NEW DELHI: Lieutenant Governor Vinai Kumar Saxena Tuesday took a motor boat to enter and inspect the ongoing cleaning drive at the Najafgarh drain, lying on the Delhi-Haryana border, with a relatively new technique – partial gravitational de-silting, which is different from the conventional way of de-silting, said, officials.
The technique was introduced recently as a sustainable and cost-effective cleaning measure. It came about after the LG introduced it here from his experience of dredging in the ports of Gujarat and is a departure from the conventional method of de-silting that entails removing the silt through barges.
Saxena entered the drain in a motor boat near Punjabi Bagh and spent over an hour inspecting the dredging work which uses floating equipment. The LG had in June asked officials from the irrigation and flood department, under whose jurisdiction the drain falls, to work on cleaning the drain and turning it into an eco-tourism hub.
The concept of partial gravitational de-silting uses the flowing water in the drain itself to take the silt away by loosening and churning the silt instead of physically removing the silt, as is being done now. The churning of the thick silt deposit is being done with the help of non-conventional floating equipment and contraption modified with raker and spikes attached to the boats.
The modified equipment is dragged by the boat and it in turn churns and loosens the silt. If the flow of water is fast enough, then the suspended silt can easily be taken along, thereby affecting natural de-silting.
The Najafgarh Drain is 57 km long with as many as 121 smaller drains discharging sewage into it.