Shutters of the Idukki arch dam may not need to be opened just yet, with the catchment areas witnessing a substantial weakening of monsoon rain and inflows reducing to a trickle.
Water level in Kerala’s largest reservoir now stood at 2401.7 feet overnight on Sunday, merely 0.8 feet away from the threshold.
INFLOWS WEAKEN
Inflows are down to a trickle after the rains relented since Saturday, earning a much-needed respite for officials manning the three-dam structure.
The spillways of the Idukki reservoir are built into the Cheruthoni dam, located 1 km west to west of main arch dam. There are five shutters here, of which two are to be opened when required.
Cheruthoni joins the arch dam and the Kulamavu dam a little further away to hold back water creating an artificial lake of 60 sq km at a height of 2,300 km above sea level.
The water stored is used for generation of electricity at the Moolamattom power house, which is reputedly the biggest underground power station in the country.
OPENED TWICE
The full reservoir level is 2,403 feet at Idukki, but the impounded water will not be allowed to get to that level, according to the Kerala State Electricity Board, which owns and operates the dam.
The shutters have had to be opened twice in the past, but only during the northeast monsoon (October to December) on both occasions.
The first time was in 1981 when they were repeatedly opened and shut between October 29 and November 13. The second time was in 1992 when they were kept open for 12 days from October 12 to 23.
Water level touched the brim only when the storage built up during the southwest monsoon was augmented by the inflow received immediately afterwards following heavy downpour early in the northeast monsoon.
FIRST INSTANCE
For the first time, heavy rains during the June to September monsoon alone have been sufficient to fill up the dam almost to the brim, raising the possibility of opening of shutters.
The State government and the electricity board have been watching the situation closely and had sounded a warning to the district administrations of Idukki and Ernakulam.
But with rains receding, the shutters may not need to be engaged for at least for a couple of days unless the rains came in hard yet again.
K.K. Karappan Kutty, Chief Engineer (Dam Safety), is leading a team of officials keeping a vigil at the dam site.