Cyclone Fengal: Dams let out surplus as Fengal fills up storage

CHENNAI: Surplus water from the Sathanur Reservoir in Tiruvannamalai district and four other reservoirs in Villupuram, Krishnagiri, and Dharmapuri districts has been discharged due to heavy downpours induced by cyclone Fengal in the catchment areas.

The Water Resources Department has also directed the release of inflows to reservoirs in Tiruvannamalai and Villupuram districts, as the storage capacity has breached the buffer storage limit. However, the situation in Vellore and other northern districts remains stable, with sufficient storage capacity. The cumulative water level of the state's 90 reservoirs stood at 171.491 tmc, accounting for 76.46% of the full storage capacity of 224.297 tmc.

The water levels in the reservoirs of Tiruvannamalai and Villupuram districts are being maintained two feet below their full reservoir capacity (FRC) for safety, and the inflows to these reservoirs have been discharged downstream, as officials remain uncertain about what the slow-moving cyclone may bring in the coming days.

Officials also reported that 19,500 cusecs are being discharged from the Sathanur Reservoir, the state's fifth-largest reservoir with full reservoir storage (FRS) of 119 feet (73.21 tmc), into the downstream of the Thenpennai River from 4 p.m. on Sunday. The water level is being maintained at 118.05 ft (71.08 tmc), and rainfall in the vicinity recorded 108 mm between 6 a.m. and 4 p.m.

The water levels have also exceeded the buffer storage capacity in the Krishnagiri Reservoir (52 ft) and the Pambar Reservoir (19.60 ft), both located upstream of the Sathanur Reservoir. According to officials, a total of 3,345 cusecs have been discharged from the Pambar Dam and 436 cusecs from the Krishnagiri Dam, citing the 4 pm status.

Additionally, 1,125 cusecs have been released from Vaniyar Reservoir (65.27 ft) in Dharmapuri district, which was built across the Vanniyar River to maintain the water level at a safe storage limit. "We expect heavy rainfall on Monday and Tuesday due to the cyclone, which will help improve the storage levels in the district's Kasarigullihalla, Nagavathi, and Thoppair reservoirs. These reservoirs currently have less than 50% of their storage capacity, " said another official.

Following heavy inflows due to sharp showers in the catchment area of the Vidur Reservoir in Villupuram district on Saturday, the water level increased quickly to 30 feet, compared to its full storage capacity of 32 feet. "We have been discharging between 35,000 and 26,000 cusecs of water since early Sunday morning," said an official closely monitoring the reservoir's water levels.