Idukki dam

Idukki dam

Subject – Geography

Context – With predictions by the India Meteorological Department (IMD) of a fresh bout of heavy rainfall in Kerala, as a precautionary measure, water was released from the Idukki reservoir.

Concept –

• The Idukki Dam is a double curvature Arch dam constructed across the Periyar River in a narrow gorge between two granite hills locally known as Kuravan and Kurathi in Mariyapuram village in Idukki District in Kerala, India.
• This dam was constructed along with two other dams at Cheruthoni and Kulamavu.
• Together, the three dams and Two saddle dams, Kulamavu Saddle Dam (Near Junction) and Kulamavu Saddle Dam (Right Bank) have created an artificial lake that is 60 km2 (23 sq mi) in area.
  • The stored water is used to produce electricity at the Moolamattom Power house, which is located inside nearby rocky caves.
• Idukki Dam is 168.91 m (554.2 ft) tall, constructed between the two mountains – Kuravanmala and Kuravathimala.
• This is the second time in three years that water has been released from the reservoir, the largest in the state and one of the highest arch dams in Asia.
• Since the reservoir itself does not have shutters, two sluice gates of the Cheruthoni dam, part of the reservoir, were opened by 50 cm to release 100 cumecs of water.
• When the shutters are opened, water will first reach the Cheruthoniriver through the spillway and join the Periyar river at Vellakayam.
• Subsequently, the water will travel through areas like Thadiyambad and Karimban, followed by Chelachuvadu, Keerithodu and Pambla forest areas to reach the Lower Periyar dam.
• The water will travel through Neriamangalam, Bhoothathankettu and Idamalayar dams to reach Ernakulam district. In anticipation of the opening of the Idukki reservoir, shutters of the Bhoothathankettu and Idamalayar dams had already been opened for smooth flow of water.
• By Tuesday evening, around 4 pm, the water is expected to flow through Periyar and its tributaries by panchayats adjoining Aluva town like Keezhmad and Chengamanad and finally join the Arabian Sea.
• The decision to open the shutters of the Cheruthoni dam, as well as the Idamalayar and Pamba dams, was taken by a high-level committee appointed by the state government to look into the technical aspects of the water level in the dams and the impact it would have on settlements alongside the rivers.
• The Cheruthoni dam shutters were last opened in 2018 during the “once-in-a-century” floods that year. There was major criticism that the dam shutters were opened quite late and in haste without giving adequate warnings to the people.

Dams in Kerala –