Reviving Manchhar Lake

Freshwater inflow has declined significantly relative to saline, toxic effluents discharged into it

Manchhar Lake, once famed for its abundant natural resources and its unique boat houses, is a poor shadow of itself having gradually lowered its freshwater intake at the cost of saline and toxic effluents. The lake’s status as a principal feeding and resting ground for migratory birds from Central Asia has changed as well. The environmental degradation of Manchhar Lake has had a profound impact on the livelihoods of the local communities. The dwindling fish catch is insufficient for the needs of fisherfolk today. Their average monthly household income in the area ranges between Rs1,000 and Rs3,000.

Speakers at a workshop held at Mehran University of Engineering Technology Jamshoro on Manchhar Lake have faulted irresponsible human interventions for the environmental tragedy there. The lake can still be saved if earnest efforts are made to stop the disposal of drainage effluent into the freshwater body, according to the findings of a research study on the environmental degradation of Manchhar Lake. This is possible when the Right Bank Outfall Drain is ready. Nai Gaj or hill torrent is one of the major sources of freshwater of the lake and impacts of Nai Gaj dam on Manchhar Lake would be crucial. It is imperative that the required allocation of water from Nai Gaj dam for Manchhar Lake should be ensured.

Another option could be to treat Manchhar Lake as a small dam and provide it with a spillway above the high flood level of the Indus. A comprehensive management plan for Manchhar Lake should be prepared with the participation of local communities and experts. The plan should recognise the rights of local communities over the lake’s natural resources and should include a long-term conservation and sustainable use plan for the lake and its resources and alternative income-generation options.

In addition, its unprotected status is a contributing factor to the wetland’s unabated exploitation and deterioration. The classification of Manchhar as a protected wetland under the Ramsar Convention and strict enforcement of the Wildlife Act must be ensured. These actions will help in reviving protecting and conserving this natural treasure of Sindh.

Historically, Manchhar Lake’s pollution concerns go back to 1921 when the Main Nara Valley (MNV) drain, which was originally designed as an inundation canal, was remodelled to transport raw sewage from the towns of upper Sindh and parts of Punjab. The remodelled MNV drain became the only source of drainage along the right bank of Sukkur Barrage. During the implementation of the Right Bank Outfall Drain (RBOD) project, the MNV drain was further widened and remodelled to drain the saline water pumped by the tube wells of the Salinity Control and Reclamation Project (SCARP). This development exacerbated the toxic content of the effluents being drained into the lake.

Meanwhile, the construction of dams, for water storage and power generation, and diversions upstream, for agricultural purposes and use by industries, on the River Indus led to water shortages downstream, which in turn reduced the amount of freshwater flowing into Manchhar Lake. At present, the waters of Manchhar Lake boast high levels of toxicity and salinity, which have had a ruinous effect on the lake’s natural habitat and biodiversity. The disposal of untreated effluents and other pollutants have been dumped into the lake, which has poisoned the water. This has severely affected the flora, fauna and aquatic life.

In 1988, wildlife authorities recorded the presence of up to 50,000 birds representing 102 species of migratory and resident birds at Manchhar. The lake was also home to 29 species of aquatic plants, 11 tree species and 17 varieties of crops. But as time passed outward migration intensified and is increasingly transforming into permanent relocation. The main reason for this phenomenon is the deteriorating quantity and quality of fish catch and diminishing opportunities for agriculture and other income-generating activities.

Over the last two decades, the freshwater inflow into the lake has declined significantly relative to the saline and toxic effluents discharged into it.

Published in The Express Tribune, October 15^th, 2017.

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