The spell of rain which recently battered Bengaluru has turned out to be a bonanza for two reservoirs of Tamil Nadu.
The reservoirs in question – Krishnagiri and Sathanur – have been receiving huge inflows in recent days. They have reached almost full level or capacity. Built across the river Ponnaiyar, the dams, ordinarily, release flood flows during the northeast monsoon following rain in the local catchment areas. “It is very uncommon to find such flows in the Ponnaiyar river well before the onset of the monsoon,” says a senior official of the Public Works Department. The heavy rainfall that lashed Bengaluru has yielded bountiful inflows. On Tuesday, Krishnagiri recorded an inflow of 2,349 cubic feet per second (cusecs) and Sathanur 3,020 cusecs.
The flood flows, ranging from 1,860 cusecs to 2,880 cusecs, are being released from the two dams.
Originating near Hongashenhalli village in Kolar district of Karnataka, Ponniayar touches Bengaluru district before entering Dharmapuri district of Tamil Nadu. It traverses through Vellore, Tiruvannamalai, Cuddalore and Villupuram districts. In the last leg of 70 km, the river branches into Gadilam and Ponniayar before draining into the sea. Gadilam joins the Bay of Bengal near Cuddalore and the Ponnaiyar near Puducherry
Meanwhile, other irrigation reservoirs of the State are just half full. As on date, the combined storage of the reservoirs, numbering 15, accounts for about 55% of the total capacity. On the same day (October 19) last year, the combined storage was not even one-fourth of the total capacity.
In terms of thousand million cubic feet (TMC), the combined storage of the 15 reservoirs was 109.023 TMC against the total capacity of 195.48 TMC. Last year, the figure was 45.978 TMC.
Mettur and Bhavanisagar reservoirs, both in western districts, have nearly two-thirds and one half of their respective capacity. Mullaperiyar and Vaigai, which serve farmers in the southern belt, have storage of about 40% of their capacity. While Manimuthar has hardly 10% of its capacity, the storage of Papanasam, Pechiparai and Perunchani reservoirs varies from about 33% to 28%.
In the network of Parambikulam-Aliyar dams, only Sholayar has water to the tune of about 80% of its capacity, while Thirumurthy’s storage is around 70%; Parambikulam’s is half full and Aliyar is about 40% full.
As for the realisation of Cauvery water, Tamil Nadu received around 90 TMC from June 1 to October 16 against its share of 145 TMC for the corresponding period. Of this figure, about 62 TMC was realised during September 1 till the middle of this month.
