The water level in the Mullaperiyar dam crossed 136 ft on Friday evening, a first since 1979. The Supreme Court on May 6 allowed Tamil Nadu to raise the water level in the dam from 136 to 142 ft.
The water level touched 136 ft at 4 p.m. and was rising, an official of the Tamil Nadu Public Works Department told The Hindu.
On Thursday, the five-member sub-committee, under the expert committee set up by the Supreme Court, monitored the water and seepage levels to set in motion a visit of the expert panel on November 3.
The spurt in the water level followed heavy rain and Tamil Nadu reducing offtake of water from the dam after the reservoirs downstream reached full capacity following heavy rain.
The PWD had repaired the spillway shutters and enhanced security measures to increase the reservoir level after the apex court order.
The official said Tamil Nadu was drawing water at 456 cubic ft per second on Friday where as the inflow was 1,912 cubic ft per second.