Chilika Lake, spanning 1065 sq.km along the eastern coast of Odisha, is Asia’s largest brackish water lagoon and a designated Ramsar Site, hosting over 800 recorded species and critical habitats, including several rare and endangered species listed in the IUCN Red List. The lagoon plays a critical role in the ecological balance and sustains the livelihoods of nearly 0.2 million people across 192 fishing villages. However, the ecological integrity of this globally significant wetland is under mounting pressure due to rapid urbanization, particularly from the capital city of Bhubaneswar, a fast-expanding urban center, located 98 km away. The city discharges wastewater through eleven natural drains that merge into the ‘Gangua Nallah water canal’, ultimately feeding into the Daya River, which flows directly into Chilika Lake. While the city has installed five sewage treatment plants (STPs), only about 30% of wastewater is treated, the remainder flows untreated, contaminating the water ecosystem.
In response to a directive from the National Green Tribunal, the Government of Odisha constituted a multi-stakeholder Task Force to assess the pollution load and implement corrective measures. The study mapped multiple contributors to the pollution—including unregulated industries, insufficient solid and biomedical waste management, and poor enforcement of environmental regulations. Key stakeholders identified include Bhubaneswar Municipal Corporation, WATCO, IDCO, the State Pollution Control Board, the District Medical Office, Drug Control Department, and the Water Resources Division.
Of 935 industrial units surveyed, 474 were found operating without valid consents, and 20 lacked effluent treatment plants. Approximately 50000 urban households, along with an additional 444 slum pockets remain unconnected to the sewer network. Nature-based solutions were piloted, such as in-situ drain treatment and stabilization ponds. WATCO initiated the acquisition of 44 acres land to construct an additional STP at the confluence of the Gangua and Daya Rivers. A critical component includes adoption of a community-based monitoring system to prevent illicit discharges and foster behavioural change. These interventions collectively aim to enhance governance, support inclusive planning, and reduce ecological degradation. The strategy focuses on source-to-sea pollution management, coordinated stakeholder action, policy reform, and community-based monitoring systems. These integrated efforts are aimed at restoring Daya and Chilika’s health, preserving its ecosystem, and sustaining the livelihoods that depend on it, offering a scalable governance model for integrated lake basin management in India and beyond.