Cauvery issue comes to a boil as Supreme Court cuts TN's share

The Supreme Court directed Karnataka on Friday to release only 177.25 tmcft (thousand million cubic feet) of Cauvery water — instead of the originally agreed upon 192 tmcft — to Tamil Nadu, in a development that is likely to reshape southern India's politics.

The top court warned the two states not to flout its order or use the allotted water for any other purpose other than specified.

The court partially modified the verdict of the Cauvery Water Dispute Tribunal (CWDT) and reduced TN's share, seeking to end a long-running dispute that has often sparked violence. The court upheld the allocation of 30 tmcft to Kerala and 7 tmcft to Puducherry, as decided by the CWDT. The crucial verdict comes ahead of Karnataka's Assembly election slated for April, prompting the ruling Congress there to claim victory.

A bench led by CJI Dipak Misra allocated 14.75 tmcft of water to Karnataka, over and above the 270 tmcft decided by the CWDT.

Of the 14.75 tmcft, 4.75 TMC will be only for Bengaluru's drinking water needs. Also called the Ganga of the south, the Cauvery is the largest river in southern India and is considered a lifeline for both states.

The judgment, authored by CJI Misra, justified the decrease of water supply to Tamil Nadu by clarifying that the CWDT had not taken into account the state's stock of an "empirical" 20 tmcft of groundwater. The apex court reasoned that it considered at least 10 tmcft of this groundwater, thus allowing the reduction of supply from Karnataka.

Largely upholding the CWDT's order, the apex court relied on a previous judgment which held "that waters of an inter-state river passing through corridors of the riparian states constitute a national asset and no single state can claim exclusive ownership of its water."

The court said Bengaluru has attained a "global status" and its drinking water requirement has increased multi-fold. The bench reasoned that drinking water was at the top of the hierarchy and Bengaluru was running dry.

The top court pointed out that the tribunal had not considered Bengaluru's growing needs, and miscalculated that the city could sustain with its 60 per cent groundwater supply, which has dried up with its burgeoning population.

According to the 465-page judgment, till a scheme for water sharing is not formulated, the current arrangement will stand unchanged for the next 15 years.

The Cauvery, originating in Karnataka and flowing into Tamil Nadu, has been the source of a bitter dispute since 1892, as farmers in both states depend on the almost 800km-long river for sustenance.

The top court's judgement has sought to bring a closure to the dispute that has remained the main bone of contention between the two states since the British era.

Post-independence, the issue arose once again when the state borders were re-organised in 1956.

The CWDT calculated water inflow to Tamil Nadu between 1980 and 1990. In 1991, the tribunal passed an interim order, directing Karnataka to ensure that Tamil Nadu received 205 tmcft of water per annum. The CWDT also directed Karnataka to stop its plan to increase its irrigated land area.

However, in 2007, the CWDT pronounced its final order, saying that of the total available 740 tmcft of water, Tamil Nadu would receive 419 tmcft, Karnataka 270 tmcft, Kerala 30 tmcft and Puducherry would get 7 tmcft.

The matter came to a head in 2016 when Karnataka was reluctant to release water to its neighbour, causing Tamil Nadu to approach the top court for a final resolution. When the court refused Karnataka's plea to stop the temporary release of water, riots broke out in both states.

In September 2017, the top court reserved its judgment on the appeals filed by the states against the CWDT's final judgment.

What’s the dispute?

• K’taka is upper riparian state, TN is the lower riparian one. Cauvery water was divided according to British-era agreements, but two states have been fighting in courts.
• The 802-km-long river originates in southern K’taka and flows into TN, Kerala and Puducherry. It is the lifeline for the two warring states. 
• In 1991, riots in B’luru left 18 dead. In September 2016, there was large-scale violence in India’s IT hub. One dead.