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Pennaiyar river dispute: Supreme Court directs Centre to form tribunal

03 Feb 2026 GS 1 Geography
Pennaiyar river dispute: Supreme Court directs Centre to form tribunal Click to view full image

Why in news

The Supreme Court of India has directed the Union Government to constitute an inter-State river water disputes tribunal to adjudicate the long-pending dispute between Tamil Nadu and Karnataka over the sharing of Pennaiyar river waters.

Key directions of the Supreme Court

  • A Bench headed by Justice Vikram Nath ordered the Centre to notify the tribunal within one month.

  • The direction was issued under Section 5 of the Inter-State River Water Disputes Act, 1956.

  • The Court allowed Tamil Nadu’s complaint to be formally placed before the tribunal once it is constituted.

Background of the dispute

  • Pennaiyar River is an inter-State river, flowing from Karnataka to Tamil Nadu.

  • In 2018, Tamil Nadu approached the Supreme Court alleging that:

    • Karnataka was constructing dams and diversion structures on the river.

    • Such actions would prejudice downstream flows to Tamil Nadu.

Arguments by Tamil Nadu

  • No State has exclusive ownership over waters of an inter-State river.

  • Flowing water of an inter-State river is a national asset.

  • The 1892 agreement governing Pennaiyar river waters is valid and binding on both States.

  • Karnataka should be restrained from initiating new schemes in the Pennaiyar basin until adjudication by a tribunal.

Ponnaiyar river (South Pennar / Dakshina Pinakini / Thenpennai)

Basic information

  • Also known as:

    • Dakshina Pinakini (Kannada)

    • Thenpennai / Ponnaiyar / Pennaiyar (Tamil)

  • Type: Inter-State river

  • Country: India

  • States: Karnataka and Tamil Nadu

  • Empties into: Bay of Bengal

Source and course

  • Source: Nandi Hills, Chikkaballapura district, Karnataka

  • Mouth: Near Cuddalore, Tamil Nadu

  • Length: ~500 km (497 km in Tamil Nadu)

  • Status: Second longest river in Tamil Nadu after the Kaveri

Major cities and settlements along the river

  • Chikkaballapura

  • Bangalore

  • Hosur

  • Krishnagiri

  • Kaveripattinam

  • Tiruvannamalai

  • Cuddalore

Important for Prelims: The river flows through major industrial belts, especially around Bangalore and Hosur.

Tributaries

  • Left bank: Pambar River

  • Right bank: Vanniyar River

Basin and hydrology

  • Catchment area: ~3,690 sq km (spread across Karnataka and Tamil Nadu)

  • Nature: Mostly seasonal river

  • Water flow depends on:

    • South-West monsoon (upper catchment in Karnataka)

    • North-East monsoon (Tamil Nadu)

  • Plays a major role in:

    • Groundwater recharge

    • Feeding tanks and reservoirs in northern Tamil Nadu

Dams and infrastructure

  • Kelavarapalli Dam – near Hosur

  • Krishnagiri Dam – near Krishnagiri

  • Sathanur Dam – near Tiruvannamalai

    • Largest dam on the river

    • Gross capacity: ~7.3 Tmcft

Environmental concerns

  • Severe pollution due to:

    • Industrial effluents

    • Urban sewage, especially from Bangalore

  • Sewage inflow through:

    • Bellandur Lake

    • Varthur Lake

  • The old course of Dakshina Pinakini is stated to have disappeared.

Historical and cultural significance

  • References found in:

    • Sangam literature

    • Tevaram (Bhakti period) hymns

  • Historically described as a perennial river with rich vegetation

  • Important religious sites on its banks include:

    • Penneswaraar Temple

    • Veerateshwarar Temple

    • Kabilar Kundru

    • Shree Venkateshwara Swamy Temple (Dakshina Tirupati)

Prelims Practice MCQs

Q. With reference to the Ponnaiyar (South Pennar) River, consider the following statements:

  1. It originates in the Nandi Hills of Karnataka.

  2. It is the longest river entirely within Tamil Nadu.

  3. It drains into the Bay of Bengal.

Which of the statements given above is/are correct?
(a) 1 and 3 only
(b) 2 only
(c) 1 and 2 only
(d) 1, 2 and 3

Correct answer: (a)

Explanation:

  • Statement 1 is correct: Origin is Nandi Hills, Karnataka.

  • Statement 2 is incorrect: It is the second longest river in Tamil Nadu, after the Kaveri.

  • Statement 3 is correct: It empties into the Bay of Bengal near Cuddalore.

Q. Which of the following rivers are tributaries of the Ponnaiyar River?

  1. Pambar River

  2. Vanniyar River

  3. Bhavani River

Select the correct answer using the code below:
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3

Correct answer: (b)

Explanation:

  • Pambar is a left-bank tributary.

  • Vanniyar is a right-bank tributary.

  • Bhavani is a tributary of the Kaveri, not Ponnaiyar.



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