Exercise caution while desilting Ganga, advises experts panel

Ravi S Singh

Tribune News Service

New Delhi, May 21

A high-powered inter-ministerial committee constituted by the Water Resources Ministry has counseled caution while carrying out proposed desilting of the  Ganga from Bhimgauda (Uttarakhand) to Farakka (West Bengal) which is aimed at ensure its natural and optimal flow to help keep it clean.

The committee, headed by Madhav Chitale (Expert Member, NGRBA) on which secretaries of the Ministries of Water Resources and Environment were members, said in its report, “ Indiscriminate desilting works may result in more harm to ecology and environment flow.”

“Thus there is a need to evolve guidelines and better broad principles, which should be kept in mind while planning and implementing desilting works,” it said. The committee was of the view that erosion, sediment transport and siltation in large rivers like Ganga are very complex phenomenon and that their estimation has inherent limitation and uncertainties.

Sedimentation is mainly seen downstream of Bhimgauda barrage and near the confluences of tributatory rivers with Ganga. The discharge congestion, large scale sediment deposition and its negative effects are mainly seen downstream of the confluence of Ghagara and beyond, the report said.

The committee further said though desiltation works can improve hydraulic performance of the river, these have no direct role in improving environment flow in the river.

“On the other hand, indiscriminate desilting or sand mining would cause adverse impacts on the river e-flow.

Recognising the importance of sediment transport in rivers, it recommended principles to be followed. They include sufficient flood plains (lateral connectivity) without any hindrance to the flow. Instead of “keeping the silt away”, strategy to “giving the silt way”, should be adhered to.

Also, embankments, spurs and river training measures provided to protect the banks should not encroach upon the flood plans and delink the lakes, flood plains and other riverine environment from the river.