Srisailam Dam
The Srisailam Dam is constructed across the Krishna River in Nandyal district, Andhra Pradesh and Nagarkurnool district, Telangana near Srisailam temple town and is the 2nd largest capacity working hydroelectric station in India.
| Srisailam Dam | |
|---|---|
Location of Srisailam Dam in Andhra Pradesh | |
| Location | Sri Sailam, Nandyal district, Andhra Pradesh, India Domalapenta, Nagarkurnool district, Telangana, India |
| Coordinates | 16°05′13″N 78°53′50″E |
| Purpose | Hydroelectric, Irrigation & Water supply |
| Construction began | 1960 |
| Opening date | 1981 |
| Construction cost | ₹10 billion |
| Owner(s) | Government of Andhra Pradesh |
| Dam and spillways | |
| Type of dam | Gravity & Masonry dam |
| Impounds | Krishna River |
| Height | 145.10 m (476 ft) |
| Length | 512 m (1,680 ft) |
| Spillway capacity | 38369 cumecs |
| Reservoir | |
| Creates | Srisailam Reservoir (Neelam Sanjeevareddy Sagar) |
| Total capacity | 216 Tmcft |
| Catchment area | 206,040 km2 (79,550 sq mi) |
| Surface area | 616 km2 (238 sq mi) |
| Power Station | |
| Operator(s) | APGENCO(right bank) and TSGENCO(left bank) |
| Turbines | 6 × 150 MW (200,000 hp) reversible Francis-type (left bank) 7 × 110 MW (150,000 hp) Francis type (right bank) |
| Installed capacity | 1,670 MW (2,240,000 hp) |
The dam was constructed in a deep gorge in the Nallamala Hills in between Nandyal and Nagarkurnool 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. Its gross storage capacity is 6.116 cubic km (216 tmc ft). The minimum draw-down level (MDDL) of the reservoir is at 705 feet (215 m) MSL from its river sluice gates and corresponding dead storage is 3.42 Tmcft. The left bank underground power station houses 6 × 150 megawatts (200,000 hp) reversible Francis-pump turbines for pumped-storage operation (each Turbine can pump 200 cumecs) and the right bank semi-underground 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 into 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 hydropower stations. Tail pond weir was completed during the year 2017 and pumping mode operation is being done even when the downstream Nagarjuna Sagar reservoir water level is below 531.5 feet (162 m) MSL. The tail pond has nearly 1 tmcft live storage capacity.