Eco-restoration of Vembanad in limbo. Water-carrying capacity of the lake has shrunk by 78%, find studies

The Thanneermukkom barrage across the Vembanad lake.

Among a slew of projects announced by the government for flood management in Kuttanad in the wake of the 2018 deluge was a proposal for the eco-restoration of Vembanad Lake, a Ramsar site. The project aimed at increasing the waterbody’s absorption capacity, ensuring that the floodwaters brought into the area by rivers flow uninterruptedly to the sea, has not reached anywhere. Various studies have found that the water carrying capacity of the lake has shrunk by 78% over a period of time.

Major reason

A study by the Central Water Commission observed a drastic reduction in the carrying capacity of the lake as one of the factors that led to the flood in Kuttanad. The report ‘A special package for post-flood Kuttanad’ prepared by the State Planning Board stated the “shrinkage of surface area and depth of the lake is a major reason for the acuteness of Kuttanad floods.” “As much of the monsoon water could be stored in the lake itself earlier, a decline in the size of the lake intensified the risk of flooding in Kuttanad. The major reasons for the decline in the water spread area were unchecked encroachments, reclamation of the lake area and the rise of the lake bed due to silting,” the report noted.

In the State Budget for 2020-21, the government announced that the absorption capacity of backwaters would be enhanced by mechanised lifting of muddy sludge, for which ₹10 crore was earmarked. Besides, the budget also proposed a “massive scheme” with financial assistance from the Kerala Infrastructure Investment Fund Board to remove sludge and sediment from the lake and canals linked to it. The succeeding budgets also saw funds being set aside for the lake cleaning activities.

Now, almost four years after the deluge, Vembanad remains silted, heavily polluted and infested with invasive aquatic weeds. “Vembanad Lake desilting is a multi-year project spread across several districts. Discussions have been taking place at various levels of the government but the physical work has not yet begun. We are awaiting a report on the lake from the Kerala University of Fisheries and Ocean Studies. Once the report is available, we will prepare the detailed project report,” said an Irrigation Department official.

Desilting

While the lake desilting remains on paper, declogging and desilting of canals/drainage channels and bund strengthening activities are making slow progress in Kuttanad. The deepening of the leading channel of the Thottappally spillway, renovation of the spillway shutters and the proposal to keep open the shutters of the Thanneermukkom bund at least for one year for cleaning Kuttanad by letting in saltwater remain unfulfilled. Desilting of rivers including Pamba, Meenachil, Achankovil and Manimala as part of the Room for River project is making progress, albeit slowly.

The official said the government had accorded administrative sanction for a ₹70 crore project for bund formation and deepening of the channel from Veeyapuram to Thottapally. The department has submitted a project worth ₹58 crore for eco-restoration of areas upstream of Vembanad Lake to the government.