Kurnool: Structural stability of Srisailam dam has become a cause of concern. After a prolonged delay, Scientists from the National Institute of Oceanography, Goa, has begun a videographic survey of plunge pool work from Wednesday.
Executive engineer M. Samba Siva Reddy said that with the help of videos, the depth of the foundation and formation of any cavities could be ascertained. He said that plunge pool was formed in an extent of 400 metres, out of a total length of 594.36 metres (1,950 ft). The corrosion impact and its propensity will be spread to other areas of the dam which is being studied to take remedial measures.
Srisailam dam, which is a designated dam of national importance, was reviewed by National Committee on Dam Safety (NCDS) on February 12, 2019 in Bhubaneswar. The minutes of the meeting recorded indicate that there is an urgent requirement to focus on the status of flood review of Srisailam dam, to increase the spillway capacity.
According to the minutes of the meeting, chief engineer of AP , informed that the PMF studies (73,852.3 cusecs) of the dam were carried out by a consultant along with departmental staff. The issues were also referred to a dam safety Panel of Experts (PoE) under the chairmanship of A.B. Pandya, former chairman of CWC.
As suggested by the PoE, regarding the erosion of a plunge pool located opposite to 4th to 16th blocks on the natural river course, the bathymetric survey work entrusted to the NIO, Visakhapatnam was completed and the final report is awaited.
He further stated that for the eroded portion of the apron, the projection measures at the toe of the dam opposite to block numbers 6 and 8 at downstream of spillway bucket is under progress (30% completed).
The committee was informed that the work of preparation of emergency action plan and dam break analysis was entrusted to NIH, Roorkee. The studies were not done. Along with other remarks, reports were communicated to the NIH, Roorkee for a report.
The Srisailam dam project was built during 1963-1982 at a cost of `500 crore. Water discharged from the dam crest gates jump into the bucket area and raises to a height of 200 ft and lands at a distance of 300 metres.
Under the pressure from the water, the 200-ft ditch was formed.
Chief engineer Narayana Reddy said that the NIA team would carry out their work for a period of 10 days, he said.
