CHANDIGARH: Due to increasing incidents of landslides during the monsoon season, a comprehensive study of the hillocks around the Bhakra dam is likely to be undertaken by Geological Survey of India (GSI) to assess rock strength, slope stability fault lines and drainage patterns.
Sources said that the BBMB is planning to sign Memorandum of Understanding (MoU) with Geological Survey of India (GSI) to conduct a comprehensive study of hills around the dam.
The Board has already written to GSI, and formalities for finalizing the MoU are currently underway.
The proposed survey by GSI is expected to assess slope stability, rock strength, fault lines and drainage patterns. Thus based on the findings, BBMB may undertake fresh reinforcement measures to safeguard both the dam and associated infrastructure.
Sources in the BBMB said that the proposed study is as a preventive step rather than a response to any immediate structural threat to the dam. The aim is to obtain expert recommendations on modern slope stabilization techniques, including rock bolting, retaining walls, improved drainage systems, and bio-engineering solutions.
The hillocks around the dam primarily consist of sedimentary and metamorphic rocks that are prone to weathering and erosion. As the Shivalik range is known for fragile slopes, loose debris material, and susceptibility to landslides, particularly during intense rainfall.
Sources added that a scientific reassessment of the slope stability is necessary to avoid future risks, as landslides have been recurring in the last few monsoons in the hills around the dam and the approach routes from Nangal. The hills around the dam and the approach routes from Nangal have witnessed recurring landslides over the past few monsoons.
Due to heavy rains multiple slope failures were trigged last year leading to the blockage of both road and railway tracks connecting Nangal to the dam site. These disruptions affected the movement of personnel and essential supplies. The debris and muck from these hillocks had even entered the power house complex of the dam. However, the BBMB managed to contain the situation in time, preventing any major operational disruption.
Sources further added that when in the 1950s the Bhakra dam was constructed across the Sutlej river the adjoining hills were reinforced using concrete supports and iron bars to stabilize vulnerable slopes. It has been almost seven decades since those reinforcements were put in place.
"Due to water seepage, wild growth, heavy rainfall and continuous weathering these structures might have weakened. The vulnerability of these hillocks have further increased due to more intensive rains, ’’ says experts and added that slope instability in such terrain can be triggered by heavy precipitation and seismic activity, as well as human interventions like road cutting and construction. The Bhakra dam is one of country’s tallest gravity dams, standing at about 226 meters and has a massive reservoir know as `` Gobind Sagar’’.