Kerala plans to build a new dam to replace the 126-year-old Mullaperiyar dam in the Idukki district.

Mullaperiyar Dam

• It is a masonry gravity dam on the Periyar River in Kerala.
• It is located on the Cardamom Hills of the Western Ghats in Thekkady, Idukki District.
• It was constructed between 1887 and 1895 by John Pennycuick and also reached in an agreement to divert water eastwards to the Madras Presidency area.
• It has a height of 53.6 m (176 ft) from the foundation, and a length of 365.7 m (1,200 ft).

Operational issue

• The dam is located in Kerala but is operated and maintained by Tamil Nadu.
• The catchment area of the Mullaperiyar Dam itself lies entirely in Kerala and thus not an inter-State river.
• In November 2014, the water level hit 142 feet for first time in 35 years.
• The reservoir again hit the maximum limit of 142 feet in August 2018, following incessant rains in the state of Kerala.
• Indeed, the tendency to store water to almost the full level of reservoirs is becoming a norm among water managers across States.

The dispute: Control and safety of the dam

• Supreme court judgment came in February 2006, has allowed Tamil Nadu to raise the level of the dam to 152 ft (46 m) after strengthening it.
• Responding to it, the Mullaperiyar dam was declared an ‘endangered’ scheduled dam by the Kerala Government under the disputed Kerala Irrigation and Water Conservation (Amendment) Act, 2006.
• For Tamil Nadu, the Mullaperiyar dam and the diverted Periyar waters act as a lifeline for Theni, Madurai, Sivaganga, Dindigul and Ramnad districts.
• Tamil Nadu has insisted on exercising the unfettered colonial rights to control the dam and its waters, based on the 1886 lease agreement.

Rule of Curve issue

• A rule curve or rule level specifies the storage or empty space to be maintained in a reservoir during different times of the year.
• It decides the fluctuating storage levels in a reservoir.
• The gate opening schedule of a dam is based on the rule curve. It is part of the “core safety” mechanism in a dam.
• The TN government often blames Kerala for delaying the finalization of the rule curve.

UPSC 2022 countdown has begun! Get your personal guidance plan now! (Click here)

Get an IAS/IPS ranker as your 1: 1 personal mentor for UPSC 2024

Attend Now