Manipur: Loktak heading towards doom due to worsening water pollution

Imphal: Northeast India’s largest freshwater lake, Loktak in Manipur, is heading towards doom due to its worsening water pollution. This warning was served according to a finding in a recent study conducted by Dr. Eliza Khwairakpam, Assistant Professor in the Department of Environmental Science, Nagaland University. Salinity levels in the lake have risen dangerously because of the continuous drainage of raw sewage and saline water into the lake.

Loktak Lake, Manipur’s iconic freshwater ecosystem and a designated Ramsar Site, is at the receiving end of the uncontrolled agricultural expansion, human settlements, and shifting (Jhum) cultivation in the catchment areas, severely degrading the water quality of rivers feeding into the lake.

Nine major rivers, the Khuga, Western, Nambul, Imphal, Kongba, Iril, Thoubal, Heirok, and Sekmai, feed poor water quality linked to extensive Jhum cultivation covering nearly 42% of their basin to the Loktak.

The study published in the International Journal of Environment and Pollution analyzes the impact of land-use patterns—agriculture, forests, settlements, and Jhum cultivation—on key water quality parameters such as dissolved oxygen (DO), biological oxygen demand (BOD), and temperature across these major rivers.

The study found of degrading the water quality of rivers feeding into the lake, particularly the Nambul and Khuga rivers.

In contrast, the Iril and Thoubal rivers, flowing through forest-dominated regions, exhibited better water quality, demonstrating the ecological importance of natural vegetation in preserving freshwater ecosystems.

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Loktak, home to over 130 plant species and 400 animal species, has been on the Montreux Record, an international list of threatened wetlands, for years due to pollution, sedimentation, and declining aquatic biodiversity.

Stressing the need for community-based land management and tighter controls on agricultural runoff and waste discharge, Dr. Khwairakpam, in her findings, warns that unsustainable practices are not only threatening the environment but also the livelihoods of thousands dependent on the lake.

The study concludes that protecting Loktak is essential for sustaining fisheries, tourism, and hydropower in Manipur.