उपराज्यपाल, दिल्ली

As part of the comprehensive plan to revive River Yamuna, the Hon’ble Lt. Governor undertook the task of cleaning the 57 km long Najafgarh Drain, which is the biggest polluter of Yamuna in Delhi. This resulted in the first ever scientific operation to rejuvenate Najafgarh Drain by cleaning and desilting the drain through a cost-effective scientific concept of Partial Gravitational De-silting process. A sustainable and cost effective cleaning measure, this concept ideated from Shri Saxena’s experience of dredging in the ports of Gujarat.

In just over 6 months, 17 km of stretch has been completely cleaned and the discharge of as many 32 subsidiary drains into Najafgarh Drain has been checked. As a result, the BOD levels in Najafgarh Drain registered a decline of up to 30 per cent in just 4 months. The reduction of BOD is the sign of self-healing power of the river and the drain.

Partial Gravitational De-silting process is a departure from the conventional method of de-silting that entails removing the silt using barges and depositing the silt on the embankments, from where most of the silt would again flow back into the drain. This technique uses the flowing water in the drain itself to take the silt away by loosening and churning of the silt instead of  physically removing it, as was being done till now. Churning of the thick silt deposit is being done with the help of nonconventional floating equipment and contraption modified with raker and spikes attached to the boats. The modified equipment is dragged inside the drain by the boat and it, in turn, churns and loosens the silt and the suspended silt is subsequently taken along by the flowing water, thereby effecting natural de-silting.