SC to hear plea to reduce water level at Mullaperiyar + SSC_CGL?.ToString()?? SSC_CGL?.ToString()+" Current Affairs";

Why in the news?
The Supreme Court on December 6th fixed in January a detailed hearing of a petition seeking to bring down the permissible water level of the Mullaperiyar dam in Kerala from 142 ft to 120 ft to obviate the possibility of adam breach.
About the Mullaperiyar dam:
Mullaperiyar dam is situated at the confluence of the Mullayar and Periyar rivers. 
The dam is located entirely in Kerala.
It was built in the late 1800s in the princely state of Travancore (present-day Kerala) and given to British-ruled Madras Presidency on a 999-year lease in 1886.
The agreement granted full rights to the Tamil Nadu to construct irrigation projects on the land.
The dam was built to divert eastwards a part of the west-flowing Periyar river, to feed the arid areas of Tamil Nadu.
The dam stands at the height of 53.66 metres and 365.85 metres in length.
The dam is owned, operated and maintained by Tamil Nadu.
Tamil Nadu maintained it for several purposes, including irrigation, drinking water supply and hydro-power generation.
Situation after Independence:
After the independence, the Kerala government said that the earlier agreement signed between British Raj and Travancore was invalid and needed to be renewed.
As a result, the agreement was renewed in the 1970s. 
Tamil Nadu was given rights to the land and the water from the dam as well as the authority to develop hydro-power projects at the site.
Kerala received rent in return.
Origin of the Mullaperiyar Dam Dispute:
Safety concerns surfaced in 1979 after it was reported in the Kerala that a minor earthquake had caused cracks in the dam.
The Central Water Commission was asked to examine the structure and suggest ways to strengthen it. 
As an emergency measure, the commission recommended that the level of water stored in the reservoir be lowered to 136 feet from about 142 feet.
It held that the water level could be raised to the dam’s full capacity of 152 feet after the structure was strengthened.
This caused two divergent perspectives leading to the emergence of dispute between these two states:
Tamil Nadu claims that though it has undertaken periodic repairs on the dam, the Kerala government has not allowed it to raise the water level.
Kerala, on the other hand, contends it is not safe to raise the water level as Idukki district, where the dam is located, is earthquake-prone.
Supreme Court Judgement on Mullaperiyar Dam Conflict:
In 2006, the Supreme Court allowed the Tamil Nadu government to raise the water level to 142 feet, contending that the apprehensions raised by Kerala were baseless.
The Kerala government countered this with an amendment to the 2003 Kerala Irrigation and Water Conservation Act. 
The amendment classified the Mullaperiyar dam as endangered and restricted the level of water in it to 136 feet.
This amendment was declared unconstitutional by the SC in 2014.
In 2014, SC said that Kerala could not obstruct Tamil Nadu from raising the water level to 142 feet. 
To allay Kerala’s concerns, it directed that a three-member supervisory committee be set up to:
oversee the process of raising the water level, 
inspect the dam routinely, and 
look into the safety concerns.
What is the Dispute?
In late 1979, after the eruption of the controversy over the structural stability of the dam, it was decided at a tripartite meeting chaired by K. C. Thomas, the then Chairman of the Central Water Commission that the water level be lowered to 136 feet against the full reservoir level of 152 feet so that Tamil Nadu could take up strengthening measures.
In 2006 and 2014 the Supreme Court held that the water level be raised to 142 feet, up to which Tamil Nadu stored water even 2021.
The court’s judgment of 2014 also provided for the formation of the supervisory committee and the completion of the remaining work by Tamil Nadu.
But, there has been no end to litigation over the dam with Kerala witnessing landslides in recent years.
Though there had been no reports of landslides in the vicinity of the dam site, the events in other parts of the State led to a renewed campaign against the dam.
The Kerala government proposed that the existing dam be decommissioned and a fresh one be built
These options are not completely acceptable to Tamil Nadu which wants to complete the remaining strengthening work and restore the level to 152 feet.
Why is the Dam Safety Act?
About:
The Dam Safety Act, 2021 came into force in December 2021.
The act is aimed at addressing the long-felt need for addressing issues concerning the safety of major dams all over the country.
It provides for surveillance, inspection, operation, and maintenance of certain dams for prevention of disasters related to dam failure, apart from institutional mechanisms to ensure their safe functioning.
The Act covers those dams having a height of over 15m and between 10m and 15m with certain stipulations.
Create two National Institutions:
National Committee on Dam Safety (NCDS): It seeks to evolve dam safety policies and recommend necessary regulations, and the
National Dam Safety Authority (NDSA): It seeks to implement policies and address unresolved issues between the two States. The NDSA will be the regulatory body.
Create two State Level Institutions:
The legislation also envisages the formation of State Dam Safety Organisations and State Committees on Dam Safety.
Dam owners will be held responsible for the construction, operation, maintenance, and supervision of dams.
How does the Dam Safety Act Affect Mullaperiyar?
Since the act provides that the NDSA will perform the role of the State Dam Safety Organisation for a dam located in one State and used by another, the Mullaperiyar dam, strictly speaking, comes under the purview of the NDSA.
Besides, the Supreme Court, which has been hearing petition after petition after its judgment in 2014, mooted the idea of extending the powers of its supervisory committee to take over charge of the safety and maintenance of the structure.
What are the Key Highlights about Periyar River?
The Periyar River is the longest river in the state of Kerala with a length of 244 km.
It is also known as ‘Lifeline of Kerala’ as it is one of the few perennial rivers in the state.
Periyar River originates from Sivagiri hills of Western Ghats, in Tamil Nadu and flows through the Periyar National Park.
The main tributaries of Periyar are Muthirapuzha, Mullayar, Cheruthoni, Perinjankutti.