Gaps in BWSSB data, public scepticism: Why rainwater harvesting is not popular in Bengaluru

Challenges in rainwater harvesting in Bengaluru

Representative image. Bengaluru is still the Indian city with the second highest number of RWH structures, after Chennai. Pic courtesy: KSCST

Kochu Shankar, a resident of Banjara Layout in Horamavu, has not had to buy water from private tankers this year, unlike the majority of households in the layout. The rainwater harvesting (RWH) system at his home routes rainwater from the rooftop to the borewell, recharging it and ensuring a year-round water supply for the two-member family.

Most residents in the layout have been buying water from private tankers over the past few months. Horamavu, part of the 110 villages added to Bengaluru city corporation limits in 2008, is not getting Kaveri water supply yet. Besides, with extensive digging of new borewells, many existing borewells have dried up, leaving residents without any water source.

“The cost of tanker water, which is usually Rs 400-600, has now increased to Rs 800-1,000. Tankers too arrive only after two days of booking, since water is unavailable with them,” says Shankar, past president of the layout’s Resident Welfare Association. A four-member family in the layout is now spending an average of Rs 2,500 for water every month.


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The city is expecting a water crisis by summer, with reduced water levels in dams this year owing to rainfall shortage.

Given that Bengaluru gets 900-1,000 mm of rainfall annually, the entire city can easily sustain 4-6 months on harvested rainwater alone, says Dr U T Vijay, Executive Secretary at the Karnataka State Council for Science & Technology. But, despite the clear benefits in terms of water availability and cost savings, most properties still don’t have functional RWH systems.

Water Supply Board has no clear data on RWH-mandated properties

Bangalore Water Supply and Sewerage Board (BWSSB) monitors RWH non-implementation in the properties that already have its connections. But due to gaps in data, it is not clear how many properties exactly are supposed to implement RWH.

The BWSSB Amendment Act, 2011, made RWH mandatory for all properties on plots measuring 60X40 sq ft and above, as well as for new properties coming up on 30X40 sq ft sites. Through regulations in 2015, penalties were introduced for non-compliant properties.

According to data that BWSSB shared with this reporter, the city currently has 10.8 lakh properties with water connections, but only 1.9 lakh (nearly 18%) of them have implemented RWH. Another 39,703  properties have been identified for non-implementation and are paying penalties every month. These properties include individual homes, apartments (each apartment is counted as a single connection), and commercial properties.

That is, as per BWSSB data, only a total of 2.3 lakh properties – 1.9 lakh plus 39,703 – in the city are considered to be legally required to have RWH. 

BWSSB Engineer-in-Chief Suresh B acknowledges that the number of properties that are actually required to have RWH would be higher than 2.3 lakh. The Board has data of properties on 60X40 sq ft and 30X40 sq ft sites that came up after 2011. “When they newly apply for water connections, we check if they have RWH,” says Suresh.

Though properties on 60X40 sites existing before 2011 should also have implemented RWH, data on these properties have not been captured fully. Besides, as BWSSB started levying penalties only after 2015, there were gaps in the data captured before this, says Suresh.

Setting up rainwater harvesting systems in Bengaluru
Representative image. While RWH can be set up at low cost in individual houses, for apartments, cost is a major deterrent. Pic courtesy: Biome

“We are planning to conduct a survey this December and January to identify older 60X40 properties without RWH. The survey will be done as part of regular water meter reading,” says Suresh, adding that this would bring more properties under the ambit of RWH rules. “People in older properties mention issues such as lack of space, we need to check this.”

Also, since BWSSB currently supplies water to only the core areas of the city, it is not tracking RWH implementation in an estimated nine lakh properties without water connections in the outer areas. BWSSB has no jurisdiction over these properties.

Average penalty of Rs 491 per property

Currently, the 39,703 properties with water connections that are identified as defaulters, are paying hefty monthly fines. In October, they collectively paid a fine of Rs 1.95 cr. That is, an average of Rs 491 per property.

The properties include both residential and non-residential ones, but BWSSB officials say that the defaulters would mostly be residential properties, as the penalty for non-residential ones is much higher. 

For residential properties, the fine is 25% of their water bill for the first three months of non-implementation, and 50% afterwards. For non-residential properties, this is 50% and 100% of their water bill respectively.

Many RWH systems dysfunctional

Shankar, and another resident Sunil V T, who have been promoting RWH in Banjara Layout, say that many RWH systems here have become dysfunctional. Most residents here had recently installed RWH structures when applying for Cauvery Stage V water connections, as per BWSSB’s mandate.

“Many installed the system for namesake only – they just fitted a filter at the end of the drain pipe coming from the terrace, and then connected it to the ground. These systems are not functioning,” says Shankar. “They also felt they may not need the RWH system as they would get Kaveri water soon. There is a lack of awareness; people feel it’s a waste of money.”

Sunil adds, “To get water connection, the resident should upload photos of the pipes and filter on BWSSB’s website, and BWSSB officials will inspect the property too. But they don’t check if the system is actually functioning.”

RWH expert S Vishwanath says the onus is on residents to build recharge structures without cutting corners so that quality-related issues (like silting of borewells) do not arise later. “There is no dearth of good-quality materials or knowledgeable plumbers in the market now. For an individual house, RWH can be done for amounts as low as Rs 5,000, and even if a high-quality filter is used, within Rs 15,000 (assuming sump does not have to be built anew),” he says.

Maintenance, costs considered deterrents

Some residents find routine maintenance of the structures difficult. Maneesh, a resident at Banjara Layout, says, “There are trees adjacent to a portion of my terrace, so bird droppings and leaves fall on the terrace frequently. Mud from the terrace garden is another issue. Before a sudden rain, I may not be available to clean the terrace quickly. The filter would also get clogged, and then water in the storage sump would start stinking after 2-3 days.” He has stopped using the RWH system, but is now planning to build a separation on his terrace so that rainwater from the cleaner portion can be harvested.

While RWH can be set up at low cost in individual houses, for apartments, cost is a major deterrent, says Satish Mallya of the Bangalore Apartments’ Federation. “For an apartment with less than 500 flats, RWH (excluding sump) will cost Rs 8-10 lakh.” Retrofitting is also a challenge for older apartments.


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“For many new apartments, the builders are installing RWH now, but the question is how well are they functioning,” says Mallya. While BWSSB has given guidelines on the capacity required for RWH structures, there is no penalty for not complying with these specifics. “The builder may just dig a pit of 5-10 ft depth, and during rains it will just overflow. Later, the residents will have to bear the costs of setting up a proper system,” says Mallya.

However, despite the slow rate of RWH implementation, Bengaluru is still the Indian city with the second highest number of RWH structures, after Chennai. 

While capturing the complete data of eligible properties will help BWSSB enforce the law better, Vishwanath believes that “expecting 100% compliance is not practical.” He says that a system of penalties may only lead to more people setting up dysfunctional structures. Instead, he suggests that a democratic consensus should evolve through education and communication among citizens. “RWH, along with desilting of some lakes, has already helped improve Bengaluru’s groundwater levels. We need to push the envelope further.”

For resources on rainwater harvesting (RWH) visit Karnataka State Council for Science and Technology (KSCST) and Urban Waters.

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About Navya P K 35 Articles
Navya has 12 years of experience in journalism, covering development, urban governance and environment. She was earlier Senior Journalist, Citizen Matters, and Reporter, The New Indian Express. She has also freelanced for publications such as The News Minute, Factor Daily and India Together. Navya won the All India Environment Journalism Award, 2013, for her investigative series on the environmental violations of an upcoming SEZ in Bengaluru, published in Citizen Matters. She also won the PII-UNICEF fellowship in 2016 to report on child rights in Kerala and Tamil Nadu. Navya has an MA in Political Studies from Jawaharlal Nehru University, and a PG Diploma from the Asian College of Journalism.