Frequently Asked Questions on Rainwater Harevesting

Q 1. What is Rain Water Harvesting?
Rain water harvesting means collecting and storing rain fall (precipitation) at or near the location where it falls.

Q 2. What is the purpose of Rain Water Harvesting?
The purpose of rain water harvesting is to use rainfall as a source of water

Q 3. Where is the water stored?
Water is stored either in specially constructed tanks or in a subsoil/Aquifer or at both the places.

Q 4. What does it cost to store rain water?
The cost of collecting rain water in a storage tank depends on the type of structure, location, capacity and other parameters. generally, the cost varies from Re.0.50/- to Rs. 10.00/- per a liter.

Q 5. What are the different structures used for Rain Water Harvesting??
A) Following are the various types of structures used for storing rainfall.

  1. Stone work tank
  2. Brick work tank.
  3. R.C.C. Tank
  4. Ferro cement tank.
  5. Pond.
  6. Polyethylene sheet lined pond.
  7. Coconut fiber cement tank.
  8. Loose Stone bandhare.
  9. Soil bandhare
  10. R.C.C./Stone Bandhare
B)Following are the options / methods for collecting / storing rainfall in subsoil / aquifer :-
  1. Percolation trench.
  2. Percolation pit.
  3. Percolation trench with bore.
  4. Percolation pit with bore.
  5. Percolation pond.
  6. Vanarai bandhara.
  7. Loose stone bandhara
  8. Soil bandhara..
  9. Dugout sunken pond
  10. Subsurface dam.
Structures developed with the help of methods / options from(f) to (j) store water for few days to few months. Hence they areused both for storage and for recharge.

Q 6. Is rain water safe for drinking?
  • Properly stored "Roof Top Rain Water" can be used for drinking provided the following care is taken.
  • Rain water stored should not be exposed to sun.
  • No exposure to atmosphere.
  • Ferro cement tank.
  • It is also advisable that water be disinfected through chlorination before using it for drinking.
Q 7.How can rain water harvesting be useful for agriculture?
A portion of agricultural land (farm land) is used for storing water, will depend upon quantity of water required for farming / horticulture etc.

Q 8. Is it possible to use rain water for industrial purpose?
It is possible to use rooftop rainwater for industrial purpose after proper filtration (treatment). Run off rain water can also be collected in pond and then can be used for industrial purpose after proper treatment.

Q 9. Can Rain Water replace water supply for public utility?
  • Rain Water can replace water Supply in City, but to what extent will depend on the following. (at the least, it can meet a part of the water requirement of a city).
  • Annual average rain fall.
  • Density of population.
  • Ferro cement tank.
  • Geology and hydro geology of that area and many other factors.
Q 10. Is it possible to use rain water harvesting on mass scale?
It can be used at any scale but its utility will depend upon many other factors as described above.

Q 11. How much spaces is required to collect rain water?
It depends on the extent to which you desire to use rain water.Assuming normal conditions, around 5% to 10 % area is Sufficient to utilize most of the rain fall during the monsoon period or through the whole year.