M. Malleswara Rao

HYDERABAD: Irrigation authorities on Friday commenced works on strengthening the concrete cover of the river-bed in front of Srisailam dam with another concrete layer to prevent possible scouring when the crest gates are opened during floods.

Concrete layer

Any scouring of the river-bed at this spot will endanger the dam.

As a fresh concrete layer will prolong the dam’s life span, the government wanted to take up this crucial work during the last three successive years but postponed it every time due to floods.

Ample scope exists now to execute the work as the water level in the reservoir has come down to 815 ft. Also, the spot where the concrete layer has to be provided, is visible as it lies two below the water in front of the dam. Stagnant water at this spot is called “plunge pool” which is always maintained at some depth to minimise the impact of the waterfall on the river-bed.

On Friday, workers began cleaning the existing concrete cover by removing debris, loose boulders and fungus.

Y. Abdul Basheer, chief engineer, Srisailam, says that the work had been taken up at a cost of Rs 1.7 crore and would be completed in a month to make the plunge-pool ready before the flood season. The AP Genco stopped operation of the powerhouse on the right bank of the dam. He said all the 12 radial crest-gates of the dam were in an excellent condition.

Talking to The Hindu, he said there was, however, no problem in operating the left bank powerhouse because the water released by this powerhouse would join the river one km downstream of the dam. The powerhouse is likely to begin operation within a week after completion of the repairs and make available 900 MW capacity to the grid.