Chilika Lake's Ecological Health Declines Again After Two Decades
In the year 2000, officials opened a new tidal mouth at Chilika Lake near Sipakuda. This action dramatically improved the lake's ecological health. Seawater exchange increased, salinity gradients revived, and fisheries and biodiversity recovered. The turnaround was so successful that Chilika became the first wetland in Asia removed from the Montreux Record due to verifiable ecosystem recovery.
Current Threats and Government Response
Now, two decades later, the lagoon's ecology faces new threats. According to state forest minister Ganesh Ram Singkhuntia's recent reply in the Odisha assembly, approximately 800,000 metric tonnes of muddy soil enters Chilika Lake every year. This sediment steadily layers the lagoon's mudflats and internal channels. The wetland is shrinking, even though it remains one of India's most celebrated coastal ecosystems and a Ramsar Convention site.
The government, with technical assistance from IIT Madras, is preparing to draw up a detailed project report worth Rs 2,000 crore. This report aims to restore the long-term health and productivity of the lake. A preliminary project report has already been presented to the state government recently.
Law and works minister Prithiviraj Harichandan and Puri MP Sambit Patra also met Union finance minister Nirmala Sitharaman recently. They sought central support for restoring the lagoon and redeveloping Chilika's ecosystem and tourism.
Technical Insights and Proposed Solutions
Monitoring data and local observations point to new ecological decline after twenty-six years. Amlan Nayak, divisional forest officer (Chilika wildlife division), stated that reopening or reconfiguring the mouth is essential to maintain salinity. He explained, "Salinity target is also tied to fish migration because many commercially important species depend on the lagoon-sea corridor at different life stages. Better exchange can reduce stagnation and weed proliferation."
Prem Kumar Jha, principal chief conservator of forests (wildlife), said the preliminary project report describes a system once again being squeezed by sediment and shifting coastal dynamics. He detailed, "Rapid siltation within internal channels, northward migration and narrowing of the tidal inlet, a declining tidal prism and increased freshwater dominance are together reducing the lagoon's salinity, balance and fish production."
At the heart of the proposed intervention is the lagoon's connection to the sea. The project report calls for opening a new tidal mouth based on detailed numerical model analysis. This would be alongside desilting critical internal channels, maintenance dredging, and detailed bathymetric and hydro-sedimentological surveys.
Jha further explained, "Chilika is a brackish water lagoon and its ecological character depends on a stable, predictable mixing of sea and freshwater. When the inlet migrates, narrows, or becomes hydraulically inefficient, seawater exchange weakens, salinity drops and the lagoon begins to behave more like a freshwater lake — inviting weed growth, stagnation and habitat shifts and in a ripple effect, changes the food web."
Engineering Challenges and Restoration Plans
CDA officials said the engineering challenge is complicated by the inlet's movement. The mouth opened in 2000 has shifted north by about 8km. The proposal is to create a suitable mouth through desilting. Amlan Nayak added, "Numerical model studies, combined with satellite imagery analysis, will be used to identify the best location and design, with details to be finalised in the detailed project report."
The proposed restoration also focuses on desiltation of channels inside the lake and from the lake to the outer channel. If this is carried out, officials said accumulated silt can be naturally flushed out during heavy rainfall. The rate of mouth migration can also be reduced.
The preliminary project report points out that 50% of the existing desilted channel needs further desilting. A bathymetry survey will determine the exact quantity and prioritisation. Periodical field studies have been proposed to estimate siltation and erosion rates in desilted channels. Maintenance desilting would occur once every two years.
Broader Impacts on Livelihoods and Tourism
The IIT proposal signals an improved methodology for disposal. This includes the creation of artificial islands with forest cover at disposal locations. If designed carefully, this approach can reduce secondary impacts while potentially creating new roosting or sheltering habitats.
The restoration blueprint extends beyond hydrology to livelihoods and tourism. It acknowledges that Chilika's resilience is inseparable from how people use it. Upgradation of fisheries infrastructure is proposed in response to gaps that directly affect incomes. These gaps include lack of modern landing facilities, post-harvest losses, and inadequate hygienic handling areas.
Chilika's flagship ecotourism activities have become livelihood anchors for local communities. Irrawaddy dolphin watching at Satapada and bird watching at Mangalajodi are a major part of Odisha's nature-tourism identity. However, increasing visitor pressure and unregulated boat traffic risk disturbing sensitive species and degrade habitats.
The plan calls for carrying capacity studies by an appropriate expert organisation. These studies would determine the maximum number of visitors and boats that can be accommodated without adverse impacts on dolphins, migratory birds, and wetland ecology. The preliminary project report seeks a governance model that integrates community custodianship and benefit-sharing. It aims to align habitat management with global benchmarks.
