Chennai, The Tamil Nadu government, which manages the Mullaperiyar dam although it is geographically in Kerala's Idukki district, opened two spillway shutters on Friday.
The two shutters were opened at 7.29 a.m., according to the state Water Resources Department officials.
Kerala Revenue Minister K. Rajan also confirmed that the two shutters of the dam were opened and that 300 families at Vallakadavu in Idukki district which is in downstream of the dam were evacuated to relief camps.
After incessant rains at the catchment area of the dam in Kerala, there have been calls to open the shutters and to release the excess water.
A Supreme Court-appointed supervisory committee has directed the two states to maintain the water level at 138 ft till October 30 and then at 139.5 ft until November 10.
A division bench of the Supreme Court comprising of Justice A.M. Khanwilkar, Dhinesh Maheswari, and C.T. Ravikumar in a judgment on Thursday said that the two states would abide by the water level suggested by the supervisory committee and the committee would monitor the situation of water level in the dam on an hourly basis.
The case will next be heard on November 11.
The Supreme court granted the adjournment after Kerala sought time to file an affidavit and raised objections regarding the rule-curve criteria adopted by the Tamil Nadu side.
The upstream of the Mullaperiyar dam is in Tamil Nadu, while the downstream is in Kerala and hence the latter argued to maintain the water level at 139 ft and not the 142 ft as proposed by the former.
Mullaperiyar is a masonry gravity dam on the Periyar river and operated and maintained by Tamil Nadu. It was constructed between 1887 and 1895 by the British engineer John Pennycuick.
In a report released in January this year, the UN said that Mullaperiyar is one among the big dams in the world to be decommissioned as it is situated in a seismically active area.
The report also said that there were significant structural flaws and if the dam was to fail it would affect the lives of 3.5 million people in Kerala.