds, and storage tanks.
- Check dams slow water and help it percolate into the soil.
- Percolation ponds hold water so it seeps underground.
- It is useful in places with seasonal rainfall and open lands.
- It helps prevent floods, reduce erosion, and recharge aquifers.
4. What are recharge wells and percolation pits? How do they help groundwater?
Answer:
- Recharge wells are deep structures that take water to aquifers.
- Percolation pits are shallow pits that help water seep into the ground.
- They capture rainwater and stop it from being wasted.
- They slow down runoff and increase infiltration.
- They help stop declining groundwater levels.
- They are simple, low-cost, and eco-friendly solutions.
5. Describe traditional rainwater harvesting practices in different regions of India.
Answer:
- Rajasthan uses kunds and tankas to store rain in deserts.
- Himachal Pradesh & Jammu use kulhs to divert stream water to fields.
- Maharashtra builds bhandaras and tals as small check dams and ponds.
- Tamil Nadu has eris (tanks) linked in chains for irrigation and recharge.
- Gujarat uses virdas (shallow wells) to store freshwater in coastal sands.
- Meghalaya uses bamboo drip irrigation to carry water with minimal loss.
High Complexity (Analysis & Scenario-based)
6. Why is rainwater harvesting crucial for drought-prone regions? Use examples to support your answer.
Answer:
- Drought areas face low rainfall and high evaporation.
- Harvesting stores every drop and recharges groundwater.
- In Rajasthan, kunds, tankas, and johads help people survive dry months.
- Johad revival by Rajendra Singh raised water tables and revived streams.
- In Tamil Nadu, making rooftop systems mandatory improved groundwater.
- Thus, RWH brings water security, even with scarce and seasonal rain.
7. Your school faces water shortage and rainy-season flooding. Design a simple rainwater harvesting plan.
Answer:
- Collect roof water through gutters into storage tanks for toilets and gardens.
- Direct overflow to recharge pits near trees to refill groundwater.
- Build a small percolation pond on the playground to store runoff.
- Add silt traps and filters to keep systems clean.
- Involve the eco-club for maintenance and awareness drives.
- Result: lower water bills, less flooding, and better groundwater levels.
8. A coastal village in Gujarat faces salty groundwater. Suggest a community plan using local methods.
Answer:
- Dig virdas in sandy areas to collect fresh rainwater.
- Use rooftop harvesting to fill storage tanks for drinking needs.
- Direct excess clean water to recharge wells to build a freshwater lens.
- Avoid deep borewells that pull in salty seawater.
- Form self-help groups to manage ponds and maintain structures.
- Outcome: less salinity, more freshwater, and better health.
9. Compare community-led water management with large central projects. Which is better for villages?
Answer:
- Community systems use local knowledge and local materials.
- They ensure participation, ownership, and maintenance.
- Examples: johad revival in Rajasthan and Haryali program’s local works.
- They cost less and suit the local climate and culture.
- Large projects are costly and may ignore local needs.
- For villages, community-led methods are more sustainable and reliable.
10. How does rainwater harvesting reduce both floods and droughts? Explain with reasons.
Answer:
- It captures heavy rain and controls runoff.
- This reduces flooding and soil erosion in rainy months.
- Stored water and recharged aquifers help during dry months.
- It ensures steady supply for drinking and agriculture.
- It lowers demand on municipal water and tankers.
- Overall, it builds resilience against both floods and droughts.