After the river leaves the Kodagu hills and flows onto the Deccan plateau, it forms two islands, namely Srirangapatna and Shivanasamudra. It also drops into the Hogenakal Falls just before it arrives in the towns of Hogenakal and Srirangam in Tamil Nadu. In Tamil the name Hogenakal means smoking stone, because the fall of the water on the stones creates a mist, which gives the appearance of smoke. At Sivasamudra Island the river drops 320 ft (98 m), forming the famous Sivasamudram Falls known separately as Gagana Chukki and Bhara Chukki.
India's first hydroelectric plant was built in 1902 on the left falls and supplied power to the city of Bangalore. In 1906, Bangalore became the first city in Asia to be completely electrified and to have electric streetlights. The river enters Tamil Nadu in all splendour through the great falls at Hogenakkal. From there, it meanders into the southern plains. It is in the composite district of Thanjavur that the rich, silt-laden river delta region is formed before it empties into the Bay of Bengal through its two mouths.