India, March 4 -- Buried beneath layers of sludge and neglect, the Najafgarh drain, once the Sahibi river, has emerged as a critical fault line in Delhi's flood control and pollution management system. A government-commissioned bathymetric survey has found that over 150 sub-drains from Delhi and Gurugram empty into the 57km channel, while nearly 9.1 million cubic metres of silt have accumulated on its bed.

Officials say the findings have laid bare the scale of deterioration and are now guiding an ambitious clean-up under "Mission Sahibi".

A senior official from the Irrigation and Flood Control (I&FC) department said they have begun desilting heavily clogged stretches on priority. "The objective is to ensure unobstructed flow of rainwate...