On Thursday, the Kerala Government told the Supreme Court to consider decommissioning the 126-year-old Mullaiperiyar Dam owing to its age and low storage capacity. This has come after a number of netizens trended the #DecommissionMullaiperiyarDam on various social media platforms. What was the reason for the issue getting blown up in the past few days? We explain it here.
What is the prominence of this dam? Who built it and when?
The dam was constructed in 1895, during the British rule, to solve the water crisis that Madurai (then part of the Madras Presidency) faced. The Vaigai river that flows through that region was small enough to provide enough water and hence the dam was constructed to divert a portion of water from Kerala's Periyar river (which joins the Arabian Sea). The dam was designed by British engineer John Pennycuick and is bound between the present states of Kerala and Tamil Nadu through a 999-year lease. It was signed by the then Maharaja of Travancore, Visakham Thirunal Rama Varma (Idukki, where the dam is situated was part of Travancore) and the British Secretary of State for India for Periyar Irrigation Works. The lease agreement was signed by the Dewan of Travancore V Ram Iyengar and State Secretary of Madras State JC Hannington.
For how long have people been concerned about the safety of the dam?
It all began in 1979 after the Morbi Dam flood in Gujarat killed around 15,000 people. Post this, studies were conducted by the Kerala government to inspect the condition of the dam. Those suggested that the structure would not withstand an earthquake above magnitude 6 on the Richter scale. Following this, Tamil Nadu had lowered the water level of the dam by almost 16 feet.
Did it solve the issue?
No. The two states have been conflicting over the issue since 2006, the year in which Mullaiperiyar was declared an 'endangered' scheduled dam by the Kerala Government. This was after the Supreme Court permitted Tamil Nadu to raise the level of the dam to 152 ft (46 m) after strengthening it. Kerala since challenged the validity of the lease. In 2014, the SC struck down the 2006 judgment and said that the water level cannot be increased beyond 136 feet. It also proposed constructing a new dam.
What happened in 2021?
Kerala has been facing constant floods since 2018, killing and affecting a large number of people. At the same time, a few weeks back, a UN report on threats possessed by ageing dams across the world stated that Mullaiperiyar Dam situated in a seismically active area has major structural flaws and 3.5 million people are at risk if the 100+ years old dam were to fail. Following this, petitions were filed in the Supreme Court to examine the situation and the top court asked both states to act seriously as 'people's lives are at risk'.
What is the current situation?
On Thursday, Tamil Nadu decided to raise a few shutters of the dam. Residents of a few villages around the area have been evacuated after water was released from the dam to maintain the water levels of Idukki Dam. However, people have been asked by both states to not worry.
What exactly did the Kerala government tell the court?
To quote the government document, it read, "The consequences of any failure of this dam could be extremely catastrophic and beyond human imagination. The apprehensions of the Govt of Kerala regarding the life and safety of more than 30 lakh people of 5 districts residing downstream of the dam has to be given due importance and consideration."
