Cyclone Fengal: Water release from Sathanur judicious, made to avert catastrophe as dam's structure was at risk, says Duraimurugan

CHENNAI: Stating that opposition parties have resorted to spreading misinformation regarding the discharge of surplus water from the Sathanur reservoir for their "political gain" in the wake of the unprecedented rainfall due to Cyclone Fengal in the catchment area of the Thenpennai River, Minister for the Water Resources Department (WRD) Duraimurugan said the department strictly followed the flood rules and regulations of the Sathanur Dam before releasing flood water from the upstream of the river.

The government had taken precautionary measures and discharged water from Sathanur in a judicious manner, ranging from 1,500 cusecs to 1.80 lakh cusecs between December 1 and 2, he said. This judicious action averted major damage and loss of life, he claimed. Experts and the public have realised that the government acted appropriately and minimised damage to crops and property, Duraimurugan said in a five-page statement on Tuesday.

The opposition parties have been spreading rumours on such critical issues without any conscience, said the minister. However, their false campaign will fail.

The reservoir was brimming with over 7 thousand million cubic feet (tmc) of water, against its full storage capacity of 7.321 tmc. The officials discharged the inflow downstream to ensure the safety of the structure and avert major damage, he said.

"If we had not discharged 1.80 lakh cusecs of water after the fifth flood alert was issued at 2.45 am on Dec 2, it would have caused significant damage to the reservoir and resulted in dumping seven tmc of water downstream.

"If that had happened, we could not imagine the extent of the destruction," said the minister, who also applauded the officials for acting appropriately and managing the inflow and outflow of water to the reservoirs across the Thenpennai basin, including Krishnagiri and Sathanur.

Explaining the chain of events after the cyclone made landfall and the havoc it wreaked on its path, the minister said the department had issued five flood alerts, including four alerts from 8 am on December 1 to 2.45 am on December 2, regarding the heavy inflow to the Sathanur Reservoir from upstream of the river and its tributaries following a heavy downpour due to the cyclone.

After the water level reached the safety storage limit of 117.50 ft, the officials judiciously released water from the reservoir to avert any major destruction downstream, he said.

The catchment area of the Thenpennai River and its tributaries had received a total of 170.60 cm of rainfall since the cyclone made landfall in a short span of time. It is unprecedented, Duraimurugan said and catalogued that the quantity of water discharged started at 19,500 cusecs from 6 am on Sunday, increasing to 25,600 cusecs by 8 am, 31,555 cusecs by 9 am, and further increased to 32,000 cusecs from 10 am on the same day. The quantity of water discharged further increased to 63,000 cusecs from noon (Dec 1), and the water released downstream from Sathanur further increased to 1.06 lakh cusecs at 1 pm on the same day.

Since the discharge from Krishnagiri Dam, Vaniyar Dam, and Pambar Dam increased rapidly, in addition to the floodwater from the Kallar River, it brought a heavy inflow to Sathanur. So, the officials, following the Compendium of Rules of Water Regulation, released 1.30 lakh cusecs at 2 am on Dec 2, the minister added. From 3 am, 1.68 lakh cusecs of water were discharged. After issuing the fifth flood alert, he said the department discharged 1.80 lakh cusecs of water.