Context: The Cauvery river, flowing through the southern Indian states of Karnataka, Kerala, and Tamil Nadu, has been a source of tension and dispute for decades, primarily concerning the allocation of water resources during times of distress. 

• The unpredictable nature of the southwest monsoon, which plays a vital role in replenishing the Cauvery's water levels, has brought the elusive distress-sharing formula to the forefront of discussions among the concerned states. 

• Recent submissions by Tamil Nadu and Karnataka, along with the deposition of the Cauvery Water Management Authority (CWMA) before the Supreme Court of India, emphasize the urgent need for an acceptable and equitable formula to address water scarcity during challenging times.

Cauvery River

• The Cauvery River rises at Talakaveri on the Brahmagiri range near Cherangala village of Coorg district of Karnataka.

• It flows in a southeasterly direction through the states of Karnataka and Tamil Nadu and descends the Eastern Ghats in a series of great falls.

• Before emptying into the Bay of Bengal south of Cuddalore, Tamil Nadu, the river breaks into a large number of distributaries forming a wide delta called the “garden of southern India.”

• Left Bank tributaries: The Harangi, the Hemavati, the Shimsha, and the Arkavati.

• Right Bank tributaries: Lakshmantirtha, the Kabbani, the Suvarnavati, the Bhavani, the Noyil, and the Amaravati.

Historical Background

• The idea of a distress-sharing formula has been under consideration since the interim ruling by the Cauvery Water Disputes Tribunal (CWDT) in June 1991.

• An attempt to have a distress-sharing formula was made in 2002-03 when the southwest monsoon yielded scant rain over a three-year block (2001-02 and 2003-04), with poor inflows to four reservoirs in upper-riparian Karnataka namely: Krishnaraja Sagar (KRS), Kabini, Hemavathy, and Harangi.

• Recent submissions by Tamil Nadu and Karnataka, as well as the Cauvery Water Management Authority's (CWMA) deliberations before the Supreme Court, highlight the critical need for a universally acceptable solution to this perennial issue.

Orders passed by judicial bodies

• The judicial bodies (CWDT and Supreme Court) had referred to the principle of proportional sharing in times of distress.

CWDT order 2007

• The Tribunal had suggested that in the event of there being two consecutive bad years of rain, the monthly schedule of water release be relaxed and all the reservoirs in the entire basin operated in an integrated manner to minimise any harsh effect.

Area of divergence

Disagreement Over Distress Sharing Formula

• Neither of the parties to the dispute nor the Authority has expressed anything against the concept of distress sharing.

• The divergence appears to be over what the elements of the proposed formula should be.

• Tamil Nadu takes into account the deficit in inflows to the four Karnataka reservoirs vis-à-vis the average flows in the last 30 years and the rainfall pattern in three groups of the Cauvery catchment.

• Catchment of the KRS and Kabini,

• Catchment upstream of Biligundulu on the inter-state border, and

• Catchment downstream of Biligundulu.

Karnataka's Concerns and Rights as an Upper Riparian State

• Karnataka, is against considering only the deficit in inflows into its reservoirs and has been maintaining that the overall distress situation cannot be calculated till the end of January.

• It has been said that the outcome of the northeast monsoon (October-December) should also be taken into account with that of the southwest monsoon (June-September).

• As an upper riparian State that is dependent on the southwest monsoon for irrigation, drinking water and more, Karnataka is well within its rights to be concerned about meeting its requirements for the next eight months.

• It had even informed the Court of its difficulties in releasing water given the “severe drought situation” in the Cauvery and Krishna basins.

Key highlights of Cauvery Water Management Authority (CWMA) Meeting

• The CWMA, deliberated on many factors that included the shortfall in inflows and rainfall, the monsoon forecast over the next fortnight, and inflows and outflows of four other reservoirs in the Cauvery basin.

• It was recorded that four Karnataka reservoirs had suffered a shortfall of 51.22% in their inflows, with the upper catchment of the Cauvery basin having had a more negative deficit in rainfall.

• The CWMA pointed out that the shortfall for Biligundulu, as compared to the stipulated flows in a normal year, was 62.4%.

• The Authority, endorsed the Cauvery Water Regulation Committee (CWRC) direction given to Karnataka to provide 5,000 cusecs for 15 days.

Conclusion

• The positions taken by Karnataka and Tamil Nadu may appear to be difficult to reconcile but this should not deter the Authority from trying to find a formula. Such an approach could and should have been used by the Authority after its inception in 2018. Unfortunately, nothing much was done in these five years.

• The CWMA may not have shown its mettle so far, but it should now try and make a fresh beginning. To begin with, the Authority along with its assisting body, the CWRC, should make the proceedings of all its meetings held so far available to the public on a website. Putting out all the facts in the public domain will help the CWMA dispel misconceptions in both States about this issue given that the Cauvery has always been an emotive subject.