Discharge of flood from the spillway of Nagarjunasagar, which was the only project in the Krishna and Godavari Basins in Telangana yet to release surplus flood from the crest gates this season, commenced early on Thursday with the project authorities performing pooja and switching on motors to lift 10 gates for 5 feet height each around 5.30 a.m.
Initially, the flood discharge from the spillway was about 77,750 cusecs when the reservoir storage reached 304.9 tmcft (586.9 ft) against its capacity of 312 tmcft (590 ft full reservoir level). It was gradually increased to about 1.46 lakh cusecs by lifting the gates for another 5 ft height each (total of 10 ft each) around 9 am and to over 2.33 lakh cusecs by lifting another 6 gates around 11 a.m.
By noon, 20 gates were lifted for 10 ft height each to increase the spillway discharge to over 2.92 lakh cusecs, and around 2 p.m. six more gates were also lifted for 10 ft height each to take the total gates lifted to 26 increasing the discharge to 3.8 lakh cusecs. At 9 p.m., inflow into the project was being recorded at over 4.24 lakh cusecs and the same quantum as total discharge including with power generation and release to canals, by maintaining the storage at 304 tmcft.
In 2021, the spillway gates were lifted on August 1, in 2020 and 2019 they were lifted on August 12 and in 2018 the gates were lifted on August 20. In the downstream Puilichintala, the Andhra Pradesh authorities took up spillway discharge on Wednesday night itself expecting heavy release of flood from Nagarjunasagar.
In the upstream of Nagarjunsagar, Srisailam was getting a flood of 4.54 lakh cusecs from Krishna and Tungabhadra and discharge of flood from the spillway was nearly 3.77 lakh cusecs from 10 gates lifted for 15 ft height each. Another 61,500 cusecs was being let out with power generation by Andhra Pradesh and Telangana and another 18,000 cusecs drawals by Pothireddypadu, Handri-Neeva and Kalwakurthy systems.
With the Central Water Commission (CWC) indicating further rise in inflow to Almatti and Narayanpur dams following very heavy to extremely heavy rains continuing in the Upper Krishna Basin, the spillway discharge of flood at Jurala was increased to 2.45 lakh cusecs from 38 crest gates on Thursday night.
Steady flood
In the Godavari Basin downstream of Yellampally, Medigadda was discharging 9.88 lakh cusecs flood with rising trend forecast as Wardha and Wainganga rivers were flowing in extreme and severe level in the upstream Maharashtra. The flood is expected to reach Medigadda from Pranahitha from Friday afternoon. Meanwhile, the flood level in Godavari at Bhadrachalam was nearing 52.5 ft, little short of the third warning level of 53 feet.
