Date:28/02/2006 URL: http://www.thehindu.com/2006/02/28/stories/2006022812150400.htm

Kerala - Thiruvananthapuram

Water level and safety aspects of a century-old dam

Special Correspondent

THIRUVANANTHAPURAM: The Mullaperiyar dam, known as Periyar dam in Tamil Nadu, was constructed by the erstwhile Madras Government between 1890 and 1895 on the strength of a lease deed executed by the Maharaja of erstwhile Travancore in 1886 in its favour.

The lease covered about 8,000 acres and the water flowing into it, besides 100 acres nearby for irrigation works. The period of lease was specified as 999 years. A supplementary agreement amending the deed was executed in 1970 between the Governments of Kerala and Tamil Nadu. Under this agreement, the lease rent on land was increased from Rs.5 to Rs.30 an acre. Tamil Nadu was given the right to produce electricity using the water for a rent of Rs.12 per kilo Watt year (kWy). (Rs.18 per kWy for generation in excess of 350 million units).

Though it was envisaged that the agreement would be reviewed every 30 years, the revision has not taken place so far.

Water from the reservoir irrigates paddy fields and farms in Ramanathapuram, Sivaganga, Virudhunagar, Madurai and Teni districts in Tamil Nadu.

The dam, having a length of 1,200 feet and a height of 176 feet, was made of uncoursed rubble masonry in lime mortar on the front and rear faces. Sandstone and lime surkhi mortar formed the rear. The full reservoir level is 152 feet.

Leakage of the dam has been reported from the Thirties and grouting and guniting had been done in 1935 and 1960 to plug the leaks.

The maximum water level was reduced from 155 feet to 152 feet in 1964 following a joint inspection by the Director of Central Water Commission and engineers of the two States.

In 1979, the chairman of the Central Water Commission inspected the dam. At an official meeting that followed, it was decided that the water level should be kept at 136 feet. Construction of additional spillways to check rise in water level and certain strengthening measures were proposed. These measures were completed only a decade later. In 1996-97, the Kerala Government appointed an expert committee and it reported that the strengthening measures were inadequate. Both Tamil Nadu and Kerala appointed technical committees to examine the safety of the dam following an inter-State Ministerial-level meeting in 1998. However, there was no unity of opinion between the two committees.

Following intervention by the Supreme Court, the Central Government convened a meeting of the Chief Ministers of the two States and officials in 2000. At the meeting its was decided to appoint an expert committee to study the safety aspects. The seven-member expert committee visited the dam in 2000 and submitted its report in 2003. The committee favoured the raising of the reservoir level to 145 feet with dissent note from the Kerala representative M.K. Parameswaran Nair.