Kerala Power Minister M.M. Mani has said the Cheruthoni shutters will be opened when the water level in the Idukki reservoir touches 2,398 feet.
People will be alerted when the water level hits 2,397 feet and a trial run would be conducted when it reaches 2,398 feet.
"The trial run will be held irrespective of whether the intensity of the rain increases or wanes," the minister told reporters after an assessment meeting at Idukki collectorate on Thursday. The middle shutter will be opened 50 cm for four hours.
The Kerala government had on Wednesday said water from the Idukki dam has to be released in phases. Many people are heading towards Cheruthoni dam, the shutters of which are set to be opened after 26 years. However, authorities have imposed restrictions and police personnel stopped people from visiting the dam.
After the water level touched 2,395 feet on Monday night, just eight feet short of the full level, an orange alert was issued. Authorities have asked all those living along the banks of Periyar River to stay alert. The full reservoir level of the dam is 2,403 feet.
Orange alert implies that the present condition has the capacity to significantly impact the people in the affected areas. The Kerala State Disaster Management Authority (KSDMA), however, said an orange alert does not mean that shutter would be opened any time now. The final red alert would be issued when the water level touches 2,399 feet.