Why in News?
In mid‑October 2025, incessant rain over the Varusanadu hills and inflows from the Mullaperiyar dam caused the Vaigai dam in Tamil Nadu to rise rapidly to more than 66 feet, prompting flood warnings for Theni, Dindigul, Madurai, Sivagangai and Ramanathapuram districts. The episode underscored the dam’s importance for irrigation, drinking water and flood control in the region and spurred discussions about its history and capacity.
Background
The Vaigai dam is a gravity dam built across the Vaigai River near Andipatti in Theni district. It was inaugurated on 21 January 1959 by then Chief Minister K. Kamaraj. Standing 33.8 metres (about 111 feet) high and 3,560 metres long, the dam can store up to 6.14 thousand million cubic feet (tmc ft) of water at its full reservoir level of 71 feet. It is one of the few large dams in India not situated between mountains; its stability depends on concrete strength and careful maintenance. The dam is managed by the Tamil Nadu Water Resources Department and supplies water through an extensive canal system.
Key roles of the dam
- Irrigation lifeline: The reservoir waters irrigate fields across six districts – Theni, Dindigul, Madurai, Sivagangai, Virudhunagar and Ramanathapuram – supporting paddy, sugarcane, pulses and horticultural crops.
- Drinking water supply: Cities such as Madurai, Theni and Ramanathapuram draw drinking water from the Vaigai. During droughts, controlled releases from the dam ensure water security for urban populations.
- Hydropower generation: Downstream of the dam is the Vaigai hydroelectric power plant, commissioned in 1990, which houses two turbines of 3 MW each. Though small, it supplies renewable electricity to the regional grid.
- Flood moderation: By regulating inflows from tributaries such as the Moola Vaigai, Kottagudi and Manjalar streams, the dam reduces flood risk downstream. Controlled releases are essential during heavy rainfall to maintain structural safety and protect communities.
- Recreation and research: A park with gardens and a musical fountain is maintained on either side of the dam, attracting visitors. The Tamil Nadu Agricultural University operates a research station near the dam to study crops suited to the region.
Recent developments
- Flood warnings: On 19 October 2025 the Water Resources Department issued first‑stage flood alerts after the storage crossed 66 feet. Continuous monitoring and regulated outflows helped avert downstream flooding.
- Water release to canals: Farmer groups urged the government to release water through the 58‑canal system to recharge tanks and wells. Authorities subsequently approved release of over 1,800 million cubic feet for irrigation.
- Dam rehabilitation: The Vaigai dam is part of the Dam Rehabilitation and Improvement Project (DRIP) and is slated for upgrades to its spillway gates, instrumentation and emergency preparedness.
Sources: Oneindia; Wikipedia; The New Indian Express