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The Krishna River is the fourth-biggest river in terms of water inflows and river basin area in India, after the Ganga, Godavari and Brahmaputra. 

Kaveri, is an Indian river flowing through the states of Karnataka and Tamil Nadu. The Kaveri river rises at Talakaveri on the Brahmagiri range in the Western Ghats, Kodagu district of the state of Karnataka, at an elevation of 1341m above mean sea level and flows for about 800 km before its outfall into the Bay of Bengal.

The Vaigai is a river in the Tamil Nadu state of southern India; it passes through the towns of Theni, Andipatti and Madurai.

The Penna also known as Pennar, Penner, Penneru and uttara pinakini is a river of southern India. The Penna rises in the Nandi Hills in Chikballapur District of Karnataka state, and runs north and east through the states of Karnataka and Andhra Pradesh to empty into the Bay of Bengal.