The new design incorporated a “worst scenario”, that is, the maximum possible rain in the upstream glacier lake, modeling by the Indian weather department, in the South Lhonak region for the next 100 years, which influenced modifications Additional downstream. File | Photo credit: Rij Konwar ritu.
Fourteen months after a devastating flooding in a glacier lake in Sikkim swept the Teesta-3 dam, the largest hydroelectric project in the state, and kill at least 100 people, a committee of experts from the Ministry of Environment recommended that the prey.
Instead of the old structure that was partly rock and partly concrete, the new dam will be entirely concrete (as reported to increase its resistance) and its spillway will be able to manage a maximum flow of 19,946 cubic meters per second (Cumecs ), Three times the capacity of the old dam, which was 7000 cumecs.
The project promoters, Sikkim Urja Limited (Sul), have also been asked to implement an early alert system in the upper basin, so that in case of flooding, the prey gates can be opened in time.
One of the main causes of “overflow” (dam rupture) was that the gates could not be opened in time and this caused a flood of water, rubble and mud. “If this had been possible, even the old concrete and rock dam would have survived. There would have been floods, but it could not have been so serious, ”said a government official aware of the process. The Hindu. “The Teesta project was successful and commercially viable. The electrical equipment (to generate electricity) was practically intact, so there were strong reasons to put it into service again, but with a more solid structure and an improved early alert system. ” He said there was no proposal to leave the project after the accident.
The cost factor
A pure concrete and concrete structure had its own inherent advantages, but the “cost” also played an important role, the person added. The new design incorporated a “worst scenario”, that is, the maximum possible rain in the upstream glacier lake, modeling by the Indian weather department, in the South Lhonak region for the next 100 years, which influenced modifications Additional downstream.
“To improve the safety of personnel working during project operations, Sul plans to transfer the control room of the dam to a higher elevation. In addition, Sul will implement an early warning system in the upper basin that will give enough time to move the workforce of the dam site and operate and safely open all the dams of the dam in case of a flood, ”says the Recommendation Report of the Expert Committee.
It is estimated that the additional costs of restoring the dam will be 4,189 million rupees. The cost of the project in 2017, when it was launched, was 13,965 million rupees.
“The underground power plant and electromechanical equipment could be restored to its original state in about 10 to 12 months. The water conduction system is not mostly affected by sudden flood, so, apart from the dam, most components can be restored within one year. As most components would be ready in a year, there are reasons to restore the dam and put the project into operation, ”said the project’s proponents in their report to the Evaluation Committee.
Published – January 27, 2025 10:24 pm ist
By
