Bengaluru, once celebrated as the "City of a Thousand Lakes," is grappling with a severe environmental crisis: the rapid depletion of its lakes. Over the past five years (2020–2025), the city’s water bodies have faced unprecedented threats from urbanization, pollution, and neglect, transforming its landscape and threatening its water security. This SEO-optimized article explores the causes, impacts, and potential solutions to Bengaluru’s lakes depletion, shedding light on why this issue demands urgent attention.
The Alarming Decline of Bengaluru’s Lakes
Historically, Bengaluru’s lakes, built by dynasties like the Cholas, Hoysalas, and Kempe Gowda, were engineering marvels designed for water storage, irrigation, and groundwater recharge. In the 1960s, the city boasted around 262 lakes. By 2020, this number had plummeted to approximately 185, and recent estimates suggest only 168–173 remain under the Bruhat Bengaluru Mahanagara Palike’s (BBMP) jurisdiction, with many in dire condition. Over the last five years, the situation has worsened significantly.
- 2020–2021: Reports highlighted that 90% of Bengaluru’s lakes were polluted or encroached, with 98% showing signs of sewage inflow or land grabbing. A study by the Indian Institute of Science (IISc) noted a 70% drop in water spread area since 1973, a trend that continued unabated.
- 2022–2023: Urbanization surged, with built-up areas increasing by 1055% since 1973, choking lake catchments. The city’s green cover shrank from 28% in 2010 to 2.9% by 2023, reducing natural recharge zones.
- 2024–2025: By April 2025, 125 of nearly 800 lakes in Bengaluru Urban and BBMP limits had dried up completely, with 25 more on the verge. Lakes like Nallurahalli and Vibhutipura turned into makeshift playgrounds, underscoring the crisis.
Causes of Lakes Depletion in Bengaluru
The depletion of Bengaluru’s lakes over the past five years stems from multiple interconnected factors:
- Unplanned Urbanization:
- Rapid urban sprawl, driven by Bengaluru’s IT boom, has led to the concretization of lake catchments. From 2020 to 2025, residential and commercial projects encroached upon lakebeds, with notable cases in areas like Whitefield and Bellandur.
- Stormwater drains (rajakaluves) are often clogged or redirected, preventing water flow into lakes.
- Pollution and Sewage Inflow:
- Untreated sewage, estimated at 400–600 million liters per day, flows into lakes like Bellandur and Varthur, causing eutrophication and fires (e.g., Bellandur Lake fires in 2020 and 2023).
- Industrial effluents and solid waste dumping have rendered 85% of lakes unfit for use, per a 2024 Environmental Management & Policy Research Institute (EMPRI) study.
- Encroachment:
- Real estate development has claimed lakebeds for layouts, malls, and bus stands. By 2022, 159 of 202 BBMP lakes faced encroachments totaling over 1,000 acres.
- Historical examples, like Dharmambudhi Lake (now Majestic bus stand), set a precedent for ongoing land grabs.
- Neglect and Poor Governance:
- Lack of coordination among agencies like BBMP, Bangalore Development Authority (BDA), and Bangalore Water Supply and Sewerage Board (BWSSB) hampers lake restoration. For instance, Bellandur Lake’s desilting, ongoing since 2020, remains incomplete as of 2025.
- Funds allocated for lake rejuvenation (e.g., ₹131 crore by BBMP in 2023) are often spent on beautification rather than core issues like desilting or sewage diversion.
- Climate Change and Reduced Rainfall:
- Erratic monsoons, linked to El Niño and urban heat island effects, have reduced lake recharge. Karnataka’s rainfall deviation averaged -26% from 2022–2024, per India Today’s Data Intelligence Unit.
- Rising temperatures have increased evaporation rates, drying up smaller lakes faster.
Impacts of Lakes Depletion
The loss of Bengaluru’s lakes over the past five years has triggered cascading effects:
- Water Scarcity:
- With lakes drying, groundwater recharge has plummeted. By 2024, Bengaluru’s groundwater table dropped to 20–80 meters in areas like Hoskote, compared to 10–12 meters a decade ago.
- The city now relies heavily on the Cauvery River (1,460 MLD) and overexploited borewells, yet faces a daily shortfall of 1,172 MLD.
- Flooding:
- Encroached lakes and blocked drains exacerbate urban flooding. Peripheral areas like Mahadevapura saw severe inundation in 2022 and 2023 monsoons.
- Ecosystem Damage:
- Lakes like Ulsoor and Sankey have reported mass fish deaths (2020–2023) due to low dissolved oxygen from sewage. Biodiversity, including migratory birds, has dwindled.
- Water hyacinth, covering 60% of lakes like Hebbal, chokes aquatic life.
- Public Health:
- Polluted lakes breed mosquitoes, increasing vector-borne diseases. Toxic froth from Bellandur Lake has caused respiratory issues and damaged vehicles (2020–2024).
- Economic Costs:
- Residents spend heavily on water tankers (₹2,850 for 12,000 liters in 2024), burdening households. Fishing communities have lost livelihoods as lakes dry or become toxic.
Efforts to Combat Lakes Depletion
Despite the grim scenario, some progress has been made since 2020:
- Community Initiatives:
- Groups like Friends of Lakes and One Bengaluru for Lakes have revived lakes like Jakkur and Kaikondrahalli through community trusts, organizing events like “Kere Habba” to raise awareness.
- Citizen-led cleanups and tree planting have restored partial functionality to lakes like Puttenahalli.
- Government Actions:
- The BBMP rejuvenated 75 lakes by 2023, blocking sewage inflow in some cases. Six lakes, including those in Koramangala-Challaghatta valley, were reported full in 2024.
- The Karnataka High Court (2020–2024) has pushed for audits by agencies like NEERI to monitor lake health.
- Proposed Solutions:
- Experts advocate for decentralized sewage treatment plants (STPs) and constructed wetlands to filter inflows, as piloted at Jakkur Lake (2020–2022).
- Rainwater harvesting (RWH) is mandatory, but compliance remains low (96,000 of 1.96 lakh properties by 2023). Scaling RWH could recharge lakes.
- Desilting and regular maintenance, rather than cosmetic upgrades, are critical, per WELL Labs’ 2024 report.
The Road Ahead: Saving Bengaluru’s Lakes
To reverse the depletion trend by 2030, Bengaluru needs a multi-pronged strategy:
- Strict Anti-Encroachment Measures:
- Demolish illegal structures and reclaim lakebeds, as seen in the 2023 Munnekolalu Lake restoration (33 acres recovered).
- Use satellite monitoring to prevent new encroachments.
- Pollution Control:
- Enforce 100% sewage treatment before lake inflow. Upgrade STPs to handle the city’s 1,400–1,600 MLD untreated sewage.
- Ban industrial dumping and enforce waste segregation to reduce lake litter.
- Community Engagement:
- Empower local lake committees, as successful at Kaikondrahalli, to monitor and maintain water bodies.
- Promote environmental education in schools to foster a sense of ownership.
- Policy Reforms:
- Strengthen the Karnataka Lake Conservation and Development Authority (KLCDA) instead of merging it with other bodies, as proposed in 2023.
- Allocate funds transparently for desilting, wetland creation, and biodiversity restoration.
- Climate Resilience:
- Restore green cover to enhance recharge and reduce runoff. Bengaluru’s 1.5 million trees are insufficient for its 13.6 million residents (2024 estimate).
- Use treated wastewater to refill lakes, as piloted at Devanahalli tank in 2024.
Conclusion: A Call to Action
The depletion of Bengaluru’s lakes from 2020 to 2025 is a stark reminder of the cost of unchecked growth. Once the backbone of the city’s water security, these lakes are now symbols of environmental neglect. With 125 lakes already dry and more at risk, Bengaluru faces a tipping point. By prioritizing restoration, enforcing regulations, and rallying communities, the city can reclaim its legacy as a water-abundant metropolis. Act now—save Bengaluru’s lakes before they vanish forever.
Sources:
- Indian Institute of Science (IISc) studies, 2020–2024.
- WELL Labs reports, 2023–2024.
- Environmental Management & Policy Research Institute (EMPRI), 2024.
- Times of India, May 2024.
- India Today Data Intelligence Unit, 2024.
