CHENNAI: Kerala’s proposal to build a new Mullaiperiyar dam in the downstream, to replace the existing 123-year-old dam, will spell disaster for Tamil Nadu if realised. Top TN officials, who went into a huddle on Wednesday, said the State would struggle to meet its irrigation and drinking water needs if the status quo changed.
Madurai, Theni, Dindigul, Sivaganga and Ramanathapuram districts depend on the Vaigai to meet drinking water and irrigation needs. The Vaigai gets a major feed from the Mullaiperiyar dam via a tunnel through the western ghats. If Kerala builds the new dam, as proposed, 1,200 feet below the existing dam, TN will no longer be able to enjoy its ‘current’ benefits.
Express accessed the pre-feasibility report (PFR) and letters exchanged between Kerala’s Irrigation department and the Union Environment Ministry in the last two months. Though Kerala claims, “It does not desire to deprive Tamil Nadu of Mullaperiyar waters... and will ensure continued supply of water to Tamil Nadu”, there is no explanation, technically, as to how it would do so.
In the 50-page PFR, Kerala says, “The present water diversion structures...will remain unchanged.... As such, the present arrangement of water diversion to TN will continue to function uninterruptedly during construction of the new dam and after its commissioning.”
However, the tunnel that supplies water to TN is at the 125-feet water level of the existing dam. PFR says the new dam will be built 1,200 ft below the existing dam. Maximum height of the main dam will be 174 feet. “How will Kerala explain this? TN will not get water if the existing dam is decommissioned and a new one is built,” a senior Public Works Department official said.
TN officials also rubbished the safety concerns raised by Kerala. “The dam is completely safe and repair works on the saddle dam can be finished if Kerala gives access,” said Sam Irwin, the dam’s Assistant Executive Engineer. Officials said attempts to get green clearance will be thwarted legally.
Officials of Dam Safety Directorate in Public Works Department (PWD) said Kerala government’s move to construct a new dam claiming that the existing Mullaiperiyar dam is unsafe, is ‘unfounded’.S Asokan, Chief Engineer (operations and maintenance), Dam Safety Directorate, told Express that Mullaiperiyar dam was completely safe and the structure has been strengthened considerably. “Work on the baby dam is being obstructed by Kerala authorities,” he said.
There is a Supreme Court order, which directed Kerala to permit Tamil Nadu to take up the work of re-laying the wearing coast on the top of the baby dam. Tamil Nadu is also permitted to clean the stilling basin to fill up the eroded pockets with Epoxy concrete as also to carry out rearming of the drainage holes in drainage galleries. “There is a sub-committee which exclusively monitors the safety and operations of the Mullaiperiyar dam on a monthly basis,” he said.
Sam Irwin, Assistant Executive Engineer, Mullaiperiyar dam, said there are certain additional works suggested by Central Water Commission (CWC) and they are under process. Retired PWD engineer Thirunavukkarasu said under the current agreement tax per acre is Rs 30 and for electricity generated in lower camp using Mullaiperiyar water, it is Rs 12 per kilowatt per hour. “Tamil Nadu uses the water and the land and paying Rs 2.5 lakh as tax per year for the whole land and Rs 7.5 lakh per year as a surcharge for the total amount of electricity generated to the Kerala government for the past 50 years. The validity of this agreement will end, if the old dam is decommissioned and the new one is constructed. Going by the pre-feasibility report of the proposed dam, there is no way Tamil Nadu would receive water,” he said.
In a letter addressed to the Secretary of the Union Environment Ministry on August 23 this year, KH Shamsudeen, Chief Engineer, Kerala Irrigation Department, said, “Despite the strengthening undertaken by Tamil Nadu, Mullaiperiyar dam has not gained adequate strength to function further. The dam has outlived its useful life and consequences of any failure could be catastrophic. It is imperative that this structure requires urgent decommissioning for discharging the responsibility of the State to protect the lives and properties of its citizens.”
Theni-based environmental activist Muru Maran said the issue is the original lease agreement that gave 8,000 acres for the reservoir and another 100 acres to construct the dam. But, after the water level was brought down from 152 ft to 142 ft, the water spread area of the reservoir has shrunk from 8,000 acres to less than 4,000 acres. “During the course of time, a lot of plantations and constructions have come-up in areas, which had water earlier. They are lobbying for decommissioning of existing dam,” he said and added that Centre is abetting it.
Records show this is not a new proposal. Kerala has been making futile attempts from as early as 1979. But the proposed construction was not pursued, though administrative sanction was accorded for conducting a detailed investigation for studying the feasibility of the new dam and a new Sub Division was exclusively formed for this purpose with headquarters at Kumili in 2007.
As the dam is to be located inside a wildlife sanctuary, permission from the National Wildlife Board (NWLB) is mandatory for carrying out any non-forestry activities. Meanwhile, the Kerala Assembly unanimously passed a resolution on July 24, 2009, for the construction of a new dam, but it was declared invalid by the SC.
CM asks PM to intervene
CM Edappadi K Palaniswami on Tuesday sought the intervention of PM Modi to withdraw the recommendation made for grant of ToR for Kerala’s proposal.