Bengaluru’s landscape has transformed dramatically from a network of tank-based villages to dense urban sprawl. Historically reliant on traditional water management systems, the city today has only 40% of its area connected to the sewerage network. Untreated sewage flows directly into lakes, causing widespread ecological degradation. Of the 200+ lakes in the region, fewer than 50 have been scientifically restored. Even restored lakes suffer rapid decline due to poor maintenance, cosmetic-only interventions, and a lack of genuine community involvement. The Water and Soil Lab at ATREE implemented a science-led, outcomes-focused pilot restoration programme in an urban lake in Bengaluru, developing context-specific benchmarks and deploying evidence-based Nature-based Solutions (NbS).

Challenges

• Untreated sewage inflow continues to degrade lake ecosystems despite restoration efforts.
• Restoration projects are assessed against unrealistic bathing-water standards, misrepresenting outcomes.
• Cosmetic interventions prioritised over ecological health lead to rapid post-restoration deterioration.
• Limited community engagement undermines long-term stewardship and sustainability.
• Absence of locally relevant benchmarks slows NbS adoption across rapidly urbanising regions.

Outcomes

• Development of context-specific benchmarks for lake health in Bengaluru
• Generation of water quality and biodiversity data across selected lakes
• Improved planning and implementation of Nature-based Solutions
• Strengthened collaboration with communities, policymakers, and institutions
• Creation of a data repository and policy briefs to guide restoration efforts