Precision Mapping Rewrites the Map on Bhakra Dam’s Silt Levels

A high-resolution study conducted by the Indian Institute of Technology (IIT) Ropar has revealed that storage loss due to silt accumulation in the Bhakra Dam’s Gobind Sagar reservoir stands at 19%—considerably lower than earlier projections by the Bhakra Beas Management Board (BBMB).

Led by Dr. Reet Tiwari, the team utilized a high-precision 30-meter resolution survey, marking a first for India. The study calculated an average annual siltation rate of 30 million cubic metres (MCM), staying below the original design threshold of 33.61 MCM per year. This demonstrates that the reservoir retains significantly more capacity than previously indicated by conventional surveys, which relied on widely spaced cross-sections.

The findings come as the BBMB plans mechanical desilting across the 6-billion-cubic-metre reservoir, inviting expressions of interest for excavation at Lunu in Bilaspur and Seer Khad in Una district, each containing an estimated 150 MCM of silt. Dr. Tiwari noted that ongoing desilting reports will be submitted soon and recommended repeating the survey every three years to map siltation patterns and enhance water availability for Punjab, Haryana, and Rajasthan.

News by Rahul Yelligetti.