M-sand for constructing new Mullaperiyar dam

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THIRUVANANTHAPURAM:Pointing a finger towards the absolute burnout of natural resources in the state, the State Government has deci..

THIRUVANANTHAPURAM:Pointing a finger towards the absolute burnout of natural resources in the state, the State Government has decided to go in for M-sand for the construction of the new Mullaperiyar Dam. This has been stated in the feasibility report of the new dam that was submitted to the Empowered Committee of the Supreme Court on Monday. "The materials required for the construction of the concrete gravity dam are available locally. Considering the present shortage of natural sand, it is proposed to use crushed/manufactured sand (Msand),' says the report.
The new structure is proposed as a combination of main dam and a saddle dam on the left flank, requiring a humongous volume of sand for construction. While the structure which will gobble up such huge amounts of sand may damn one river, it may damn many other rivers of the state.

It is this realisation that has pushed the State Government to think in terms of alternative construction materials such as the Msand that is available in the neighbourhood of the dam. A quarry for broken stones and crushed sand has been identified at Chenkara, located at a distance of 35 km from the site of the dam. "The samples from this quarry were tested at the Kerala Engineering Research Institute (KERI), Peechi, and found to be satisfactory,' says the 33page feasibility report.

Cement and steel are to be bought locally and transported to the site of construction.

One important proposal is to construct river sluices/scour sluices, which is not present now. "The sluices of appropriate sizes at suitable locations in the main dam will release water for maintaining the environmental flow during lean months and for flushing out the accumulated silt during the flood seasons,' says the feasibility report. There shall not be any change in the level of the reservoir at 136 feet but it will have more storage capacity. The water diversion structures such as channels and tunnels will also remain unchanged.

However, a Comprehensive Environmental Impact Assessment (CEIA) is necessary for evaluating the impact of the proposed construction of the new dam on the environment and ecology of the area.

The new dam is expected to come up in four years. On completion of the new dam, the existing old dam will have to be decommissioned partially or fully for enabling the present reservoir to spread up to the new dam.