Kallanai is an ancient dam built by Karikala of Chola dynasty in 150 CE. It is built across the Kaveri river flowing from Tiruchirapalli District to Thanjavur district, Tamil Nadu, India. The dam is located in Thanjavur district, 15 km from Tiruchirapalli and 45 km from Thanjavur. It is the fourth oldest water-diversion or water-regulator structure in the world and the oldest in India that is still in use. Because of its spectacular architecture, it is one of the prime tourist spots in Tamil Nadu.
Kallanai Dam with its floodgates open
Plaque bearing the dam's name
Engineering wonder of Karikalan's period
Fishing in the sluices, Kallanai dam, Tiruchirappalli
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions.
The Edersee Dam in Hesse, Germany
The Roman dam at Cornalvo in Spain has been in use for almost two millennia.
Remains of the Band-e Kaisar dam, built by the Romans in the 3rd century AD
An engraving of the Rideau Canal locks at Bytown
