Drainage System of India: Himalayan and Peninsular Rivers, Patterns, Lakes and Odisha Rivers

These drainage system of India notes for OPSC/UPSC cover drainage patterns, the Himalayan and Peninsular river systems, tributaries, deltas, lakes, waterfalls and projects, with a full section on the rivers of Odisha. For OAS prelims the chapter gives steady fact questions on sources, tributaries, confluences and river-city pairs, and for mains it supports answers on floods, interstate water disputes, river linking and river pollution.

Drainage Patterns: Types and Examples

Drainage is the flow of water through well-defined channels, and a drainage system is the network of such channels in a basin. The pattern depends on slope, geological structure, rock resistance and the volume and velocity of water.

Special Drainage Terms

• Antecedent drainage: rivers older than the mountain, which cut gorges as it rose (Indus, Sutlej, Brahmaputra).
• Superimposed drainage: a pattern laid on one rock structure that persists after cutting down into a different structure beneath.
• Rift-valley drainage: Narmada, Tapi and Damodar.
• Inland drainage: rivers that do not reach the sea, such as the Luni of Rajasthan, which turns saline in its lower reach.

Himalayan and Peninsular Drainage Compared

Himalayan River Systems

Indus River System

The Indus rises near Bokhar Chu glacier in Tibet, near Mount Kailash and Lake Mansarovar, where it is called Singi Khamban, the lion’s mouth. It enters India in Ladakh and flows only through the Leh district in India before passing into Pakistan. The Zanskar and Shyok are its Ladakh tributaries, and the Punjab rivers join it lower down.

From north to south the Punjab rivers run Jhelum, Chenab, Ravi, Beas, Sutlej. The doabs between them are Bist (Beas–Sutlej), Bari (Beas–Ravi), Rachna (Ravi–Chenab) and Chaj (Chenab–Jhelum).

Ganga River System

The Ganga is formed at Devprayag where the Bhagirathi (from Gaumukh, Gangotri glacier) meets the Alaknanda. It enters the plains at Haridwar and flows through Uttarakhand, Uttar Pradesh, Bihar, Jharkhand and West Bengal before entering Bangladesh as the Padma. It reaches the Bay of Bengal near Sagar Island and forms the Sundarbans delta jointly with the Brahmaputra. The Ganga (about 2,525 km) is the longest river within India and was declared the national river in 2008.

• Yamuna tributaries: Chambal, Sindh, Betwa and Ken from the plateau side, west to east. The Ramganga is not a Yamuna tributary.
• Chambal: rises near Mhow; famous for deep ravines; Kota barrage and Rana Pratap Sagar.
• Sone: a plateau river joining the Ganga from the south near Patna; North Koel is a tributary of the Sone.
• Kosi: the sorrow of Bihar, which shifts its course widely; major shift in 2008.
• Damodar: rises on the Chota Nagpur plateau and joins the Hooghly; once the sorrow of Bengal; Damodar Valley Corporation was set up in 1948.

Brahmaputra River System

The Brahmaputra rises in the Chemayungdung glacier near Mansarovar and is called the Tsangpo (Yarlung Zangbo) in Tibet. It makes a U-turn around Namcha Barwa at the eastern syntaxis of the Himalaya and enters Arunachal Pradesh as the Siang or Dihang, becoming the Brahmaputra in Assam and the Jamuna in Bangladesh. It joins the Padma and then the Meghna before reaching the Bay of Bengal.

Majuli in Assam is among the world’s largest river islands. The Teesta rises in Sikkim, with the Rangeet as its tributary. The Barak, which rises in Manipur, belongs to the Meghna system and flows through Assam, not Arunachal Pradesh. The Brahmaputra carries heavy silt and braids, causing annual floods and bank erosion in Assam.

Peninsular River Systems

West-flowing Rivers

West-flowing rivers form estuaries, not deltas, because their courses are short, steep and over hard rock.

East-flowing Rivers

North to south order of key rivers: Penganga, Godavari, Krishna (with Bhima, Tungabhadra), Pennar, Kaveri, Periyar. The Godavari basin is the largest in Peninsular India and second only to the Ganga in India.

River Cities, Dams and Projects

Lakes of India

Waterfalls of India

Mains Dimension: Issues in India’s Drainage and Water Management

Floods

Floods are most severe in the Brahmaputra, Kosi and Ganga basins because of heavy rain, heavy silt loads, channel shifting and embankment failure. The Kosi’s 2008 breach displaced millions in Bihar. Coastal deltas such as the Mahanadi face floods during cyclones. Remedies include early warning, floodplain zoning, watershed management and better reservoir operation, rather than embankments alone.

Interstate Water Disputes

Water is a State subject (Entry 17, State List), but regulation of interstate rivers falls to Parliament under Entry 56, Union List, and Article 262 allows Parliament to set up tribunals through the Inter-State River Water Disputes Act, 1956.

River Linking

The National River Linking Project plans to move water from surplus to deficit basins. The Ken–Betwa link, agreed in 2021 between Uttar Pradesh and Madhya Pradesh, is the first project under the national plan, and the Godavari–Krishna link through Polavaram–Pattiseema has been completed. Critics point to ecological damage, displacement and high cost. A Mahanadi–Godavari link has been proposed, and Odisha has raised concerns about the Mahanadi surplus claim.

Pollution and Conservation

The Ganga Action Plan began in 1985 and Namami Gange was launched in 2014 with sewage treatment, ghat development and riverfront work. The Yamuna remains badly polluted at Delhi, and the main reason is sewage and over-abstraction rather than lack of source water, because the river is perennial. Gangetic dolphins are the national aquatic animal, with the National Dolphin Research Centre at Patna.

Likely Mains Questions

1. Compare the Himalayan and Peninsular drainage systems. (150 words)
2. Why do the rivers of the Peninsula form estuaries on the west and deltas on the east? (150 words)
3. Discuss the causes of recurrent floods in the Kosi and Brahmaputra basins and suggest measures. (250 words)
4. Examine the issues in interstate river water sharing and the role of tribunals. (250 words)
5. Evaluate the merits and demerits of the interlinking of rivers. (250 words)

Odisha Angle: Rivers and Lakes of Odisha

Odisha has about 11 river basins and is drained mainly by east-flowing rivers that fall into the Bay of Bengal. Most Odisha rivers are rain-fed and flood-prone in their delta stretches, and the Mahanadi, Brahmani and Baitarani together form a large combined delta system.

Chilika Lagoon

Chilika, in Puri, Khordha and Ganjam districts, is the largest brackish-water lagoon in India and was the first Indian wetland recognised as a Ramsar site (1981). It connects to the Bay of Bengal through a narrow outlet, hosts migratory birds, especially at Nalabana island, and supports Irrawaddy dolphins. Other Odisha features include the Bhitarkanika mangroves, Chandipur beach, and the Barehipani and Khandadhar waterfalls.

Drainage System of India MCQ and PYQ Practice