The Kerala government highlighted in the Supreme Court the Supervisory Committee for Mullaperiyar dam’s inability to prepare and implement the gate operation schedule for flood management as well as the instrumentation scheme of the dam.
Kerala said Tamil Nadu, as a result, was still adopting an “obsolete” gate operation schedule, which dates back to 1939.
In its affidavit, Kerala informed the court that a Central Water Commission (CWC) inspection report had said 70% of the installed instruments for monitoring the safety and health of the dam were not working properly. Also, Tamil Nadu was yet to install the two seismoaccelerographs recommended to monitor the seismic behaviour of the dam.
A Bench, led by Justice A.M. Khanwilkar, on Monday gave Tamil Nadu government lawyer, advocate G. Umapathy, two weeks to submit a response to the affidavit.
“The absence of a gate operation schedule at Mullaperiyar reservoir creates an element of uncertainty in the very management of the entire Periyar system by Kerala during the recent floods... The gate operation schedule and rule curves of the dam are very essential for planning disaster management and ensuring the safety of the people living downstream. It is the very reason for Kerala to insist that the supervisory committee finalise the schedule without further delay, considering the lurking danger of such moderate flash floods which occur frequently,” Kerala said in its affidavit.
With the onset of the monsoon drawing close, Kerala referred to a CWC Hydrology directorate report of 2014 that had not approved of a draft spillway gate operation schedule prepared by Tamil Nadu.
“The suggested operation till reservoir level rises to +140 ft during monsoon and +140 ft during other period is not appropriate. During flood event, it would be difficult to contain the floods at +142 ft if no operation is carried out till 140 ft level as proposed,” the CWC had said.
Kerala noted how Tamil Nadu had delayed a review of the gate operation schedule, saying it needed rainfall data from the Mullaikodi rain gauge station. Kerala said Tamil Nadu had not even shared with it the draft schedule and rule curves submitted to the CWC.
“A single rain gauge station at Mullaikodi does not reflect the actual rainfall of the entire catchment and the above rain gauge data is not going to yield any qualitative improvement to the operation schedule,” Kerala said.
Kerala said its work establishing an inflow forecasting system in the catchment area of the dam was progressing. “The work on the installation of the automatic weather station and real-time rain gauges in the catchment area is progressing,” it said. In October last, the Tamil Nadu government had rebutted allegations made in the Supreme Court that the supervisory committee had “abdicated its duties” to evaluate the safety of the structure and water levels.
The State countered allegations that the supervisory committee, constituted by the Centre on the basis of an SC judgment in the Mullaperiyar case in May 2014, had “delegated” its duties to a sub-committee.
The court was hearing a petition filed by Dr. Joe Joseph and the office-bearers of the Kothamangalam block panchayat in Kerala, who expressed their apprehension about the lack of proper supervision of water levels in the over-a-century-old dam located along the Periyar tiger reserve.