- No Bengaluru lake met potable or safe bathing water quality standards in 2025 tests
- Most lakes classified as severely polluted, unsuitable for human use by Karnataka board
- Bellandur, Varthur, Hebbal, and other major lakes rated in worst pollution categories
According to data published by the Karnataka State Pollution Control Board, water quality analysis conducted across 147 monitoring locations between April and November 2025 shows that not a single lake in the city consistently met potable or safe bathing standards.
No Lake Achieves Safe Water Quality
The report categorised lakes under standard water quality classes:
Class A: Potable without treatment
Class B: Safe for bathing
Class D & E: Severely polluted, unsuitable for human use
Shockingly, no lake achieved Class A or Class B status during the monitoring period. Most lakes were classified under D or E, indicating heavy contamination.
Iconic Lakes Among Worst Affected
Several of Bengaluru's most well-known lakes recorded disturbing pollution levels:
Bellandur Lake: Rated E in April, briefly improved to D during summer, before slipping back to E by November.
Varthur Lake: Fluctuated between D and E categories.
Hebbal Lake: Maintained D status for most months before deteriorating to E.
Other severely affected lakes include Madiwala, Kaikondanahalli, Kundalahalli, and Ulsoor (all D/E), while Sankey Tank maintained a D rating. The report notes that the Bommanahalli and Mahadevapura zones emerged as the worst-hit regions, largely due to rapid urbanisation and untreated waste discharge.
Experts Warn of 'Ecological Emergency'
Environmental activist Madhuri Subbarao, co-founder of Friends of Lakes, said the findings confirm long-standing concerns.
"Many lakes in Bengaluru are on the brink of ecological collapse," Ms Subbarao said. "Today, we cannot point to a single lake with healthy water quality, stable ecology, or safe biodiversity. Most lakes fall below acceptable standards, with water unfit even for animal consumption."
She called for urgent government intervention, including the formation of a dedicated lake restoration task force, the scientific identification of pollution sources, and stronger collaboration with citizen groups.
Summer Water Stress Likely to Worsen
The findings come at a critical time as Bengaluru prepares for peak summer, a period when dependence on groundwater and tanker supplies traditionally rises.
With the city's primary surface water bodies now officially declared unfit for use, residents face a mounting challenge in securing safe water as temperatures climb.
