HYDERABAD: Expressing concerns over the deterioration in the plunge pool area of the Srisailam dam, which poses a serious threat to the safety of the dam, Telangana Irrigation officials requested the National Dam Safety Authority (NDSA) to intervene and ensure the safety of the dam.
The State Committee on Dam Safety (SCDS) officials wrote a letter to the NDSA chairman to this effect on Wednesday.
“Constructed in 1981 across the Krishna river, this multipurpose dam is a critical asset that provides hydroelectric power (with installed capacity of 900 MW for Telangana and 770 MW for Andhra Pradesh), irrigation, and drinking water supply to vast regions of Andhra Pradesh and Telangana. Further, it also plays an essential role in flood control in both states apart from supplying drinking water to Chennai through the Telugu Ganga Project,” the Telangana officials said.
They said the recent inspections indicated that huge discharge during the 2009 floods (about 25 lakh cusecs against designed 14 lakh cusecs) resulted in significant scouring and formation of a large void in the plunge pool downstream of the dam’s spillway. Reports indicate that unpublished studies conducted by the National Institute of Oceanography, commissioned by the erstwhile Andhra Pradesh government, warn that if left unaddressed, the erosion poses a serious threat to the dam’s overall stability. The dam’s maximum height is 143.26 m from the deepest foundation level, officials said.
“In the event of a breach, the cascading effects would be catastrophic. A breach at Srisailam dam would rapidly release an enormous volume of water, potentially inundating downstream areas across Andhra Pradesh and Telangana. This could lead to extensive damage to power, irrigation infrastructure, water supplies and cause a severe humanitarian crisis for lakhs of residents in both states,” the letter stated.
The state irrigation officials requested the NDSA to depute an expert team to comprehensively assess the extent of damage in the plunge pool and review the current structural integrity of the dam. “Examine temporary remedial measures, including the filling of interlocking tetrapods in the plunge pool to enhance energy dissipation and prevent further scouring in the upcoming rainy season,” the officials added.
They also wanted the NDSA to develop a coordinated action plan that addresses both immediate temporary measures and long-term rehabilitation strategies to safeguard the dam.
Considering the cascading downstream risks, a breach at Srisailam dam could severely impact the safety of Nagarjunasagar dam, Pulichintala and Prakasam barrages. “Such an event would likely lead to extensive resource losses in irrigation, power generation, and drinking water supply systems across AP and Telangana, including Chennai water supply. Examine the above and urgently intervene to prevent further degradation and ensure the continued safe operation of this vital infrastructure, as well as to protect the lives and livelihoods of hundreds of thousands of people, including hydropower, irrigation, and drinking water sources,” the officials said in the letter.