Cauvery Basin extends over an area of 87,900 km2 which is nearly 2.7% of total geographical area of the country. The basin lies in the states of Tamil Nadu (48,730 km2), Karnataka (36,240 km2) and Kerala (2,930 km2).

Cauvery river rises at Talakaveri on the Brahmagiri range in the Western Ghats in Karnataka at an elevation of about 1341 m and flows for about 800 km before its outfall into the Bay of Bengal. The important tributaries joining the Cauvery are the Harangi, the Hemavati, the Kabini, the Suvarnavathi and the Bhavani.

Physiographically, the basin can be divided into three parts - the Western Ghats, the Plateau of Mysore and the Delta. The delta area is the most fertile tract in the basin. The principal 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.

An average annual surface water potential of 21.4 km3 has been assessed in this basin. Out of this, 19.0 km3 is utilisable water. Culturable area in the basin is about 5.8 Million ha, which is 3.0% of the total culturable area of the country.

Present use of surface water in the basin is 18.0 km3. Live storage capacity in the basin has increased significantly since independence. From just about 4.1 km3 in the pre-plan period, the total live storage capacity of the completed projects has increased to 7.4 km3. In addition, a storage quantity of over 0.3 km3 would be created on completion of projects under construction. An additional storage to the tune of over 0.3 km3 would become available on execution of projects under consideration. The hydropower potential of the basin has been assessed as 1359 MW at 60% load factor.

Source: MINISTRY OF WATER RESOURCES
GOVERNMENT  OF  INDIA