Indira Sagar Dam

Indira Sagar Dam is the second-largest reservoir in India by water capacity (12.22 cubic km, behind only Sardar Sarovar's parent reservoir Bargi Dam) and the second-largest dam on the Narmada river. Located at Punasa village in Khandwa district, Madhya Pradesh, the dam was completed in 2005 — 13 years after construction began in 1992.

The 92 m concrete gravity dam is part of the integrated Narmada Valley Development Project (NVDP), serving as the upstream reservoir for the downstream Sardar Sarovar project. Indira Sagar's primary purposes are: 1,000 MW hydropower generation (8 × 125 MW units), irrigation of 1.23 lakh hectares in MP via the Indira Sagar Canal Project, and downstream regulation for Sardar Sarovar.

Narmada Hydroelectric Development Corporation (NHDC) executed the project — a 50:50 joint venture between NHPC (national hydropower utility) and Madhya Pradesh State Electricity Board. HCC and L&T shared the civil construction.

Foundation works were challenging due to a complex geology — the dam straddles a transition zone between basalt (Deccan Trap) and Vindhyan sandstone, requiring asymmetric foundation grouting curtains on each side. The reservoir submerged 254 villages and displaced 50,000 people — the project endured prolonged Narmada Bachao Andolan opposition before final clearance.

The dam plays a critical role in regulated water release to Sardar Sarovar downstream — without Indira Sagar's storage buffer, Sardar Sarovar's irrigation reliability would drop significantly during dry seasons.