Stanley Reservoir (also known as Mettur dam) is one of largest fishing reservoirs in South India. Its main source of water is the River Kaveri (Cauvery). Three minor tributaries – Palar, Chennar and Thoppar – enter the Kaveri on her course above Stanley Reservoir. The water is retained by the Mettur Dam, Tamil Nadu. Its total capacity is more than 93,470,000,000 cubic feet (93.47 Tmcft).(2,146,071 acre ft)
The Stanley Reservoir is one of the largest of its kind in India. It was completed in 1934. The creation of the reservoir caused the submersion of two villages, all of whose inhabitants were relocated to Mettur.
The total length of the dam is 1700 meters. The Mettur hydro electric power project is also quite large. The dam, the park, the major hydroelectric power stations and hills on all sides make Mettur a tourist attraction. It is named after Lieutenant Colonel Sir George Frederick Stanley GCSI GCIE CMG, He served the Governor of Madras from 1929 to 1934 and as Acting Viceroy of India in 1934.