Kochi: Authorities have asked residents on the banks of Periyar river to stay vigilant as two shutters of the Idamalayar dam were raised on Tuesday.

The Idamalayar shutters were raised by 50 cm to release 50 cubic metres per second (cumec). The water from the dam will first reach Bhoothathankettu and then flow towards airport area. 

The outflow from the dam will be increased to 100 cumecs by noon, Ernakulam Collector Dr Renu Raj said.

Idamalayar dam is located at Ennakkal between Ayyampuzha and Bhoothathankettu in Kerala's Ernakulam district.

The water level in Idukki and Mullaperiyar dams in Kerala has not come down even after lifting more shutters. In fact, the inflow to the reservoirs of these dams is increasing following the heavy rainfall in the catchment areas.

Mullaperiyar dam

Three shutters of the Mullaperiyar dam were raised further. Presently, all the 13 shutters of the dam have been raised to release 9,237 cusecs of water per second.

Water level in Mullaperiyar has also exceeded the rule curve now and there are concerns in Kerala that Tamil Nadu authorities – who are in charge of the dam – would release more water into the Periyar River. In view of this possibility, Kerala has asked Tamil Nadu to stick to the rule curve.

Idukki dam

Meanwhile, authorities will increase the volume of water being released from Idukki Dam on Tuesday. The water level in Idukki Dam is 2,387 feet now and the rate of water flowing out will be increased from 300 to 350 cusecs per second. Five shutters have been lifted here. With water flowing to the Periyar River from Mullaperiyar Dam, houses located in areas such as Manchumala, Aattoram, Kadassikadavu and Karuppupalam were flooded.

The Idukki reservoir consists of two dams, the Arch dam and the Cheruthoni dam and the shutters of Cheruthoni dam were opened for the first time in 26 years in 2018, to mitigate the worst flood faced by the state in a century. The water level at Periyar river, where the water from these dams flow into are slowly increasing, district authorities said. Currently the water level is at 2.335 m. The flood warning will be issued at 2.50m. It will cross the danger level when the water level reaches 3.76 m, district authorities said, adding that, the people residing along the banks of the river should remain vigilant.

Other dams

The shutters of Malampuzha Dam has been raised from 55 cm to 80 cm.

The authorities have also banned traffic along Mukkai-Nilampathy Road after the water swelled considerably in the Mukkai River.

At Kanjirapuzha Dam also, the shutters have been lifted from 80 cm to one m.

The valve of Siruvani Dam is now open by 1.70 m. It was 1.50 m till Monday. At Chulliyar Dam, a spillway would be opened on Tuesday as the water level is a mere 1.5 feet below the maximum.

In Pathanamthitta district, the Kakki-Anathodu Dam and Pamba Dam under the Sabarigiri Project are already open. The outflow of water from Kakki-Anathodu Dam is 70 cubic m per second and from Pamba Dam 25 cubic m per second, following which the water level in the Pamba River is expected to rise.

Similarly, the Banasura Sagar dam in Wayanad has also been opened and the water level has gone up to 774.35 m. The authorities have opened two shutters by 10 cm.

On Monday, Kerala Chief Minister Pinarayi Vijayan had asked the people to remain vigilant as major dams across the State have been opened and the water level in the rivers was likely to rise. Vijayan had said that the state government has taken measures to evacuate people from areas where the water level is likely to rise but asked everyone to remain cautious as the water inflow to the dams and reservoirs are still strong due to rains in the eastern part of Kerala. He had said that the water was being released in a controlled manner in strict adherence to the rule curve.

Relief camps

The authorities have arranged 11 relief camps in Palakkad district where 323 people have been relocated from their homes. Heavy rainfall is still reported from the hilly areas of Palakkad, including Attapady.

(1 cusec is one cubic foot of water flow per second. It translates into 28.32 litres of water per second.)