ANANTAPUR: Srisailam reservoir, a major source of irrigation and power generation for Rayalaseema and Telangana, faces a threat to its safety due to excess inflows – more than the storage capacity.
The Pandya Committee has stressed the need to have measures in place for safety of the dam because the existing spillway was unable to check heavy floods. The flood capacity of Srisailam dam needs to be reviewed in the light of the unprecedented floods from Krishna river.
The chairman of the Central Water Commission (CWC) and the Pandya committee recommendations stress the need for timely action -- either construction of another spillway or increasing the height of the dam along with diversion of flood waters through left and right banks of the dam.
The Pandya committee was appointed in 2020 and it conducted the study on Srisailam reservoir last year. It recently submitted a report with recommendations to improve the safety of the dam.
The committee recommendations based on the study of the 1000 years of flows noted that the existing spillway capacity was 13.20 lakh cusecs. This, it said, could be raised to 14.55 lakh during emergency situations.
"But, the dam received 25.5 lakh cusecs in 2009 and 14.80 lakh cusecs were released when the dam capacity reached to 890ft. The dam can receive even 26.5 lakh cusecs if heavy floods occur in upstream parts of Srisailam," the committee stated.
In 2021, the maximum flood flow was about 17.88 lakh cusecs. The Pandya committee conducted a detailed study by splitting the Krishna basin into 256 sub divisions.
The plunge pool at the bottom with a deep pit is a cause of concern vis-à-vis the safety of the dam. The Pandya committee sought immediate action to rectify the plunge pool, which is peculiar for Srisailam because of the flow to a depth from the gates.
In addition, additional spillway about 5km away from upstream parts of the dam is proposed to avoid any burden on the main gates.
Another recommendation was the diversion of floodwaters through Pothireddypadu Head Regulator towards Chennai drinking water project and also other irrigation projects of Srisailam.
The Pandya committee also advised the authorities to make use of the technology with IMD to know of the likely flood levels and release water without affecting the structure of the reservoir.
