Rainwater harvesting in Bangalore- a journey

April 10, 2010

We started a journey on water harvesting in 1994 when we built our house and included rainwater harvesting in it.

One met the late Anil Agarwal at CSE and the great rain warriors of Chennai – Sekhar Raghavan, Indukanth Ragade, Jaygopal,Ramani. We started with one of the first rainwater harvesting for an Industry – Escorts-Mahle-Goetze- thanks to a fantastic manager Ajit Rao and Engineer- Chandrahekhar. One talked about it a lot , that it was relevant for Bangalore. Consider this article in The Hindu Business Line June 2002

Karnataka: Rainwater harvesting as people’s movement

Anjali Prayag

BANGALORE, June 14,2002

JUST think of this. If you have a rainwater harvesting facility installed in your house, one evening’s rain for two hours is enough to give 8,000 litres of water, which will suffice a family of four for seven days.

With Bangalore having about 60 rainy days in a year, it is estimated that residences with a 100 sq m roof can gather about 97,000 litres of water per annum which will take care of the water needs for about 200 days.

And look at the cost factor. The pipes cost about Rs 15 to Rs 30 per running foot and the storage systems about Rs 2 to Rs 3.50 a litre and the bends and elbows between Rs 20 and Rs 75, bringing the total cost to Rs 4000-Rs 5000.

According to Bangalore-based rainwater harvesting consultant, Mr S. Vishwanath, “When people are spending 15-20 lakhs on the building construction, this cost is miniscule.”

Assuming a 20-year life period for the structure, the cost per kilolitre works out to less than Rs 4 a kilolitre making it extremely cost-competitive. City supplies have a production cost of Rs 15 per kilolitre.

The process of rainwater harvesting would encompass catching rainwater, directing it to an appropriate location and filtering it, if required, and storing it for use. Storage could be in tanks, sumps, ponds or lakes. Recharging of ground water is also possible.

Mr Vishwanath who started the Rainwater Club in Bangalore says in a study by the Karnataka Government, `A conceptual framework for rainwater harvesting for Bangalore’, it was found that the city receives about 3,000 million litres per day of rainwater with an area of 1,279 square kilometres. Compare this to the nearly 1,500 million litres per day, which will be pumped in after the augmentation projects of the Bangalore Water Supply and Sewerage Board (BWSSB), now under construction.

Several residences, office complexes, schools and industries, about 1,000 in numbers, in the city are already reaping the benefits of this system. For example, the industrial unit of Escorts-Mahle-Goetze, located in Yelahanka, has a rooftop harvesting system for 1,280 square metres, which collects approximately 2.50 million litres of water. The system has been designed to collect about 62 million litres harvestable water. A cost of Rs 2.5 lakhs was incurred and when 62 million litres is collected, the savings will be to the tune of Rs 40 lakhs per annum in the water bills.

Similarly, the harvesting system at the Chemical Engineering Department in the Indian Institute of Science is saving about Rs 22,500 per annum for the Institute.

Realising the benefits of the system, the Bangalore Mahanagara Palike, has decided to adopt this technology in parks and gardens. Considering the fact that the city has 400 parks, the savings on water costs will be enormous. The Government is also considering making the harvesting system mandatory in all new construction projects (both residences and commercial).

But, says, Mr Vishwanath, instead of making it mandatory, the Government would achieve better results if an awareness campaign is started on the benefits of the system. “Concessions that were given for solar water heaters could be given here too.”

He feels this should be a people’s movement rather than a Government initiative as the Government has too many responsibilities to fulfil.

So, how is he promoting the concept among Bangaloreans? “Through architects, plumbers, contractors and we have started a Web site www.rainwaterclub.org which provides all the information to the public.’

The wbsite also started thanks to Priya at inika.com and Sharath Hegde. A lot of interns and trainees came and worked, usually for peanuts.:)

Sushma came and made 2 films…

Now it is mandatory in Bangalore and the rainwater revolution rolls on…



  1. we have a rainwater harvesting system in place in our residence at 503, 3rd main, ombr layout, blr 43, as recommended by Mr. Vishwanath about 7 years back ( he had sent someone from his office to visit our site and give suggestions) . How do we go about getting our system certified as a feasible one as required by the Govt Water Board. Looking forward to a response asap. Thx, Anitha K Shetty

  2. The BWSSB engineer who will come to inspect the system can be shown the entire thing. He will certify it. Hope this is asap enough 🙂
    Why don’t you send me some pictures of it?

  3. Dear Sir/madam,
    In one of my projects in Bangalore with an area around 950 sqm we intend to implement RWH methods for reuse of rain water in flushes.
    Please let me know how do i calculate the quantity of water that i could collect for reuse given teh location and size of teh building.


  4. Dear Sir/madam,
    In one of my projects in Bangalore with an area around 950 sqm we intend to implement RWH methods for reuse of rain water in flushes.
    Please let me know how do i calculate the quantity of water that i could collect for reuse given the location and size of the building.


  5. i am impressed and want to get on rain water harvesting plant in my house at bangalore. can u please get me the address / mob number at teh earliset
    regards sanjay

  6. please join your hands to the Better Water India.

    good luck and awaiting your replay for join with you.

    with warm regards.

    madhu joshi Dharwad

  7. Dear Sir,

    Thank you for providing basic details so that we can pass on the massage to others.

    Best regards,

  8. Hello Sir,

    We are looking to install rain water harvesting system in our apartment (Bangalore). Could you please pass on the details whom to contact?


  9. Sir, I need your help regarding Instalation of Rainwater Harvesting in our House ,so I request you kindly give some contacts to apporach for the same I am at Mysore.

  10. I want the name of a RWH Consultant in Bangalore approved by Bangalore Water Supply and Sewerage Board

  11. We are experts in installing Rain Water Harvesting Systems at Individual Homes, Commercisl Complexes, Layouts, Apartments, Factories and Industries. Please do contact us if you want to install RWH at youer preises.

    Enliven Environment

  12. sir, I have an independent house in Ramamurthy Nagar, Bangalore. I want to Install a rainwater harvesting system in my house. I don’t know whether it can be possible or not and how much it will cost for me. My construction area is 1250 sq ft and total area is 1410 sq ft. Can you please let me know if there is something that i can do with my house.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: