Bhakra capacity down, BBMB may dredge dam bed, sell silt

Vijay Mohan

Tribune News Service

Chandigarh, September 11

With water storage capacity at the crucial Bhakra Dam reduced by almost one-fourth due to inflow of silt, the Bhakra Beas Management Board (BBMB) will explore options to dredge the reservoir bed and use the excavated silt for agricultural or industrial purposes.

“We will shortly be undertaking a study for assessing the composition and characteristics of the huge quantity of silt and debris that have accumulated over the years to determine its suitable use. Since silt is mineral rich, it could possibly be for used for agricultural or horticultural purpose or for making bricks or in other construction work,” a senior BBMB official said.

The modalities of the dredging operations, the agencies to execute the works, propriety issues and the commercial aspects would be worked out later.

Sources said the reservoir’s capacity had gone down by one-fourth (see box) since the dam’s “impoundment” (control of water flow) in 1958. “Since an estimated 38 million cubic metres (MCM) silt flows into the reservoir every year, the storage capacity would have gone down further during the past six years,” an official said.

The BBMB is in the process of conducting a fresh silt survey to assess the level of sedimentation in the Gobind Sagar reservoir that lies on the Sutlej. 

Periodic surveys have been done several times in the past, though Gobind Sagar has never been desilted. A large part of the dam’s catchment area, spread over 57,000 sq km, lies in the barren areas of Lahaul and Spiti district of Himachal Pradesh and Tibet. As a result, a lot of silt and loose debris get swept into its flow. Massive deforestation, cultivation and construction along the Sutlej’s course as well as along its tributaries and rivulets that feed the main river have added to the problem, especially during rains.