The Kaveri (Cauvery) is designated as the ‘Dakshina Ganga’ or ‘the Ganga of the South’.
The Cauvery River rises at an elevation of 1,341 m at Talakaveri on the Brahmagiri range near Cherangala village of Kodagu (Coorg) district of Karnataka.
The total length of the river from origin to outfall is 800 km.
The Cauvery basin extends over states of Tamil Nadu, Karnataka, Kerala and Union Territory of Puducherry draining an area of 81 thousand Sq.km.
It 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 Nilgiris, an offshore of Western ghats, extend Eastwards to the Eastern ghats and divide the basin into two natural and political regions i.e., Karnataka plateau in the North and the Tamil Nadu plateau in the South.
Physiographically, the basin can be divided into three parts – the Westen 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.
The basin in Karnataka receives rainfall mainly from the S-W Monsoon and partially from N-E Monsoon. The basin in Tamil Nadu receives good flows from the North-East Monsoon.
Its upper catchment area receives rainfall during summer by the south-west monsoon and the lower catchment area during winter season by the retreating north-east monsoon.
It is, therefore almost a perennial river with comparatively less fluctuations in flow and is very useful for irrigation and hydroelectric power generation.
Thus the Cauvery is one of the best regulated rivers and 90 to 95 per cent of its irrigation and power production potential already stands harnessed.
The river drains into the Bay of Bengal. The major part of basin is covered with agricultural land accounting to 66.21% of the total area.
Tributaries of the Cauvery River
Left Bank: the Harangi, the Hemavati, the Shimsha and the Arkavati.
Right Bank: Lakshmantirtha, the Kabbani, the Suvarnavati, the Bhavani, the Noyil and the Amaravati joins from right.
The river descends from the South Karnataka Plateau to the Tamil Nadu Plains through the Sivasamudram waterfalls (101 m high).
At Shivanasamudram, the river branches off into two parts and falls through a height of 91 m. in a series of falls and rapids.
The falls at this point is utilized for power generation by the power station at Shivanasamudram.
The two branches of the river join after the fall and flow through a wide gorge which is known as ‘Mekedatu’ (Goats leap) and continues its journey to form the boundary between Karnataka and Tamil Nadu States for a distance of 64 km.
At Hogennekkal Falls, it takes Southerly direction and enters the Mettur Reservoir.
A tributary called Bhavani joins Cauvery on the Right bank about 45 Kms below Mettur Reservoir. Thereafter it enters the plains of Tamil Nadu.
Two more tributaries Noyil and Amaravathi join on the right bank and here the river widens with sandy bed and flows as ‘Akhanda Cauvery’.
Immediately after crossing Tiruchirapalli district, the river divides into two parts, the Northern branch being called ‘The Coleron’ and Southern branch remains as Cauvery and from here the Cauvery Delta begins.
After flowing for about 16 Kms, the two branches join again to form ‘Srirangam Island’.
On the Cauvery branch lies the “Grand Anicut” said to have been constructed by a Chola King in 1st Century A.D.
Below the Grand Anicut, the Cauvery branch splits into two, Cauvery and Vennar.
These branches divide and sub-divide into small branches and form a network all over the delta.
Floods in Cauvery Basin
The Cauvery 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.
Projects on Cauvery River
During the pre-plan period many projects were completed in this basin which included Krishnarajasagar in Karnataka, Mettur dam and Cauvery delta system in Tamil Nadu.
Lower Bhavani, Hemavati, Harangi, Kabini are important projects completed duing the plan period.
Industry in Cauvery Basin
The city of Bangalore is situated just outside this basin.
Important industries in the basin include cotton textile industry in Coimbatore and Mysore, cement factories in Coimbatore and Trichinapally and industries based on mineral and metals.
The Salem steel plant and many engineering industies in Coimbatore and Trichinapally are also situated in this basin.
The Pennar (also known as Uttara Pinakini) is one of the major rivers of the peninsula.
The Pennar rises in the Chenna Kasava hill of the Nandidurg range, in Chikkaballapura district of Karnataka and flows towards east eventually draining into the Bay of Bengal.
The total length of the river from origin to its outfall in the Bay of Bengal is 597 km.
Located in peninsular India, the Pennar basin extends over states of Andhra Pradesh and Karnataka having an area of ~55 thousand Sq.km
The fan shaped basin is bounded by the Erramala range on the north, by the Nallamala and Velikonda ranges of the Eastern Ghats on the east, by the Nandidurg hills on the south and by the narrow ridge separating it from the Vedavati valley of the Krishna Basin on the west.
The other hill ranges in the basin to the south of the river are the Seshachalam [famous for Red Sanders] and Paliconda ranges.
The major part of basin is covered with agriculture accounting to 58.64% of the total area.
Tributaries of Pennar River
Left Bank: the Jayamangali, the Kunderu and the
Right bank: the Chiravati, the Papagni etc.
Projects on Pennar River
Tungabhadra high level canal in Krishna basin irrigated areas in Pennar basin also. The only major project in the basin is the Somasila project.
Industry in Pennar Basin
The only important town in the basin is
With limited water and power potential and mineral resources, the scope for industrial development is limited in the basin.
There are no major industries. The existing small industries are mostly based on agricultural produce such as cotton weaving, sugar mills, oil mills, rice mills etc.
The Subarnarekha originates from the Ranchi Plateau in Jharkhand forming the boundary between West Bengal and Odisha in its lower course.
It joins Bay of Bengal forming an estuary between the Ganga and Mahanadi deltas. Its total length is 395 km.
The Brahmani river comes into existence by the confluence of the Koel and the Sankh rivers near Rourkela. It has a total length of 800 km.
The basin is bounded in the North by Chhotanagpur plateau, in the West and South by the Mahanadi basin and in the East by the Bay of Bengal.
The basin flows through Jharkhand, Chhattisgarh and Orissa States and drains into Bay of Bengal.
The Ponnaiyar is a small stream which is confined to the coastal area only.
It covers a small area in the state of Tamil Nadu, Karnataka and Andhra Pradesh.
The Basin is bounded on the North -West and South by various ranges of the Eastern Ghats like the Velikonda Range, the Nagari hills, the Javadu hills, the Shevaroy hills, the Chitteri hills and the Kalrayan hills and in the East by the Bay of Bengal.
South of the Cauvery delta, there are several streams, of which the Vaigai is the longest.
The Vaigai basin is an important basin among the 12 basins lying between the Cauvery and Kanyakumari.
This basin is bounded by the Varushanadu hills, the Andipatti hills, the Cardaman hills and the Palani hills on the West and by the Palk strait and Palk Bay on the East.
The Vaigai drains an area of 7,741 Sq.Km, which entirely lies in the state of Tamil Nadu.