The Kaveri basin extends over states of Tamil Nadu, Karnataka, Kerala and Union Territory of Puducherry.
It drains an area of 81,155 Sq.km which is nearly 2.7% of the total geographical area of the country.
34,273 Sq. Kms. lies in Karnataka
43856 Sq. Kms. in Tamil Nadu
2866 Sq. Kms. in Kerala
160 Sq. Kms in Union Territory of Puducherry
The Kaveri basin is bounded by the Western Ghats on the west, by the Eastern Ghats on the east and the south and by the ridges separating it from Krishna basin and Pennar basin on the north.
The Kaveri River rises at an elevation of 1,341 m at Talakaveri on the Brahmagiri range near Cherangala village of Kodagu district of Karnataka.
The river drains into the Bay of Bengal.
The total length of the river from the origin to its outfall into the sea is 800 Kms. of which 320 Kms.is in Karnataka, 416 Kms.in Tamil Nadu and 64 Kms. forms the common border between the Karnataka and Tamil Nadu states.
The Kaveri basin is fan-shaped in Karnataka and leaf-shaped in Tamil Nadu.
The run-off does not drain off quickly because of its shape and therefore no fast raising floods occur in the basin.
The basin receives rainfall mainly from the S-W Monsoon and partially from N-E Monsoon in the Karnataka.
The basin in Tamil Nadu receives good flows from the North-East Monsoon.
The delta area of the basin is the most fertile tract in the basin.
Soil types found in the basin are black soils, red soils, laterites, alluvial soils, forest soils and mixed soils.
Red soils occupy large areas in the basin.
Alluvial soils are found in the delta areas.
The cultivable area of the basin is about 5.8 M. ha, which is about 3% of the cultivable area of the country.
Left bank tributaries: the Harangi, the Hemavati, the Shimsha and the Arkavati
Right bank tributaries: the Lakshmantirtha, the Kabbani, the Suvarnavati, the Bhavani, the Noyil and the Amaravati
The Amaravati River begins at the Kerala/Tamil Nadu border at the bottom of Manjampatti Valley between the Annamalai Hills and the Palni Hills in Indira Gandhi Wildlife Sanctuary and National Park in Tirupur district. It joins with the Kaveri at Thirumukkudal, about 10 kilometers from Karur.
The Kabini is an important tributary of the Cauvery. It is a perennial river and has a course of about 240 Kms. It rises in the Western Ghats in North Wynad in Kerala State as two streams i.e. the Mannantoddypuzha and Panamarampuzha. It joins the Cauvery at Tirumakudalu Narasipur (T.N.Pur) and this confluence point is being considered as a spot of great sanctity. The confluence point is also called as “Triveni Sangam”.
The Bhavani is a perennial river of South India, rising in Attappadi valley in Kerala. It enters Tamilnadu near Mannar and traverses from West to East for 170 Kms. and joins the Cauvery near Bhavani Town. It principally receives runoff from the South-West monsoon and occasional floods during North- East Monsoon.