The Mahanadi River is a major river in East Central India. It drains an area of around and has a total length of . Mahanadi is also known for the Hirakud Dam. The river flows through the states of Chhattisgarh and Odisha and before finally ending in the Bay of Bengal. Etymology The word Mahanadi is a compound of the Sanskrit words maha ("great") and nadi ("river"). In different era, this river was known by several names, such as: Ancient era – Kanaknandini Dvapara Yuga – Chitrotpala (Similar name in Matsya Purana) Treta Yuga – Nilotpala (Similar name in vayu Purana) Mahabharata era – Mahanad Kali Yuga – Mahanadi or Mahashweta Course Source and Upper Course Like many other seasonal Indian rivers, the Mahanadi too is a combination of many mountain streams and thus its precise source is impossible to pinpoint. However its farthest headwaters lie from Pharsiya village in Nagri Sihawa above sea level about 11 km, in a dense patch of forest, south of Sihawa town in Dhamtari district of Chhattisgarh. The hills here are an extension of the Eastern Ghats and are a source of many other streams which then go on to join the Mahanadi. For the first of its course, the Mahanadi flows in a northerly direction and drains the Raipur district and touches eastern portions of Raipur city. It is a rather narrow river at this stage and the total width of its valley does not exceed 500–600 metres. Middle course After being joined by the Shivnath, the river flows in an easterly direction through the remaining part of its journey. It is joined by the Jonk and Hasdeo rivers here before entering into Odisha after covering about half of its total length. Near the city of Sambalpur, it is dammed by the longest earthen dam in the world, the Hirakud Dam. A composite structure of the earth, concrete and masonry, the dam measures including the Dykes. It spans two hills; the Lamdungri on the left and the Chandili Dunguri on the right. It also forms the biggest artificial lake in Asia, with a reservoir holding at full capacity, with a shoreline of over . After the formation of Chhattisgarh State, the major portion of Mahanadi basin now lies in Chhattisgarh. Presently, only basin area of Hasdeo River in Anuppur District lies in Madhya Pradesh. Before the construction of the dam in 1953, the