The dam was constructed in a deep gorge in the Nallamala Hills in between Mahabubnagar and Kurnool districts, 300 m (980 ft) above sea level. It is 512 m (1,680 ft) long, 145 metres (476 ft) maximum height and has 12 radial crest gates. It has a reservoir of 616 square kilometres (238 sq mi). Project has an estimated live capacity to hold 178.74 Tmcft at its full reservoir level of 885 feet (270 m) MSL. The left bank underground power station houses 6 × 150 megawatts (200,000 hp) reversible Francis-pump turbines for pumped-storage operation and the right bank semi under ground power station houses 7 × 110 megawatts (150,000 hp) Francis-turbine generators.
Tail pond dam /weir located 14 km downstream of Srisailam dam is under advanced stage of construction to hold the water released by the hydro turbines and later pump back in to the Srisailam reservoir by operating the turbines in pump mode. The weir portion got breached in November 2015 unable to withstand the normal water release from the hydro power stations.
The Srisailam project began in 1960, initially as a power project. After several delays, the main dam was finally completed twenty years later in 1980 July 26. In the meantime the project was converted into a multipurpose facility with a generating capacity of 770 megawatts (1,030,000 hp) by its second stage which was completed in 1987. The dam is to provide water for an estimated 2,000 square kilometres (770 sq mi). Under the right bank branch canal 790 square kilometres (310 sq mi) in Kurnool and Kadapa districts will have assured irrigation. From the initial modest estimate of ₹384.7 million for a power project the total cost of the multipurpose project was estimated to cross ₹10 billion in its enlarged form. The dam has alone cost ₹4.04 billion together with the installation of four generating sets of 110 MW each. The right bank branch canal is estimated to cost ₹4.49 billion and the initial investment of ₹1.4 billion has been provided by the World Bank. The projected cost-benefit ratio of the project has been worked out at 1:1.91 at 10% interest on capital outlay.. On 2 October 2009, Srisailam dam experienced a record inflow which threatened the dam.
At present the initial inflows into Srisailam reservoir are stored excessively without using for power generation. The flood water fills the remaining empty Srisailam reservoir quickly and most of the flood water overflows into downstream Nagarjunasagar reservoir without being used for power generation. The endeavor shall be to fill the Nagarjunasagar reservoir fully with the uniform water released through the power generating units.