High storage level in major Idukki dams as new water year begins

With the arrival of the water year, 41 % storage was recorded in Idukki reservoir. | Photo Credit: JOMON PAMPAVALLEY

With the arrival of the new water year on June 1, the storage in major hydel dams, including Idukki, under the Kerala State Electricity Board’s (KSEB), is at a high level.

According to KSEB dam safety wing data, the storage level in Idukki reservoir on Saturday was 2,343.78 ft (40.82%) as against 2,332.56 ft (32%) on the same day last year.

The water year is considered from June 1 to November 30 every year.

“ But the early arrival of the monsoon resulted in the sudden increase of water in Idukki, including hydel dams. Within four days, the storage increased by over 9% in Idukki,” said the data from the dam safety wing.

The storage in major hydel dams on May 24 was 28% of the total storage. The storage rose to 42% on May 31. Within seven days, storage increased by over 14 % due to heavy rain, said an official.

According to sources, the high storage in hydel dams in the early days of the monsoon poses a threat to the 2018 model dam opening.

“The storage in Idukki dam on June 1, 2018, was 2,321 ft. In light of the August 2018 flood, this year’s water level in Idukki exceeded the storage limit by over 22 feet. From June 10 to June 30, the rule curve remains fixed at 2,373 feet. The rule curve in Edamalayar is 161 metres, and Banasurasagar is 975.36 metres until June 30,” said a KSEB dam safety wing official.

“The KSEB is now strictly following the rule curve. The shutters of the reservoirs will open when the water level reaches the rule curve. Considering the present storage level in Idukki, the water level is around 30 ft less than the rule curve level,” said the official.

Normally KSEB keeps a storage in hydel dams of around 20% in the last week of May. But the summer rains and the sudden arrival of the monsoon resulted in a sudden surge in the storage. “The dam safety wing and generation wing are closely monitoring the storage level in hydel dams,” said an official.

Meanwhile, the power generation in the Moolamattom power plant is at a moderate level, and the generation on Friday was 5.365 MU.

The storage levels in several key hydel dams on Tuesday were as follows: Pamba (44%), Sholayar (32%), Idamalayar (34%), Kundala (18%), Mattupetty (60%), Kuttiady (94%), Thariyode (32%), Anayirankal (29%), Ponmudi (91%), Neriamangalam (95%), Peringalkuthu (66%) and Lower Periyar (99%).

The water level in the Mullaperiyar reservoir on Saturday was 130 ft on Saturday. The maximum allowed level is fixed by the apex court at 142. ft.

Published - May 31, 2025 07:13 pm IST