The height of the spillway gates has recently been increased by 1.5m using steel flaps. However, the additional storage made available by the increase cannot be used without the seismic strengthening of the spillway.
The dam has been strengthened after the December 1967 earthquake and was re-strengthened following the earthquake of September 1993.
Stages 1 to 4 of the Koyna dam have the potential to develop 1920MW.
