Once known as the ‘City of Lakes’, Bengaluru now faces severe water shortages with demand outstripping supply as rapid urbanisation takes its toll. However student-led research project under the Anveshana initiative suggests that restoring the city’s historical lake system could help achieve water self-reliance.
Historically Bengaluru’s lakes functioned as interconnected reservoirs storing rainwater and supporting agriculture drinking water needs, and groundwater recharge. They also helped control floods by gradually releasing excess rainfall.
However over the decades, urbanisation and groundwater extraction led to widespread lake neglect and encroachment, with many turning into sewage dumps. The city, now reliant on importing water from the Cauvery River, faces a growing demand-supply gap that threatens its future sustainability.
Water Crisis Worsens as Demand Surges
Bengaluru’s population exploded from 4 million in 1991 to 8.5 million in 2011, with a projected 12.6 million residents by 2035. Today, the city’s water demand stands at 2,632 million litres per day (MLD), but only 1,800 MLD is available, creating a shortfall that will only worsen.
The study highlights that rainwater harvesting and lake rejuvenation could capture Bengaluru’s annual 4,220 billion litres of rainfall, reducing reliance on external water sources. However, with lakes in a degraded state, much of this potential goes to waste.
The research found that while the number of lakes declined by 14% from 2011 to 2024, there has been no significant reduction in total lake area. Instead, many lakes are now filled with urban wastewater, turning them into sewage reservoirs rather than functional water bodies.
Reviving Bengaluru’s Lakes: A Path to Water Self-Reliance
The student project proposes practical solutions to restore the lakes:
- Planned Excavation – Removing sediment layers to increase storage capacity and improve groundwater recharge.
- Catchment Area Restoration – Cleaning and maintaining inflow channels to reduce pollution and siltation.
- Community Participation – Encouraging local engagement in lake conservation efforts to ensure long-term sustainability.
Currently, half of Bengaluru’s water comes from the Cauvery River, costing approximately ₹37.8 million per day in supply expenses. Revitalising lakes reduces this dependence, offering economic savings while also creating jobs in lake restoration and sediment reuse for agriculture and industry.
Bengaluru’s lakes hold the key to sustainable urban water management. With scientific rejuvenation strategies, the city can bridge its water gap, reduce dependence on external sources, and create a replicable model for other growing urban centres. The student-led initiative underscores the urgency of reclaiming Bengaluru’s water heritage before it’s too late.