The opening of the spillway shutters of Mullaperiyar dam made little impact on the downstream Idukki reservoir by Friday evening.
Saju M.P., assistant engineer, Kerala State Electricity Board (KSEB), told The Hindu that the water released from the Mullaperiyar dam was very less when compared to the reservoir area of Idukki, one of the largest in Asia. The water released was at 534 cusecs (cubic feet per second) which was not enough to make an impact on Idukki reservoir, he said.
Red to orange
The water level in the reservoir fell from 2,398.31 ft (red alert level) in the morning to 2,398.30 ft (orange alert level) by evening. The fall in the water level is attributed to the near absence of rainfall on the catchment area and the reduced inflow through the main tributary, the Periyar.
Mr. Saju said it would take at least two to three days to know what impact the release of water from Mullaperiyar made on Idukki reservoir.
The water released from the Mullaperiyar dam in the morning reached Idukki reservoir by noon. A dam safety official said an inflow of at least 2 mcm (million cubic metres) of water was needed to make any impact on Idukki reservoir in the present situation. At least 16 mcm water should flow into the reservoir for the water level to increase by one foot, he said. Power generation in the Moolamattom power plant of Idukki reservoir was at the maximum.
The upper rule curve level of Idukki dam is set in a way to accommodate the water released from Mullaperiyar dam as per the new rule curve level set by the Central Water Commission (CWC) for the two dams.
Rising in Mullaperiyar
Because of good inflow, the water level in the Mullaperiyar rose after the opening of the spillway shutters at 7.30 a.m. on Friday. The water level was 138.75 ft at 7 a.m. and it rose to 138.85 ft at 6 p.m. Tamil Nadu was drawing water at 2,335 cusecs while the average inflow was 3,744 cusecs on Friday.
KSEB sources said Kerala was pressurising Tamil Nadu to release more water from the dam as the upper rule curve for the dam till October 31 is 138 ft.
