Nizam Sagar, Water reservoir in Telangana, India

Nizam Sagar is a dam across the Manjira River that holds back a large body of water for agricultural use. The reservoir supplies irrigation to farming areas across the region and serves as a water source for nearby settlements.

Nizam Sagar was taken up in 1923 by Mir Osman Ali Khan, the seventh Nizam of Hyderabad State, and completed in 1931; over 40 villages were emptied to make way for the reservoir. It was the second irrigation scheme on the Manjira and the largest in the then Hyderabad State, planned to irrigate 275,000 acres in Banswada, Bodhan, Nizamabad and Armoor taluks. After the 1956 reorganisation of states the Manjira basin was split among Maharashtra, Karnataka and Telangana, and silt surveys in 1973 showed storage far below the original design.

The dam is named after the Nizam of Hyderabad, Mir Osman Ali Khan, who built it in 1923. Local people hold that everyone should visit the place at least once in their life. The reservoir's stored water irrigates the command area of Banswada, Bodhan, Nizamabad and Armoor taluks.

The dam lies between Achampet and Banjepally villages in Kamareddy district, about 144 km north-west of Hyderabad, at roughly 18°10' N, 76°56' E. A 14-foot-wide road runs along the crest, so the reservoir is crossed on foot or by vehicle rather than toured by boat. The Manjira is a tributary of the Godavari, and inflows vary greatly between years.

The dam's storage capacity fell from 29.7 TMC to 11.8 TMC by 1973 as silt built up faster than designed. The full reservoir level was then raised from +1,400.50 ft to +1,405.00 ft, giving 17.80 TMC at the new level.