Unexpected inflows to Srisailam, Nagarjunasagar benefits

Hyderabad: With sudden increase in inflows from Handri, Tungabhadra and Krishna rivers on Tuesday, Srisailam dam authorities said that they will take a decision on opening the floodgates on Wednesday morning. 

The dam authorities are confidant of matching the inflows with the outflows without letting waters out from the spillway gates so that the inflows could be utilised for generation of around 1,600 MW from both the power houses. 

Srisailam chief engineer C. Narayana Reddy said, “We will review the situation tonight as well as tomorrow morning. There were unexpected inflows from Handri rivulet (around 40,000 cusecs) and Sunkesula barrage on Tungabhadra (around 70,000 cusecs) in Kurnool district this morning due to heavy rains in catchment areas. Besides, we are also getting around one lakh cusecs from Jurala (Krishna river) which may go up to 1.50 lakh cusecs. All these inflows are contributing around two lakh cusecs to Srisailam dam, but we will have to see if the inflow pattern sustains or not.” 

Mr Narayana Reddy said if they are unable to match the inflows with outflows, they would have to operate the floodgates to release more waters to Nagarjunasagar dam downstream.

Whether the Srisailam dam authorities release waters through the power houses or from the floodgates, Nagarjunasagar dam will be the ultimate beneficiary. It can still accommodate around 160 tmc ft.

Presently, around 75,000 cusecs are being released from both the power houses to generate power (this water will reach Nagarjunasagar Dam). Besides releases to Pothireddypadu, Srisailam authorities are also diverting around 11,000 cusecs to Nippula Vagu rivulet from the escape channel of Banakacherla cross regulator that will fall in Kundu river that will in turn join Penna river at Adinimmayapalli in Kadapa district. 

“We need to supply 15 tmc ft of water to the Chennai drinking water supply scheme; we are now able to make releases through Pothireddypadu so that it will be picked up at Somasila and Kandaleru dams in Nellore district from where it will reach Chennai,” Mr Narayana Reddy said.

At 9 am on Tuesday, Jurala dam was getting only 64,000 cusecs and officials were operating power houses for release of inflows. However, within two hours, inflows went up to 78,000 cusecs and by 3 pm they touched 1.15 lakh cusecs forcing dam authorities to operate the spillway gates to release more waters to Srisailam.

Meanwhile, Krishna River Management Board in an unusual decision asked engineers-in-chief of both Telangana and Andhra Pradesh states to settle the water releases bilaterally. 

The Board washed its hands off from the various controversies arising out of water allocations and decided to leave the matter to both the states. 

The KRMB, in its letter addressed to both engineers-in-chief, said, “KRMB observed that both the states are releasing water through Srisailam project power houses from October 6 onwards, before the water release order was issued as requested by engineer-in-chief of Andhra Pradesh. In view of the above, both the engineers-in-chief are requested to bilaterally settle the releases through power houses, including waters already drawn to match outflows with the inflows considering the safety of Srisailam sam and to maintain the requisite level”.