Soma Enterprise has completed the strengthening of Koyna Dam in Maharashtra, three months ahead of schedule. This is India's first dam strengthening project which the company has completed in 21 months. The project was awarded to Soma Enterprise in joint venture with SSHPR, Russia, by the state water resources department at a cost of Rs 94 crore.
Strengthening the overflow portion of Koyna Dam was undertaken to make it safer and better equipped to face high intensity earthquakes in future. In the first year, the extended foundation block was to be excavated 25m deep and it was backfilled with concrete. The extension of energy dissipation arrangement and strengthening and raising of the guide walls was also done in the first year. The excavation was done at full capacity reservoir storage and in close vicinity of an operating powerhouse under controlled blasting.
In the second year, the work included providing concrete backing to the downstream portion in the overflow section of the dam. The strengthening has raised the storage level by 5 ft, which has increased the storage capacity of the dam by 6.5 tmc.
Work on the strengthening of the dam commenced in August 2004 and was completed in May this year.