The east-flowing rivers of India are a prominent feature of the peninsular drainage system, originating mostly in the Western Ghats or Central Highlands and flowing eastward to drain into the Bay of Bengal. They are characterized by several distinct features:

1. Origin and Flow Direction: Most major east-flowing rivers, such as the Godavari, Krishna, and Cauvery, originate in the Western Ghats, which act as a water divide. They traverse the Deccan Plateau from west to east, following the general slope of the peninsular landmass, before emptying into the Bay of Bengal. The Mahanadi originates in the Central Highlands of Chhattisgarh.

2. Large Drainage Basins: These rivers typically have extensive drainage basins, covering significant areas of the peninsular plateau. For example, the Godavari has the second-largest river basin in India, after the Ganga.

3. Perennial but Monsoon-Fed: While considered perennial, their water volume fluctuates significantly with the monsoon seasons. They are primarily fed by the southwest monsoon rainfall, leading to high flows during the rainy season and reduced flows during the dry months.

4. Formation of Deltas: A most striking feature is the formation of large, fertile deltas at their mouths before joining the Bay of Bengal. These deltas are formed by the deposition of vast amounts of silt and sediment carried by the rivers. Examples include the Mahanadi Delta, Godavari Delta, Krishna Delta, and Cauvery Delta. These deltas are highly productive agricultural regions and support dense populations.

5. Extensive Network of Tributaries: Each major east-flowing river is supported by a vast network of tributaries that collect water from various parts of its basin. For instance, the Godavari is joined by the Purna, Wardha, Pranhita, Manjira, Wainganga, and Penganga. The Krishna has the Bhima, Tungabhadra, and Koyna as important tributaries.

6. Economic Significance: These rivers are lifelines for the peninsular states, providing water for extensive irrigation, supporting agriculture (especially rice cultivation in the deltas), and serving as sources for hydroelectric power generation. They also support inland fisheries and provide domestic water supply.

7. Nature of Flow: Due to their long courses across the plateau, these rivers generally have a relatively gentle gradient in their lower reaches, contributing to sediment deposition and delta formation. However, in their upper reaches, they may exhibit rapids and waterfalls, suitable for hydropower generation.

Major East-Flowing Rivers:

• Mahanadi: Originates in Chhattisgarh, flows through Odisha, forms a large delta. Known for the Hirakud Dam.
• Godavari: The 'Dakshin Ganga' (Ganga of the South), originates in Nashik, Maharashtra. It is the longest peninsular river, flowing through Maharashtra, Telangana, and Andhra Pradesh, forming a large delta.
• Krishna: Originates near Mahabaleshwar, Maharashtra. Flows through Maharashtra, Karnataka, and Andhra Pradesh/Telangana, forming a combined delta with the Godavari. Known for the Nagarjuna Sagar Dam.
• Cauvery: Originates in the Brahmagiri hills of Karnataka. Flows through Karnataka and Tamil Nadu, forming a fertile delta. It is a highly revered river and a source of significant inter-state water disputes.
• Other smaller rivers: Subarnarekha, Brahmani, Baitarani, Penner, Palar, and Vaigai also flow eastward into the Bay of Bengal.

In summary, the east-flowing rivers are vital arteries of peninsular India, shaping its geography, economy, and culture through their extensive basins, fertile deltas, and significant water resources.