Heavy rains in the catchment area of the Kabini and the Cauvery has augmented inflow into the reservoirs, which, the officials say, augurs well for the State’s ability to meet its obligation to Tamil Nadu this year.
The Kabini was in spate in many parts of Mysuru region as the authorities stepped up outflow from the dam at Beechanahalli at the rate of around 50,000 cusecs on Wednesday. This inundated the low-lying areas in the downstream of the reservoir, including the bathing ghats at Nanjangud, Suttur etc.
Discharge at the rate of 11,000 cusecs for 24 hours adds up to 1 tmcft of water. The discharge from the Kabini reservoir has roughly been 10 tmcft to 12 tmcft of water in the last three to four days alone.
“The cumulative inflow into the reservoir since June 1 is 42.337 tmcft against which 29.61 tmcft has been discharged so far,” according to a senior official in Cauvery Neeravari Nigama Ltd. (CNNL).
He told The Hindu that the current rate of outflow was inevitable as the water level has reached the optimum height and was hovering at 2,282.82 ft against the full reservoir level of 2,284 ft.
The official said a buffer of nearly 1 ft to 1.5 ft is maintained during peak monsoon as a safety measure, in case there is a surge in the inflow due to heavy rains.
“It would be risky to impound any more water — given the current rate of inflow and rains in the catchment area — as it would endanger the safety of the reservoir and also result in flash floods in the downstream regions,” he added.
Based on the information procured from their counterparts in Kerala, the dam authorities at Kabini are likely to further step up the discharge from the reservoir at Beechanahalli.
“We have information of heavy to very heavy rains around Mananthavady in Kerala which is the catchment area for the river and we expect the inflow to the river to further increase,” said the official. Besides, Papanashini, Taraka, and Nugu, the tributaries of Kabini, are overflowing and adding to the volume of inflow.
Besides, heavy rain in Kodagu has increased the inflow into the Krishnaraja Sagar (KRS).
The water level on Wednesday was hovering at 115.20 ft against the FRL of 124.80 ft. The rate of inflow was 35,968 cusecs and was bound to further increase in view of the current spell in the catchment areas of the Cauvery.