Mullaperiyar dam Controversy

The Mullaperiyar Dam was constructed by the British during 1887-1895 across Periyar River in the then Travancore state (now Kerala) territory. During the rule of the British in India a 999-year lease was made and accordingly, the Government of Tamil Nadu has been operating the dam.
The Periyar National Park is located around the backwaters of this dam. The dam was built by the British under the supervision of Benny Cook.  The dam’s purpose was to divert the waters of the west-flowing Periyar River eastwards, since it caused widespread floods in the Travancore region, by constructing a masonry dam and diverting the water from the reservoir by way of a tunnel across the watershed and the Western Ghats to the rain shadow region of the Theni Sivaganga District and Ramanathapuram districts of Tamil Nadu.
The lease provided the British the rights over “all the waters” of the Mullaperiyar and its catchments, for an annual rent of Rs. 40,000. About 60,000 ha in Theni, Madurai, Sivaganga, Ramanathapuram, and Dindigul districts in present day Tamil Nadu were intended as beneficiaries of irrigation waters from Mullaperiyar. Water is brought through a 1.6 km long tunnel till the Tamil Nadu-Kerala border and then flows through open canals to Churuliyar River which feeds the Vaigai dam in Tamil Nadu. From there a network of canals take the water to the fields.
The dam is one of the oldest dams 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. It 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. Thus 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. The experts from Indian Institute of Technology also examined the dam, and mentioned that the dam will not withstand an earthquake.
It has become the bone of contention between Kerala and Tamil Nadu.
Since 1970, Kerala has argued that the dam having outlived its life of 50 years is unsafe to maintain water at 46.3 metres—the full reservoir level—and it should be restricted to 41.45 metres. 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 danger in the state.  In 1979, the Central Water Commission (CWC)— the premier government agency dealing with dam safety—was asked to look into the matter; it suggested reduction of water level to 41.45 metres as an emergency measure along with other measures to strengthen the dam. Tamil Nadu agreed to this limit. Another committee headed by the then CWC chairperson B K Mittal was appointed in 2001 to look into the matter. It stated that the reservoir level be raised to 43.28 metres, after the strengthening measures were implemented. This was to be on an interim basis, and later reservoir levels could go up to the original level of 46.3 metres.
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 drought in the region.
In 1998, all Mullaperiyar-related cases were transferred to the Supreme Court which, in its order of February 2006, observed that the dispute is not a ‘water dispute’. It allowed raising the reservoir level to 43.28 metres and directed Tamil Nadu to carry out the strengthening measures suggested by CWC, and restrained Kerala from causing any obstruction.
In July 2009, the Kerala government proposed the building of a new dam, 1,300 feet downstream of the present Mullaperiyar reservoir, which can assure the safety of the people of Kerala from the existing high-risk structure. In 2010 Tamil Nadu rejected the idea of constructing the new dam over the Periyar River.
Finally in 2010 the Supreme Court appointed former Chief Justice of India A.S. Anand as the chairperson of a techno-legal panel formed to examine the strength and capacity of the more than a century old Mullaperiyar dam in Kerala.
Recently the 141-member house of Kerala unanimously passed a resolution that the central government should sanction a new dam to replace the leaking, masonry Mullaperiyar in Idukki district.
This is the third unanimous resolution passed by the Kerala assembly demanding a new dam. The first was passed in 1993 when K. Karunakaran of the Congress was the Chief Minister and the next came in 2009 when V.S. Achuthanandan of the CPI-M was heading the state government.
Kerala is worried that a strong earthquake might damage the dam and cause widespread destruction. It is seeking a new dam and has offered to fund and build it, but Tamil Nadu does not agree. Experts from Kerala side say if a quake strikes and the dam is damaged, over four million people and their property in districts of Idukki, Kottayam, Alappuzha, Ernakulam and parts of Thrissur would be washed away.
Whereas Tamil Nadu wants the dam’s storage capacity to be increased by raising the dam height from 136 feet (41.5 metre) to 142 feet (43 metre) as the state’s irrigation needs have shot up.
Mullaperiyar issue has sown the seeds of mutual distrust between people on either side of the 116-year-old dam.