NEW DELHI: Flow in the Cauvery River has reached a historic low, raising water scarcity concerns in Tamil Nadu, Karnataka, Kerala and Puducherry.
Scanty rainfall across the Cauvery basin in the first half of July has triggered a severe water crisis in southern states, with river flow at the interstate point dropping to as much as 40 times below the required level.
Water flow from Karnataka to Tamil Nadu, Kerala and Puducherry has fallen to unprecedented levels, while reservoir storage has dropped sharply, with some reservoirs slipping below the 30-year average.
States are struggling to maintain even the minimum environmental flow in the river. The situation has worsened since June, when less than one-third of the required volume of water was released.
The Cauvery Water Regulation Committee (CWRC) has advised the states to conserve water and prioritise drinking water supply, industrial use and the maintenance of minimum environmental flow. It also said cropping activities should be planned based on water availability.
Water flow at Biligundlu, the interstate monitoring point between Karnataka and Tamil Nadu, has fallen to its lowest level since May 2023. The required daily flow in July is around 1 Thousand Million Cubic Feet (TMC), but the actual flow has ranged between 0.025 TMC and 0.043 TMC (around 300 to 500 cubic metres per second), or 23 to 40 times lower than required.
“The daily flow is nowhere near the required amount,” said Vineet Singh, Chairman of the CWRC. “Moreover, the current flow is insufficient to maintain the environmental flow of the river,” he added.
To maintain the river's environmental flow during peak summer, at least 0.083 TMC of water is required each day.
As a result, during the first 14 days of July, Karnataka released just 0.377 TMC, against the required flow of more than 14 TMC.
Tamil Nadu's Mettur reservoir currently holds 37.689 TMC, broadly in line with the 30-year average of around 36 TMC. At the same time last year, the reservoir held more than 93 TMC, close to full capacity.
Similarly, Karnataka's Krishnaraja Sagar (KRS) reservoir remains below its 30-year average. It currently holds 12.8 TMC, compared with the long-term average of 19.8 TMC.
In June, the total flow at the interstate point was only 2.9 TMC, against the required 9.19 TMC.
Tamil Nadu has sought the release of its allocated share of Cauvery water from Karnataka. However, Karnataka has expressed its inability to comply, citing inadequate water availability. CWRC officials have also said they are unable to direct Karnataka to release water because of the weak monsoon.
“Given the current water situation and the lack of any new monsoon systems forming in the next 10 days, we are unable to direct Karnataka to release water,” Singh told TNIE.
Singh said only a few days in the first week of July received better rainfall, but the precipitation remained meagre. He reiterated the need for both states to conserve water and prioritise drinking water, industrial use and the maintenance of environmental flow.