Notwithstanding the farmers’ protest in H.D. Kote against the release of water from the Kabini dam, which is close to attaining full reservoir level (FRL), no more water can be impounded without endangering the safety of the dam.
Though a section of farmers staged a protest against the release of water consequent to the Supreme Court’s directive, it is petering out, at least in H.D. Kote.
The water-level on Thursday was 2,281.38 feet against the FRL of 2,284 feet. It is normal practice to provide a buffer of about two feet when the monsoon is active in case of flash floods.
Hence, the authorities ensure that the outflow from the reservoir is more than the inflow if the catchment area of the river continues to receive heavy rain as it has during the last couple of days.
Sources told The Hindu that the gross storage capacity of the reservoir being relatively small, it tends to fill up quickly and the dam engineers are forced to open the crest gates to balance the inflow and the outflow so as to maintain the reservoir level at the optimum height which is two feet below the FRL. The gross storage capacity of the reservoir is 19.52 tmcft (thousand million cubic feet), and the live storage on Thursday was 17.7 tmcft.
The inflow during the last few days has increased steadily due to copious rain in the catchment area of the Kabini river in Wayanad district in neighbouring Kerala.
The inflow into the reservoir on Thursday was at the rate of 8,748 cusecs; the outflow was pegged at 9,000 cusecs.
An official pointed out that the crest gates of the Banasura Sagar dam, which is located upstream of the Kabini in Kerala, are opened during flash floods or when the inflow is high. Hence, the water-level in the Kabini reservoir is maintained at 2 feet below the FRL just in case there are flash floods. “If the water-level is maintained at the FRL, then the discharge from the Kabini will have to be stepped up to accommodate the corresponding inflow, and there is the possibility of flash floods wreaking havoc in downstream areas”, said sources.
Farmers have argued that the dam should be allowed to attain the FRL of 2,284 feet by impounding the inflow, but technical experts have ruled out any such possibility when the monsoon is active.
The water-level in the Krishnaraja Sagar (KRS) was 110.50 ft on Thursday against the FRL of 124.80 feet, while the reservoir level was 123.01 ft during the corresponding period last year. The inflow was 7,901 cusecs and the outflow was pegged at 2,583 cusecs and the live storage in the reservoir was 23.85 tmcft.
The water-level at Harangi was 2,857.41feet against the FRL of 2,859 feet and the inflow was at the rate of 1,427 cusecs, outflow was a mere 500 cusecs and the live storage was 7.53 tmcft.
Keywords: Kabini reservoir