|Nagarjuna Sagar Dam|
Nagarjuna Sagar Dam is a masonry dam built across Krishna River in Nagarjuna Sagar, Andhra Pradesh, India. It is the world's tallest masonry dam, at a height of 124 metres, and creates a reservoir holding up to 11, 472 million cubic metres.
It is one of the earliest irrigation and hydro-electric projects in India. The dam provides irrigation water to the Nalgonda District, Prakasam District, Khammam District, and Guntur District.
The Krishna River is a river of India that originates at Mahabaleswar in Maharashtra, passes through Sangli and meets the sea in the Bay of Bengal at Hamsaladeevi in Andhra Pradesh. The state of Andhra Pradesh was unable to effectively use the river until the mid 20th century, due to the absence of a reservoir which could store the water. River floods devastated the villages in the Krishna District while Nalgonda district and Guntur were unable to use the excess water.
The proposal to construct a dam to use the excess waters of the river was put forward by the British rulers in 1903. Siddeswaram and Pulichintala were identified as the suitable locations for the reservoirs. However, none of these proposals materialized. The perseverance and single minded determination of the Raja of Muktyala paved way for the construction of the dam.
Based on the reports submitted by the Khosla committee in 1952, the congress government formed under the leadership of Jawaharlal Nehru decided to construct reservoirs in drought hit areas under the first five year plan. The state governments were asked to submit a report on the possible locations for such project. After the formation of the Andhra Pradhesh state in 1953 and the submission of a report by the government, the foundation stone for the Nagarjuna Sagar dam was laid on 10 December 1955. It was named after the buddhist monk Nagarjuna.
 Project construction
The dam water was released by the then Prime Minister's daughter, Indira Gandhi in 1967. The consruction of the dam submerged an ancient Buddhist settlement, Nagarjunakonda, which was the capital of the Ikshvaku dynasty in the 1st and 2nd centuries, the successors of the Satavahanas in the Eastern Deccan. Excavations here had yielded 30 Buddhist monasteries, as well as art works and inscriptions of great historical importance. In advance of the reservoir's flooding, monuments were dug up and relocated. Some were moved to Nagarjuna's Hill, now an island in the middle of the reservoir. Others were moved to the mainland.
The project started in February 1956 but due to scarcity of funds modern equipment was not available. The project was constructed with stone instead of concrete. A cement factory was constructed near Macherla to meet the project requirement. A railway line was laid connecting the project location and the cement factory. Stones were supplied from the nearby Sunkesula quaries. Sand was supplied from Rayavaram stream and Halia river. The construction of the dam was completed by 1969. The dam came under full usage from 1972 after fitting the crest gates. Two canals - the left and right canals were constructed to supply water from this reservoir. Total expenditure on the project (including maintenance till 2005) is around 1300 crore rupees. The number of workers participating in the project varied from 45,000 to 70,000. Around 174 people died due to accidents during the construction.
 Effect of the project
The project benefited farmers in the districts of Guntur, Prakasam, Krishna, Nalgonda and Khammam. The right canal (a.k.a Jawahar canal) is 203 km long and irrigates 1.113 million acres (4,500 km²) of land. The left canal (a.k.a Lalbahadur Shastri canal) is 295 km long and irrigates 1.03 million acres (4,200 km²) of land. The project transformed the economy of above districts. 52 villages were submersed in water and 24000 people were affected. The relocation of the people was completed by 1967.
 Power Generation
The hydro electric plant has a power generation capacity of 815.6 MW with 8 units(1x110 MW+7x100.8 MW). First unit was commissioned on 7th March 1978 and 8th unit on 24th December, 1985. The right canal plant has a power generation capacity of 90 MW with 3 units of 30 MW each. The left canal plant has a power generation capacity of 60 MW with 2 units of 30 MW each.