CHENNAI: With the southwest monsoon failing to deliver adequate rainfall and summer-like heat persisting even in August, the combined storage across the state’s 90 reservoirs stood at 83.124 thousand million cubic feet (tmcft) on Sunday, just 37.05% of their total capacity of 224.343 tmcft, according to Water Resources Department (WRD) data accessed by TNIE.
In the same period last year, the combined storage stood at 189.545 tmcft, about 47% higher than at present. Barring the Gundar reservoir in Tenkasi district, which has reached its full capacity of 18.43 million cubic feet (mcft), none of the state’s other reservoirs is anywhere close to full this year.
While the state is managing to meet drinking water needs for now, a senior WRD official said, maintaining the balance between demand and supply is becoming increasingly difficult in areas that depend heavily on these reservoirs.
Of the 90 reservoirs, 58 are below 25% capacity, 14 are between 26% and 50%, 15 are between 51% and 76%, and only two have crossed 80%. Mettur, the main source of water for irrigation in the agricultural heartland districts, holds 43.275 tmcft — 46.30% of its 93.470 tmcft capacity — on Sunday, against 91.114 tmcft (97.48%) at the same time last year. “Though the Cauvery stretch from Mettur to Tiruchy has normal flow and water is available, the downstream and tail-end districts are facing an acute shortage, even for drinking water,” the official told TNIE.
In contrast, Karnataka’s four major Cauvery-linked reservoirs, which feed into Mettur, are comparatively well-stocked. Krishnaraja Sagar (KRS) is at 63.64%, Kabini at 92.31%, Harangi at 97.06% and Hemavathy at 86.56% as of Saturday. Despite this, the official said, Karnataka had not released its stipulated share of Cauvery water.
As per the Supreme Court’s final order, it was required to release 9.190 tmcft in June and 31.240 tmcft in July, but Tamil Nadu received only 2.915 tmcft and 0.7138 tmcft, respectively. “It is doubtful whether Mettur reservoir will reach its full capacity this season,” the official said.
TN to rely more heavily on northeast monsoon
Other major irrigation reservoirs, including the Bhavanisagar, Amaravathi and Vaigai, are also reporting poor storage. With
the southwest monsoon underperforming, Tamil Nadu will have to rely more heavily on the northeast monsoon later this year to replenish its reservoirs.