When the crest gates on the spillway of Srisailam reservoir, a joint multi-purpose project of Telangana and Andhra Pradesh, were operated around the intervening midnight of Saturday-Sunday, a sort of history was created in the annals of the project as they were lifted for the record sixth time during a monsoon period, after the dam attained its full capacity.
The engineers monitoring the flood to Srisailam reservoir lifted one crest gate of the project around midnight for a height of 10 feet initially to discharge over 28,000 cusecs of water. As the inflows were in the range of about 1.51 lakh cusecs, the authorities lifted the second gate around 12.30 a.m., third around 6 a.m. and fourth gate around 10.30 a.m., all for 10 feet height each, to increase the flood discharge from the spillway to over 1.12 lakh cusecs as the water storage reached the dam’s full capacity of 215.81 tmc ft and the full reservoir level of 885 feet.
In addition, over 69,000 cusecs of water was also being let into the river after power generation in the right and left bank power houses operated by AP and Telangana, respectively.
Irrigation authorities stated that the current water year, June-May, is proving to be the among the best during the last couple of decades, the fourth-best in terms of volume of inflows into Srisailam as it has received over 1,375 tmc ft of water till 6 a.m. on Sunday from June 1 this year. “The current water year is different from 2005-06 to 2007-08, the top three years in terms of volume of flood received into Srisailam, as the number of flood days are more and are spread across August, September and October,” a flood monitoring engineer explained.
Heavy inflows into the reservoir also helped in high hydel generation at Srisailam, over 1,818 million units (MU) till October 12 this year (from April 1) including over 1,080 MU by Telangana and the rest by AP. For Telangana, the contribution of Srisailam is higher in term of power generation as the hydel generation at the left bank power house constitutes nearly 44% of the total 2,486 MU of hydel generation achieved so far this year (till October 12), a Genco official told The Hindu .
Meanwhile, over 1.5 lakh cusecs of flood was also being discharged from the 10 crest gates of Nagarjunasagar project as at 9 p.m. on Sunday by lifting them for 10 feet height each.
Another 32,400 cusecs was also being let into the river course after power generation. In the Godavari Basin, Sriramsagar was also appraoching 82 tmc ft against its capacity of 90.3 tmc ft on Sunday evening.