Dams in Tamil Nadu have been erected mainly with the aim of providing sufficient water to the agricultural lands. They are also used for the generation of hydroelectric power. Some of the dam sites serve as major tourist attractions with several reservoirs acting as fish breeding centers. Most of the rivers flowing in the state of Tamil Nadu are evenly dammed in such a way that no district of the state runs short of the basic water requirements. There are 117 dams in Tamil Nadu, which contribute immensely in boosting the agricultural economy of the state. Some of the dams in Tamil Nadu are described below.

Mettur Dam
Mettur Dam is one of the most prominent dams in Tamil Nadu. This dam is located at a distance of about 30 km from Salem. It was constructed in the year 1934. Mettur Dam was built in a gorge, where the Kaveri River enters the plains. The dam has a height of about 65 meters and a length of about 1616 meters. It occupies an area of about 15,540 hectares. The maximum capacity of the dam is about 93.47 tmc ft. The dam irrigates about 1,310 square kilometers of agricultural land every year. This dam facilitates irrigation in about 271,000 acres of farm land in the districts of Thanjavur, Salem and Tiruchirappali. Mettur Hydro Electrical Power Project is a big project associated with Mettur Dam. The installed capacity of the dam for hydro-power generation is about 32 megawatt.

Vaigai Dam
Vaigai Dam has been constructed across Vaigai River, close to Andipatti in the district of Theni in Tamil Nadu. The dam was mainly constructed to serve the purpose of irrigation in the districts of Dindigul and Madurai and cater to the drinking water requirements in Andipatti and Madurai.

Amaravathi Dam
Amaravathi Dam has been constructed on Amaravati River. It is situated at Amaravathinagar in Tirupur district of Tamil Nadu. It was opened in the year 1957. The reason behind the construction of the dam was irrigation and flood control. It is also utilized for the generation of electricity. The reservoir and catchment basin of the dam provide shelter to mugger crocodiles and are famous for them.

Mukkadal Dam
Mukkadal Dam has been constructed across Vambaru River. It is located about 10 km (6.2 mi) from town of Nagercoil in Tamil Nadu. The dam is made up of clay and granite stones. It was constructed in the year 1945. Sree Chithira Thirunal Balarama Varma, a former king of Travancore is credited with the establishment of this dam. The dam site is considered to be a scenic place, favorable for picnics.

Aliyar Dam
Aliyar Dam was built between 1959 and 1969. It is located at the foothills of Valparai in the Anamalai Range of Western Ghats. This dam was built chiefly to cater to the irrigation requirements of the nearby areas. Presently, the discharges from the dam are being let down through canals or slucies. They are the Vettaikaranpudur Canal, the Pollachi Canal and river sluices.

Bhavanisagar Dam
Bhavanisagar Dam has been constructed across Bhavani River. The dam is situated 16 km west of Sathyamangalam and 36 km north-east of Mettupalayam in the district of Erode in Tamil Nadu.

Other Dams in Tamil Nadu
Some of the other dams in Tamil Nadu are mentioned below: