KOCHI: Quoting a Central Water Commission report, the Kerala State Electricity Board (KSEB) on Thursday informed the Kerala High Court that dams helped contain the 2018 floods. The report said Peerumedu rain gauge station in Idukki recorded 800mm rain from August 15 to 17, 2018, compared to Kerala’s annual precipitation of 3,000mm. If such rainfall happens across Kerala, water will rise to a height of 4.14m. Hence, it was clear the Idukki reservoir helped reduce the magnitude of Kerala floods in 2018. In August 2019, Idukki and Edamalayar dams together contained a huge inflow of water, reducing flooding in downstream areas of Periyar basin.
KSEB filed the report in response to a suo motu writ petition on the issue of rising water levels of dams and regulation of water in dams. In case of exigencies, the well-laid protocol for the large control releases from the reservoirs would be put in place for early warning and evacuation of the downstream population, said the board. The board operates 18 reservoirs in the state with a total storage capacity of 3,532mcm. As on June 1 2020, KSEB dams have only 23.9 per cent live storage. The KSEB had developed a Rule Curve for its four dams in 2018 having more than 200 mcm capacity. The Rule Curves have been approved by the Central Water Commission. They are prepared by qualified scientific experts analysing historic reservoir statistics.
KSEB submitted that regulation of water in dams is being done on a scientific basis considering various aspects like need and necessity. Further emergency action plan has been prepared for various reservoirs ensuring timely action downstream in the event of a flood. To avoid panic among the public, sufficient alert and warning systems have been put in place.Quoting previous events, the KSEB claimed that except during extreme rainfall events which are very rare, the chance of spill from the Idukki reservoir is remote.
