Bansagar or Ban Sagar is a multipurpose river valley project, constructed on Son River. The dam is located in Ganga Basin in Madhya Pradesh, India. The objective to build this dam was to enhance both irrigation and hydroelectric power generation. The Bansagar Dam is constructed at village Deolond in Shahdol district. The dam is located at a distance of 51.4 km from Rewa.

The project has been named as "Bansagar" after the renowned Sanskrit scholar of 7th century - Bana Bhatt. Bansagar Dam co ordinates the Latitude of 24-11-30 N and Longitude 81-17-15 E. The project was initially visualized in 1956 as the "Dimba Project" by Central Water Commission New Delhi. It was planned to build at the confluence of Sone and Banas River near Shikarganj town 30 km down the present site. However, later the dam site was shifted to the present site at Deolond.

The State Governments of Madhya Pradesh, Uttar Pradesh and Bihar decided upon an agreement in 1973 for the construction of the Dam, according to which States decided to share the expenditure in the ratio of 2:1:1. 4-maf of water has to be shared by the states in the same ratio. The construction work of the dam was started in year 1978 at the predetermined cost of Rs. 91.31 crores. The final anticipated cost in 1998 was Rs. 1054.96 crores.

The primary benefit of the Bansagar Dam is related to the irrigational purposes. The water sharing from Bansagar Dam is as under Madhya Pradesh, Uttar Pradesh and Bihar.

Bansagar dam provides irrigation facility over an area of 2,490 km² in Madhya Pradesh, 1,500 km² and in Uttar Pradesh and 940 km² in Bihar.

The Bansagar Dam provides power generation of 425 MW in Madhya Pradesh. The Bansagar Canal Project started in 1978 and completed in 2008. The Canal Systems, which are under construction to utilize water from the Bansagar Reservoir, shall be started shortly.