The Kerala government made a strong pitch in the Supreme Court to decommission the 126-year-old “deteriorated” Mullaperiyar dam operated by Tamil Nadu and build a new one, saying climate change, erratic and heavy rainfall and floods make the spectre of catastrophe real and near.
Kerala’s affidavit coincides with a red alert issued in Chennai following torrential rains. The Chennai rains came in the heels of several days of downpour in Kerala.
The State also referred to the Uttarakhand flood, also known as the Chamoli disaster of February 2021, mainly attributed to the climate change in the environs of the Nanda Devi National Park, a UNESCO world heritage site.
“The only permanent solution for removing the eternal threat owing to the safety concerns of the 126-year-old existing dam in Mullaperiyar and for protecting the safety of the lakhs of people living in the downstream of Mullaperiyar dam, is to build a new dam in the downstream reaches of the existing Mullaperiyar dam,” the State, represented by advocate G. Prakash, said in an affidavit.
The suggestion dates back to 1979. Kerala had suggested it in meetings held with the Union Minister for Water Resources and the Chief Ministers of Kerala and Tamil Nadu. “But Tamil Nadu had not concurred with the proposal of new dam,” the affidavit noted.
Victoria dam decommissioning
The State referred to the decommissioning of another 19th century lime concrete structure, the Victoria dam in Australia, which was decommissioned following seepages.
“Authorities decided to decommission the dam in April 1990. In its place, a new Victoria dam has been constructed, which now supplies drinking water to the city of Perth,” Kerala pointed out.
The State urged the court to have the Supervisory Committee reconsider the peak value of upper rule level of 142 feet formulated by Tamil Nadu in consultation with the Central Water Commission (CWC).
If the water level at Mullaperiyar was kept at a higher level, releases from it would be affecting the already filled Idukki reservoir, it argued.
“A cascading failure of Mullaperiyar and Idukki will result in a catastrophe which is beyond imagination affecting the life and property of 50 lakh of people residing below the Idukki dam,” Kerala said.
In Seismic Zone III area
The ageing dam was situated in the Seismic Zone III area, it stated and urged the court to issue directions to Tamil Nadu to implement a “comprehensive instrumentation plan” for the dam.
The State reiterated it had made a detailed presentation to the Supervisory Committee on October 25 about the “tremendous” change in the “dynamics” and “pattern” of rainfall post the 2018 floods in the State .
Kerala had not concurred with the rule curve proposal placed by Tamil Nadu and stressed upon to maintain the then water level in the reservoir to 137 feet in view of the Northeast monsoon.
“The Government of Tamil Nadu have been constantly requested to take necessary action to increase the discharge through the spillways and through the tunnel so as to maintain the water level as per the rule level. Though Tamil Nadu officials have increased the discharge through the spillway, their efforts were not translating into maintaining the reservoir level at 138 feet on 31.10.2021 and the water level was maintained at 138.55 at 11.00 pm on 31.10.2021 which was above the upper Rule level proposed by Tamil Nadu and hence violated the directions of the Supreme Court,” Kerala alleged.
The court, in an interim order on October 28, ordered the States to abide by the water level notified by the Supervisory Committee.
The case is coming up for hearing before a Bench led by Justice A.M. Khanwilkar on November 11.
