New Delhi: Just a month after transforming into a grim ecological graveyard, Sanjay Lake in East Delhi is showing definitive signs of revival. Following an urgent intervention by local authorities, water levels in the artificial wetland have been successfully replenished, prompting a steady return of aquatic life and indigenous bird populations to the region.
In late May 2026, the 52 acre man made lake, located in the Trilokpuri and Mayur Vihar Phase II areas, became the site of a severe environmental crisis when thousands of fish died overnight. Shocking visuals at the time showed massive blankets of dead fish floating belly up across parched, receding sections of the lake bed. The die off heavily impacted a variety of species, ranging from small Gambusia (mosquitofish) to larger freshwater varieties like tilapia and carp.
Environmental experts and ground investigations revealed that the mass mortality event was triggered by a lethal combination of an intense summer heatwave high chemical and pollutant stagnation and a complete lack of water inflow. The crisis was severely compounded by a prolonged disruption in the lake’s primary water source a two foot diameter pipeline bringing treated water from the Dallupura Sewage Treatment Plant (STP), managed by the Delhi Jal Board (DJB), which had been suffering from unaddressed leakages. The lack of freshwater inflow paired with extreme temperatures caused the lake’s dissolved oxygen levels to plummet, effectively suffocating its aquatic ecosystem.
The ecological turnaround follows a recent high level intervention by Delhi Lieutenant Governor Taranjit Singh Sandhu, who inspected the deteriorating site and directed the Delhi Jal Board and the Delhi Development Authority (DDA) to fix the damaged pipeline in mission mode. With the pipeline successfully repaired and steady water inflow from the STP restored, the lake’s water levels have normalized, diluting the concentrated pollutant loads and oxygenating the water body.
The successful water replenishment marks the commencement of a broader, phased rejuvenation plan for the 52 acre lake and its surrounding 165 acre protected forest area. The DDA has initiated continuous de weeding, algae removal and embankment stabilization using geo textile technology to control soil erosion.
Moving forward, the phased revival strategy targets the installation of additional bio swales by August 2026 to improve groundwater recharge, followed by comprehensive bioremediation, aerators, and fountains by May 2027 to ensure optimal dissolved oxygen levels year round. To fully restore the vital green lung of East Delhi, authorities have also mandated the strategic planting of 5,000 native trees to permanently enrich the local biodiversity.