The six-and-a-half-decade-old Kaddam Narayana Reddy project survived another scare and test of the time on Thursday, the second year in a row, as it withstood over 4 lakh cusecs flood that was reaching it for about 10 hours, in spite of its effective discharge capacity of 2.43 lakh cusecs through 14 out of 18 spillway gates.
Four other spillway gates could not be operated (lifted) by the project engineers due to a “mechanical snag”. As a result, some quantity of water passed over the closed spillway gates’ head for about six hours forcing the authorities to vacate people living in 12 villages downstream on warfooting as they had no answer to allow higher discharge of flood from the spillway to lessen threat to the dam.
Construction of the project taken up in 1949 was completed in 1958, but in August that year the dam suffered a breach as it received 5.19 lakh cusecs flood against the designed discharge of 2.5 lakh cusecs forcing the expansion of the spillway to discharge 3.82 lakh cusecs. On July 13 last year, the engineers did not operate one gate due to a mechanical snag as the flood to dam was reported at about 5 lakh cusecs. On Thursday too the flood was put at over 5 lakh cusecs, unofficially.
“We have taken up maintenance of the crest gates and repaired the one with mechanical snag in the off-flood season and operated all 18 gates as part of our drill before the commencement of flood season this year. However, on July 21, a mechanical snag hit six gates during their operation to release about 1.75 lakh cusecs flood. Later that day, we succeeded in lifting three more gates. On Thursday, we faced a similar problem with four gates, but again we were able to operate one more gate,” a project engineer explained preferring anonymity.
The project authorities said the flood which commenced in the wee hours started receding in the afternoon and by 5 p.m. it came down to 1.52 lakh cusecs and over 2.4 lakh cusecs was being let out from the 15 spillway gates.
Against the maximum height of the dam with water at full reservoir level at 700 feet, the flood that was reaching the project beyond its effective discharge capacity crossed 702 feet on Thursday. The maximum height of the dam at the crest is 713.4 feet and the maximum height of earthen dam on the sides of the spillway is 716.7 feet.
Minister for Endowments and Law A. Indrakaran Reddy, local MLA A. Rekha Naik and district authorities rushed to the project site in the morning to assess the flood situation and to infuse confidence among the project staff. As the flood water was passing over the head of spillway gates that could not be lifted, the Minister said it was only in the hands of the almighty to reduce the flood and lessen the possibility of threat to the project.
