Due to heavy rain, Water at Mullaperiyar dam in Kerala’s Idukki district is inching towards the permissible level of 142 ft. This dam is always a contagious issue between Kerala and Tamil Nadu and settles by Supreme Court in 2014. Supreme Court had allowed Tamil Nadu to increase the water level from 136 ft to 142 ft.

History of dispute:

• The Mullaperiyar Dam was constructed by the British during 1887-1895 across Periyar River in the then Travancore state (now Kerala) territory. The dam, with full reservoir level of 152 ft. provides for diversion of water from the reservoir through a tunnel to Vaigai basin in Tamil Nadu for irrigation benefits.
• A 999-year lease was made, and accordingly, the Tamil Nadu government has been operating the dam. The Periyar power station in TN produces hydro-electric power from these waters and distributes that electricity in the state
• The dam is one of the oldest dam in service in the world, at 105 years. The average life-span of a well-built and well-designed dam is considered to be 50-60 years by experts. When the British built the dam, they expected its life span to be around 2,000 years.

The Mullaperiyar Dam was made using old technology, and not based on the modern parameters for design of dams. In this case, much of the building material used in the construction has been leached out, by wear and tear.

• But then again, in 1930s, Tamil Nadu engineers bored 80 holes in the dam and injected 40 tonne of cement solution to plug seepage. Again in 1933, grouting technology was used to strengthen the dam. In 1960, 502 tonne of cement solution was injected. All this was done without any outside prodding
• Safety issue: After a few minor earthquakes in 1979 in regions surrounding the dam, security issues were raised over its security. Since then, both the Kerala and TN governments have been at loggerheads over the security issue.
• Later, experts from Indian Institute of Technology also examined the dam, and mentioned that the dam will not withstand an earthquake.
• Stand of Kerala Govt: The Kerala government's contention is that in case the dam breaks, the three dams downstream -- Idukki, Cheruthoni and Kolamavu – will not be able to withhold the pressure, which will put the lives of 3.5 million people in the state.
• Stand of Tamil Nadu Govt: On the other hand, the TN government maintains that if the Mullaperiyar is demolished, it will create water scarcity in five districts of the state, leading to a draught in the region.
• In 2006, Supreme court allowed Tamil Nadu to increase the water level from 136 ft to 152 ft which was objected by Kerala government. Kerala passed a law the Kerala Irrigation and Water Conservation (Amendment) Act, 2006, to prevent the neighboring State (TN) from raising the water level beyond 136 feet.(because this dam is in Kerala)
• Then this matter again went to supreme court. In ,2014 Supreme Court had allowed Tamil Nadu to increase the water level from 136 ft to 142 ft.