Why is it in the News?

In a significant stride towards bolstering India's energy security, the state-owned Oil and Natural Gas Corporation (ONGC) has successfully unearthed two substantial natural gas reserves within the Mahanadi basin block in the Bay of Bengal.

About the Mahanadi River Basin:

• Ranked as the 8th largest river basin in the country, the Mahanadi River Basin boasts a substantial catchment area spanning 139,681.51 sq. km, representing approximately 4.28% of the total geographical area of India.
• Encompassing significant portions of Chhattisgarh and Odisha, along with smaller segments of Jharkhand, Maharashtra, and Madhya Pradesh, this basin stretches across diverse terrains and is surrounded by the Central India hills to the north, the Eastern Ghats to the south and east, and the Maikala range to the west.
• The basin's physiographic features are categorized into four regions:
  • The northern plateau
  • The Eastern Ghats
  • The coastal plain (a fertile delta area), and
  • The erosional plains of the central tableland.
• Notably, the basin receives about 90% of its rainfall during the monsoon season.
• Agriculture dominates the landscape, covering 54.27% of the total area, while water bodies occupy 4.45%. Predominant soil types include red and yellow soils.

Key Characteristics of the Mahanadi River:

• As one of the major east-flowing peninsular rivers in India, the Mahanadi River originates from the Sihawa range of hills in the Dhamtari district of Chhattisgarh.
• Water Potential: Second only to the Godavari River in terms of water potential among peninsular rivers, the Mahanadi River spans a total length of 851 km, with 357 km flowing through Chhattisgarh and 494 km through Odisha.
• Tributaries: The river is augmented by left bank tributaries including the Seonath, Hasdeo, Mand, and Ib, while the right bank receives contributions from the Ong, Tel, and Jonk.
• Hirakud Dam: An engineering marvel, the Hirakud Dam, recognized as the world's longest earthen dam at 26 km, is strategically located about 15 km from Sambalpur in Odisha, providing essential water management for the region.
• The Mahanadi River plays a crucial role in the hydrology of Chilika Lake, designated as a wetland of international importance under the Ramsar Convention.
• Approximately 61% of the lake's inland flow originates from the Mahanadi River system, mainly through its distributaries, Daya and Bhargabi.