The story so far: Water from the Mettur Dam in Salem district of Tamil Nadu is released on June 12 every year to facilitate timely water for the rice crops in the delta districts.Water from this historical reservoir is the lifeline for many districts. With poor monsoon, the release has been delayed this year and Chief Minister C. Joseph Vijay will open water from dam on Tuesday (September 1, 2026).With the water level at nearly 90 feet, it will be released for about 45 days, which is critical for the paddy crop.Ground Zero: A dry spell along the Cauvery History of Mettur DamConstruction of Mettur dam began in 1925 and was completed in 1934, involving 17,000 workers. Residents of Nayambadi and nearby villages were evacuated then to facilitate the construction work. Even now, when the water level recedes, the old Christian Church of Nayambadi and the Nandhi of the Jalagandeeswarar temple are visible.The dam was constructed across the Cauvery to manage water supply for irrigation and hydroelectric power generation. The idea was conceived about a century ago by Sir Arthur Cotton, the dam was designed by Colonel W. M. Ellis, and the construction was carried out under the supervision of an Irish engineer Vincent Hart. The public park at the dam is named after Mr. Ellis.The funds were provided from the taxes collected in the Madras Presidency. The Board of Revenue was headed by Sir C.P. Ramaswamy Iyer, who initiated the building of the dam.The maximum height and width of the dam are 214 feet and 171 feet, respectively. And, its total length is 1,700m. The maximum water level of the dam is 120 ft (37 m) and the maximum capacity is 93.47 tmcft. Its reservoir area is 42.5 sq km.The dam receives inflows from its own catchment area, and Kabini and Krishna Raja Sagar (KRS) Dams, located in Karnataka.How many districts benefit from the Mettur Dam water?About 16.05 lakh acres of agricultural land in 12 districts, including Tiruchi, Thanjavur, Tiruvarur, Cuddalore, Nagapattinam, Erode, Pudukkottai, Ariyalur, Permbalur, Karur, Mayiladuthurai and Namakkal, benefit when water is released from Mettur Dam.The scheduled date for the opening of water is June 12 and the shutters are closed on January 28 every year with water available to these districts for 230 days annually. It is estimated that a total of 330 TMC is required for irrigation. For canal irrigation, water is discharged from the dam on August 1 every year for 137 days. This benefits nearly 45,000 acres in Salem, Namakkal, and Erode districts.In the 93-year history of the dam, water was discharged for delta irrigation 20 times on its scheduled date, June 12. On 11 occasions, water was released before June 12 and for 61 years water was discharged after June 12.Water discharge for canal irrigation began in 1955 and in the past 71 years, water was released 62 times. This included 35 years when water was released on the scheduled date of August 1, 14 times before August 1, and for 13 times, after August 1.What is the solution for the farmers?C. Varadharaj, president of the Tamil Maanila Congress (Mooppanar) farmers wing, pointed out that desilting of Mettur dam is a necessity. Farmers in delta region have dug borewells as they need water for irrigation. The government should ensure uninterrupted three-phase power supply for these farm lands to save the Kuruvai crops.What is the Mettur Surplus Water Scheme?Former Chief Minister Edappadi K. Palaniswami laid the foundation for the ₹565 crore Cauvery surplus water scheme on April 2020 aiming to fill the lakes and tanks in the Mettur, Omalur, Edappadi, and Sankari Assembly constituencies using surplus water from the dam.When the water level reaches 120 feet, the surplus water can be pumped to the main pumping station at Thippampatti through a lift irrigation system. From Thippampatti pumping station, it will be sent to lakes and tanks through pumping stations in Vellalapuram, Nangavalli, and Kannantheri. Mr. Palaniswami inaugurated the first phase of the scheme on February 26, 2021, and surplus water was pumped to four lakes.The DMK that came to power in 2021 alleged that the AIADMK government had started the scheme in a rush and had not acquire land for the project. It allocated ₹108 crore for the project in 2023 and works were expedited. In 2025, surplus water was pumped to 60 lakes. The project requires ₹115 crore more to pump water to all the lakes and tanks in the four constituencies.