Bengaluru Apartments Lead the Way in Water Self-Sufficiency
Across Bengaluru, a growing number of apartment complexes are transforming their water management strategies to combat rising costs and scarcity. While many still depend heavily on water tankers and borewells, innovative communities are achieving near self-sufficiency through a blend of traditional conservation methods and modern technology.
Metropolis Gurukrupa: Rainwater as the Primary Source
At the Metropolis Gurukrupa apartment complex in Singasandra, residents have harnessed rainwater to meet their needs for about six months each year. By converting 100% of rooftop rainwater into potable-grade water, the complex has drastically reduced its reliance on external sources. Ganesh Shanbhag, a resident and water conservation advocate, emphasizes that rainwater should be the primary water source for all apartments. He notes, "Both rooftop rainwater and surface runoffs can be easily converted into drinking-grade water, allowing a complex to offset approximately half of its annual requirements." Located on the Deccan plateau, Bengaluru benefits from rains from both the Arabian Sea and Bay of Bengal, with Ganesh reporting over 1500mm of rainfall in the past year across 60-62 days. The complex even has the capability to convert excess flush water into drinking-grade water, showcasing advanced recycling efforts.
Century Saras: Technology and Traditional Wells Combine
The Century Saras apartment complex in Yelahanka has implemented a comprehensive water conservation plan that saves an impressive 1.26 crore litres of water annually. By introducing aerators, the complex reduced daily freshwater consumption by 7,000 litres. Padmashree C Pai, president of the all-woman management committee, explains that a cloud-based system enables 24x7 monitoring of water consumption patterns and leakages. The complex is also planning to automate its sewage treatment plants (STPs) to enhance monitoring of treated used water quality, with potential future sales of excess STP water for industrial use at a market cost of Rs 10 to 12 per unit, involving a capital expenditure of about Rs 18 lakh.
In addition to technological solutions, Century Saras has revived traditional water sources. The complex features an open well started in 2024, along with seven recharge wells that are 20 to 30 feet deep. Padmashree highlights, "The open well is a great source of water and helps mitigate flooding risks during the rainy season." Since 2017, the complex has reused 50% of treated water for flushing, with STP water quality being systematically tested to ensure it is odorless and colorless. Rainwater harvesting from 900 square feet of rooftop further contributes to their conservation efforts.
Victory Harmony: From Tanker Dependence to Conservation Success
Victory Harmony apartment complex in Cholanayakanahalli, Hebbal, was once notorious as the 'tanker apartment,' relying on ten tankers daily. Through dedicated water conservation measures, the complex has slashed its daily water usage from 75,000 litres to 45,000 litres, eliminating tanker dependence entirely. Devi Joseph, former president of the management committee, recalls how a committee of nine women led door-to-door engagements to implement changes, including the installation of aerators in every apartment.
Water meters played a crucial role in detecting leaks and wastage, especially in vacant flats and faulty flush systems. Committee members frequently monitored meters to pinpoint losses and collaborated with the Bangalore Water Supply and Sewerage Board (BWSSB) to improve Cauvery water supply. Devi expresses satisfaction that new management committee members are continuing this legacy of conservation.
CoEvolve Northern Star: Innovative Design and Sponge Zones
At CoEvolve Northern Star in Thanisandra, water conservation was integrated into the primary design focus. Measures included demand reduction through aerators and dual-flush systems, along with recycled water use for flushing and irrigation. Suhail Rahman, MD and CEO of CoEvolve Estates, implemented a low-power, low-maintenance STP designed to produce potable quality water. Although initial attempts to mix treated water into non-drinking uses faced stigma and were rolled back, the project has advanced with the creation of artificial "sponge zones" capable of absorbing up to 15 lakh litres of rainfall daily.
In a new project in Sarjapur, a water-scarce zone, CoEvolve aims to make the community water-positive within 2-3 years by sending 1-1.2 lakh litres per day of surplus treated water back into aquifers via irrigation and percolation. Suhail notes the potential for future water sales, highlighting the flawed decentralized STP model in Bengaluru, where many of the city's 4,000 STPs are poorly maintained due to unreliable vendors and community management challenges.
Key Takeaways and Future Directions
The success stories from these Bengaluru apartments demonstrate that a combination of rainwater harvesting, STPs, open wells, and technology can lead to significant water savings and cost reductions. Ganesh Shanbhag advocates for using drinking water generated from treated STP water as a sustainable alternative, noting that technology has matured to make this affordable. He also emphasizes the benefits of open wells, which act as both recharge and water drawing sources with lower energy consumption compared to tubewells.
As water scarcity intensifies, these initiatives offer a blueprint for other communities to follow, promoting environmental sustainability and financial prudence in urban living.
