The Public Works Department (PWD) has delayed the discharge of water from Vaigai dam, even after issuing the third and final flood warning at 6 a.m. on Tuesday when the water level touched 69 feet.
“This being just unseasonal rain, we are waiting for the water level to further go up to 70 feet and then the release of the entire inflow will begin,” a PWD engineer said.
The water level in Vaigai dam stood at 69.39 feet with an inflow of 2,832 cusecs at 4 p.m. on Tuesday. As the final flood warning has been issued, water can be released from the dam anytime after water touches 70 feet.
While widespread rainfall has been reported in Theni, Dindigul and Madurai districts in the last couple of weeks, the release of water for irrigation from the dam has remained suspended for more than 10 days, leading to storage building in the reservoir.
Besides, the PWD officials have also been drawing water from Periyar dam in order to avoid surplussing of the reservoir towards the Kerala side.
“Only during the northeast monsoon from September to November, we keep the water level in Vaigai dam at 69 feet [maximum level 71 feet] to hold any sudden inflow of water. But this being unseasonal wet spell, we expect it to relent in the next couple of days and we do not want to waste the water now,” the engineer added.
Meanwhile, Chief Engineer, Madurai Region, N. Gnanasekar, says the Vaigai credit of water will be shared among the three reaches between Madurai and Ramananathapuram districts. Withdrawal of water from Periyar dam to Tamil Nadu will continue despite the Vaigai dam brimming with water.
“We will draw maximum water to avoid the water surplussing towards Kerala side as there is limitation to storage due to the rule curve method,” he adds.
The water level in Periyar reservoir can be raised up to the maximum permissible level of 142 feet in September. “We have got over 1,500 tanks downstream Vaigai dam. We will use every drop of water to fill up the tanks up to Big Tank in Ramanathapuram based on water sharing rule,” he says.
Water level
The water level on Tuesday in Mullaperiyar dam stood at 134.65 feet (maximum permissible level is 142 ft) with an inflow of 2,602 cusecs and discharge of 1,866 cusecs. In Vaigai dam, the water level at 6 a.m. at stood at 69 feet (71 ft) with an inflow of 2,630 cusecs and discharge of 69 cusecs. The combined storage in Periyar credit was 9,428 mcft.
The rainfall (in mm) recorded during the last 24 hours ending at 6 a.m. on Tuesday are as follows: Gudalur 53.4, Mullaperiyar dam 48.6, Thekkadi 42.4, Shanmuganadhi dam 21.3, Manjalar dam 19, Kodaikanal 14.8, Uthamapalayam 14.4, Viraganoor 11, Marudhanadhi dam 6.2, Peranai dam 4.6, Andipatti 4.2, Veerapandi, Vaigai dam and Sothupparai dam 4 each and Sathiyar dam 1
