RAINWATER HARVESTING - FREQUENTLY ASKED QUESTIONS AND ANSWERS
1. What is Rainwater Harvesting (RWH)?
RWH is the
process of collection of rainwater and storing it for future use.
2. How is RWH done?
Rainwater is
directly collected from the roof or open space and filtered before storing or
recharging to the ground.
3. What are the methods of RWH?
There are
three methods of RWH – Roof top RWH, Open space RWH and Ground Water Recharge.
4. What are the advantages of RWH?
Rainwater
Harvesting has many advantages:
·
Augments the existing water supply
·
Reduces water bill
·
Reduces effect of draught and flood
·
Improves ground water availability and
quality
·
Environment - friendly technique
5. Who can do RWH?
Any
individual or institution can do rainwater harvesting. If you are planning to
build a house, you can incorporate in the planning stage itself. If you have
one already, you can retrofit rainwater harvesting.
6. What is the cost of RWH?
The cost of
RWH depends on quantity of the rainwater collected and the purposes for which
it is required. It varies from Rs. 2,000/- to Rs. 50,000/- for
residential buildings.
7. What are the space requirements?
For a
residential building, a tank / sump of 5000 - 10000 ltr (5ft. x 6ft. x 6ft. -
10ft. x 6ft. x 6ft.) needs to be built for storing the rainwater. Bigger the
storage facility, longer will be the availability of rainwater.
8. How does RWH benefit me?
The benefits
of RWH:
·
Immediate fresh water availability
·
Reduces water bill
·
Reduced dependence on conventional water
supply
·
Better living environment
9. What about the quality of water?
Rainwater is
the primary source and is purest form of water. You can collect rainwater and
use it for drinking purposes. However, precautions need to be taken, to keep
the water free from contaminants on the roof, open space, during channeling and
storage.
10. Who can help me in RWH?
With a little
guidance, you can do RWH on your own. In case you need help you can contact an
architect or an engineer, who has knowledge of RWH. There are also
agencies and consultants who take up RWH on turnkey basis. You can contact
BWSSB & KSCST RWH Helpdesks at : 080 23341652, 080 23348848, 080
26653666, www.kscst.iisc.ernet.in/rwh.html
11. How long can I store the collected water?
Since water
does not get contaminated when it is stored away from sunlight and air, you can
store water that’s free from impurities up to six months.
12. How can I use the harvested rainwater?
Rainwater can
be used practically for all purposes.
13. What is the approximate quantity of rainwater I can harvest?
In a 100 sq.
mtr area with annual rainfall of 1000 mm (Bangalore rainfall), you can collect
one lakh liters of rainwater.
14. What could be the adverse effects of RWH?
If proper
care is not taken, the following adverse effects could result –
(a)
Contamination of water, if the rooftop is not clean, (b) Water logging, if
ground water is not recharged properly and (c) Flooding of roofs, if filters
are not properly designed and cleaned frequently.
15. Is it one time or recurring investment?
RWH system is
one-time investment. The storage facility is the single most expensive
component of RWH. Recurring expenditure are cost of cleaning the filter and
pumping of water.
16. Can rainwater be harvested in industries / institutions and
multistoried buildings?
Yes, since
the roof area and open area available are bigger, rainwater can be harvested on
a large scale and the amount of savings will be huge. In multistoried
buildings, it has to be a community initiative.
17. Flat or sloping roof - which is better suited for RWH?
Both types of
roofs are suitable for RWH.
18. Can the harvested rainwater be used
for recharge of groundwater (Borewell / open well)?
Yes, it can
be done. In fact, many dried wells have got a new lease of life after RWH.
19. Can a family live entirely only on rainwater?
Yes, it is
possible. In fact, there are many households which do not depend on public
water supply system.
20. Do I need to take any permission from any department or neighbours
to install a RWH system for Ground Water Recharge?
No permission
is required.
21. Can sewage or any other water pollute ground water?
If proper
care is not taken, leaking sewage pipes, nearby toilet soak pits and industrial
effluents can pollute groundwater.
22. Can I plan Rainwater harvesting to my building
on my own?
Yes, go to link: http://rwh-advisor.info an
App developed by KSCST and UNESCO, which is both available on Google play store
and web.
23. I need to see the RWH models
practically, where should I walk-in?
We have established in collaboration
with Bangalore Water Supply and Sewerage Board
(BWSSB) “Sir M Visvevaraya Rainwater Harvesting Theme Park” in 40th
cross, 8th Main, 5th Block, Jayanagar, Bengaluru. Experts
here will demonstrate and advise on RWH. Contact @ 08026653666 / 08023341652
24.
Where Can I get more information on water, energy and environment?
Visit the Blog link http://rainmanspeaks.blogspot.in you will get lots of write-ups with
Images and Videos.
AR Shivakumar
KSCST