Kaveri river

Also called: Cauvery · Topic: Drainage System of India: Rivers, Basins and Patterns · NCERT: Class 11, Ch 3 "Drainage System"

Meaning

The Kaveri (Cauvery) is an east-flowing Peninsular river. It rises at Talakaveri in the Brahmagiri hills (1,341 m) of Kodagu (Coorg) district, Karnataka, flows 800 km through Karnataka and Tamil Nadu, and forms a delta in the Thanjavur area before it meets the Bay of Bengal. Its basin of 81,155 sq km covers Karnataka, Tamil Nadu and Kerala, plus Puducherry (Karaikal).

It matters because it gets rain from both the south-west and the north-east monsoons. Its flow changes less than that of any other Peninsular river, so it has been used heavily for irrigation and hydropower. It is also the subject of one of India's best-known inter-state water disputes.

Explanation

Why the Kaveri flows all year (a perennial river)

• Peninsular rivers are usually seasonal.
• They are rain-fed. They have no glaciers to feed them.

• So they carry a lot of water in the monsoon and little in summer.

• The Kaveri's catchment (the land that drains into the river) gets rain in two seasons.

• Upper catchment (Karnataka, Western Ghats): rain from the south-west monsoon in summer (June to September).

• Lower catchment (Tamil Nadu coast): rain from the north-east monsoon in winter (October to December).

• Result:

• The river gets fresh water twice a year.
• Its flow changes less than that of any other Peninsular river.
• This steady flow makes it very useful for irrigation and hydropower.

Basin and tributaries

• Basin share: 56% Tamil Nadu, 41% Karnataka, 3% Kerala. The largest share is in the downstream state, not in the state where the river rises.
• Main tributaries:
• Kabini: rises in Wayanad, Kerala.
• Bhavani and Amravati: flow in Tamil Nadu.
• Hemavati, Shimsha and Arkavathi: flow in Karnataka.

Course: landmarks from source to sea

1. Talakaveri, Brahmagiri hills, Kodagu, Karnataka. This is the source.
2. Krishnaraja Sagar (KRS) dam, near Mysuru, Karnataka.

3. Shivanasamudra falls, Karnataka. - The river splits around an island here. - One of India's early hydroelectric stations was built at these falls in 1902.

4. Hogenakkal falls, where the river enters Tamil Nadu.

5. Mettur dam (Stanley reservoir), Salem district, Tamil Nadu.
6. Srirangam, near Tiruchirappalli. It is a river island (land with river water on all sides) that lies between the Kaveri and its branch, the Kollidam (Coleroon).
7. Kaveri delta, in the Thanjavur area. - It is a rich rice area called the "garden of south India". - The ancient Grand Anicut (Kallanai) stands here. An anicut is a low wall built across a river to send its water into canals.

Why it ends in a delta

• A delta is a fan-shaped plain of river deposits where a river splits into many branches before it reaches the sea.
• How it forms:
• The river carries silt down from the plateau.
• The east coast has a gentle slope, and the Bay of Bengal has fairly weak tides.
• Silt settles at the mouth faster than the waves can carry it away, so the land at the mouth slowly builds up into a delta.

The Kaveri water dispute

• Upstream–downstream conflict: Karnataka holds the upper river and its dams, while Tamil Nadu's delta needs that water downstream.
• Timeline:
• 2007: the Cauvery Water Disputes Tribunal (CWDT) gave its final award. A tribunal is a special court set up to settle one dispute.
• 16 February 2018: the Supreme Court gave its judgment in State of Karnataka v. State of Tamil Nadu. It changed the award, and the award merged with the judgment. The CWDT was dissolved on 16 July 2018 [3].

• 2018: the Centre framed the Cauvery Water Management Scheme, 2018 under Section 6A of the Inter-State River Water Disputes Act, 1956. The scheme created the Cauvery Water Management Authority (CWMA) and the Cauvery Water Regulation Committee [2].

• Role of the CWMA: it controls how Kaveri water is stored, shared and released, so that the 2018 judgment is followed [2].

Where it occurs

• Karnataka:
• Source at Talakaveri (Brahmagiri hills, Kodagu district).
• KRS dam near Mysuru.
• Shivanasamudra falls.

• Tributaries Hemavati, Shimsha and Arkavathi.

• Kerala: the Kabini rises in Wayanad. Kerala has 3% of the basin.

• Tamil Nadu:
• Hogenakkal falls at the state border.
• Mettur dam in Salem district.
• Srirangam island near Tiruchirappalli.
• The delta and the Grand Anicut in the Thanjavur area.

• Tributaries Bhavani and Amravati.

• Puducherry: the Karaikal area lies in the basin.

• Mouth: the Bay of Bengal, on India's east coast.

Don't confuse with

• Godavari ("Dakshin Ganga"): the Godavari is the largest Peninsular river system (1,465 km). The Kaveri (800 km) is the shortest of the four big east-flowing rivers, but it is the least seasonal.
• Narmada and Tapi: these flow west through rift valleys (long valleys formed where land sinks between faults) and form estuaries (wide river mouths where the sea comes in). The Kaveri flows east and forms a delta.
• Kabini vs Bhavani/Amravati: all three are Kaveri tributaries. The Kabini rises in Kerala (Wayanad), while the Bhavani and Amravati flow in Tamil Nadu.
• CWDT vs CWMA: the CWDT was the tribunal that gave the 2007 award and was dissolved in 2018 [3]. The CWMA is the permanent body under Section 6A of the ISRWD Act, 1956, and it carries out the 2018 judgment [2].

Prelims Hooks

• Source: Kaveri → Talakaveri, Brahmagiri hills (1,341 m), Kodagu, Karnataka.
• Trap: the Kaveri basin covers three states plus Puducherry (Karaikal). The largest share is Tamil Nadu (56%), not Karnataka (41%).
• Order by length: Godavari (1,465 km) > Krishna (1,401 km) > Mahanadi (851 km) > Kaveri (800 km).
• Why it is the least seasonal Peninsular river: it gets rain from both the south-west monsoon (upper catchment) and the north-east monsoon (lower catchment).
• Dam/landmark–state pairs: KRS (near Mysuru, Karnataka), Shivanasamudra (Karnataka, 1902 hydel station), Hogenakkal (entry into Tamil Nadu), Mettur/Stanley reservoir (Salem, Tamil Nadu), Srirangam island (Kaveri–Kollidam, near Tiruchirappalli).
• The Cauvery Water Management Authority was created under Section 6A of the ISRWD Act, 1956, after the Supreme Court judgment of 16 February 2018 [2].

Mains Points

• Inter-state water conflict (GS-I/II):
• In dry years the rain-fed river carries less water.
• Upstream Karnataka stores water behind dams such as KRS, so downstream Tamil Nadu's delta gets less.
• The tribunal took a long time to decide (CWDT, 1990–2007).

• The CWMA, a permanent body that carries out the award, is a possible model for other river basins [2].

• Agriculture and economy (GS-I/III):

• Rain from two monsoons gives the river a steady flow.
• This explains its early and heavy use for irrigation, from the ancient Grand Anicut to Mettur, and for power at Shivanasamudra (1902).

• The result is the Thanjavur delta, the "garden of south India" and one of the main rice belts on the east coast.

• Interlinking of rivers (GS-III):

• The Kaveri is a receiving basin. Links such as Mahanadi (Manibhadra)–Godavari (Dowlaiswaram) and Polavaram's 80 TMC transfer to the Krishna aim to move "surplus" water south towards the Krishna, Pennar and Kaveri basins [4][5].
• Concerns: tribal land that will go under water, less silt reaching the deltas (which can make them shrink), and disputes over how much water is truly "surplus".

Related concepts

• Mahanadi river
• Godavari river
• Krishna river

Read more

• The east-flowing Peninsular rivers: Mahanadi, Godavari, Krishna and Kaveri