Check dams, including the Ramsar wetland of Sukhna lake, have a shelf life due to the silt load deposited in the monsoons from the fragile foothills. At the Siswan dam in Punjab, a desiltation project underway since December 2024 has not only augmented water flows into the dam’s eastern flank, but, by design or otherwise, altered the habitat in favour of biodiversity.

A series of ponds has been left in the wake of the silt excavation. These are ringed with tall reeds and bushes. Beyond their cover are mature trees on flanking hillsides affording perches and roosting spots for fish-hunting birds such as egrets, herons and raptors. The redoubtable Siswan habitat is lorded over by leopards.

The blend of shallow water and muddy shores in the ponds attracts resident and migratory shore, wading and water avians. Resident spotbill and lesser whistling ducks breed in these ponds after winter. This preferred wetland topography has gone missing at the Sukhna lake over the last decade due to its expansive waters, leading to declines in water-related birds, especially in winter, when transcontinental birds fly in by traversing the Central Asian Flyway.

Migratory species observed in the Siswan ponds over the last week by this writer include the common pochard (an IUCN vulnerable species), ferruginous duck (a near-threatened species), ruddy shelduck, gadwall, green-winged teal, Eurasian coot, and the white wagtail (an altitudinal/transcontinental migrant). Siswan’s diverse bird life is underscored by the fact that eBird India lists 147 species for Siswan lake. Even this is a conservative number, as species such as the black stork (a winter migrant from the Siberian Palearctic), the very rare greater scaup, the resident brown fish owl, and a number of other species strangely do not find a mention in the eBird list.

Apart from the benefits to waterfowl, the ponds and the lushness of the encircling flora support grass seed-eating birds. The foliage affords cover for sambar coming to drink at the ponds, as it dissuades predation by free-ranging dogs from peripheral villages. Opportunistic hunting by dogs has led to fawns being killed in great numbers in previous years, particularly when there were exposed, sticky-silt shore stretches leading to the drying dam. Yes, the desiltation has led to a disruption of ground-nesting birds but the ‘bigger picture’ requires the removal of silt for the long-term survival of the dam itself. A ready warning is served by the nearby Perch Dam, which is on the verge of its end of life, as the combined pressures of wind, water and silt threaten the very stability of the embankment, a mere three decades after its construction.

The above benefits would have come to nothing had the Punjab forests and wildlife preservation department dragged its feet further on acting on pending complaints of severe disturbance caused by a motley crowd in vehicles entering unfettered from the Siswan lake’s far shores. They indulged in alcohol and drug binges in the forest area, played loud music, littered unconscionably and undertook off-track jeeping to the detriment of the habitat. The threat extended to female birders of the Chandigarh Bird Club, whose forays with expensive cameras and binoculars to the Siswan lake no longer felt safe. However, the department recently blocked vehicle entry, to the relief of wildlife and birders.