The Kerala government on Monday filed an affidavit in Supreme Court in the Mullaperiyar Dam case seeking the reconsidering of the fixing of Upper Rule level at 142 feet as formulated by Tamil Nadu on September 20 in view of heavy rainfall in Kerala and the consequent surge in reservoir levels, and sought that a new dam be built downstream.
The affidavit has been filed by Alex Varghese, Chief Engineer, Inter-State Waters, Irrigation Department, Government of Kerala. According to the Affidavit, the Periyar Lease Deed was executed between the Maharaja of Travancore and the Secretary of State in Council on 29.10.1886 conveying all lands that fall within the contour line of 155 ft “measured from the deepest point of the bed” of the Periyar river at the site of the construction of Mullaperiyar dam for a period of 999 years. Mullaperiyar dam is a composite gravity dam built during the period 1886-1895.
Subsequent to press reports in the late seventies, of large-scale leakages in the dam, the then Chairman, Central Water Commission, Dr K. C. Thomas, inspected the Mullaperiyar dam at the instance of the Government of Kerala in 1979. The condition of the dam was found to be not satisfactory, and after discussions with Kerala and Tamil Nadu officials, he proposed a set of emergency, medium- and long-term measures for repair/strengthening the dam structure and also recommended maintaining the water level at 136 ft. However, these strengthening measures do not add any improvement to the strength of the dam, the affidavit said.
The state government states that the Central Government constituted the Supervisory Committee vide notification dated 01.07.2014 inter alia to keep close watch on the safety of the Mullaperiyar dam. The Supervisory Committee is headed by the Chief Engineer, Dam Safety Organisation of the Central Water Commission. The Additional Chief Secretary of Kerala and the Principal Secretary of Tamil Nadu, Public Works Department are the members.
The affidavit emphasizes that the alarming rise in the water level of Mullaperiyar dam due to heavy rains which occurred in the catchment of Mullaperiyar dam from October 16, 2021 and the concerns of Kerala on the safety of the dam and the people living downstream of the dam were placed before the Supreme Court on October 25, 2021 for the regulation of water level at Mullaperiyar dam. The Supreme Court directed all the authorities to interact immediately on an urgent basis and the Supervisory Committee to take a firm decision about the maximum water level to be maintained in the dam.
In compliance with the Supreme Court order dated 25.10.2021, a Supervisory Committee meeting was convened by the Chairman, Supervisory Committee & Chief Engineer, DSO, CWC on 26.10.2021 to discuss the regulation of water level in Mullaperiyar dam. The State of Kerala made a detailed presentation on the entire concerns of Kerala. Kerala had categorically specified that post 2018 floods, the dynamics of rainfall and pattern has changed tremendously. Also Kerala provided details of 3 instances of extreme surge of water level in a single day occurred in the past 4 years (2018 to 2021). Kerala has not concurred with the Rule Curve proposal placed by Government of Tamil Nadu and stressed upon to maintain the then water level in the reservoir to 137 feet in view of upcoming North East Monsoon. Kerala also requested the Chairman, Supervisory Committee to incorporate the details raised in the letter dated 26.10.2021 and to issue a modified minutes at the earliest before the submission to the Supreme Court.
The Affidavit averred that Kerala was witnessing heavy intense floods due to the incessant rains over the month of October 2021. Residents were cut off in many parts of Kerala as the rain started to intensify from October 15, 2021. Idukki district was one of the worst affected areas which received heavy rainfall. Torrential rain pummeled Southern and Central Kerala districts triggering landslides and floods which left 20 dead and havoc across Pathanamthitta, Kottayam and Idukki districts. The heavy rains triggered landslides and swelled many rivers across the State. Roads were swept away, houses were damaged and trees uprooted. Several villages in hilly areas were cut off.
It is submitted that in the backdrop of past history of sudden upsurges of water level records in the Mullaperiyar reservoir, the State is very vigilant in closely monitoring the water levels of the Mullaperiyar dam. The alerts of IMD are viewed constantly and necessary arrangements are being taken by the State to maintain the water level in the reservoir so as to overcome the flash floods in the downstream stretches.
The Kerala government alleged that the water level in the Mullaperiyar dam rises more rapidly if there is continuous heavy rain for one- or two-days during monsoon season. Hence, in view of the recent incidents of heavy rainfall in the State of Kerala and specifically in the catchment of the Mullaperiyar dam (particularly in 2018 and 2019) and consequent sudden surge in the reservoir levels, projected change in rainfall patterns due to climatic change and its impact on floods the fixing of Upper Rule level at 142 feet as formulated by Tamil Nadu on September 20 may be reconsidered.
The affidavit states that no amount of rejuvenation by any means can perpetuate the 126-year-old deteriorated Mullaperiyar dam. There is a limit to the number of years one can keep dams in service through maintenance and strengthening measures. All over the world, citizens, Governments and organizations have begun to review the safety of their dams as per modern standards and design criteria.
The State of Kerala states that 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 informed the court that the rule curve prepared by Tamil Nadu in consultation with CWC is required to be reconsidered by the Supervisory Committee in line with the suggestion given by the Kerala
Considering the ageing of the dam and as the dam is situated in the Seismic Zone III, Kerala asked the court to issue directions to the State of Tamil Nadu to implement a comprehensive instrumentation plan for the dam.
It is pertinent to note that the Apex Court on October 28 while asking Kerala and Tamil Nadu to abide by the decision taken by the Supervisory Committee regarding the appropriate water level in Mullaperiyar dam had adjourned the hearing in the case till November 11.
The bench was hearing two writ petitions seeking urgent directions to restrict the water level in Mullaperiyar dam, which is being managed by the State of Tamil Nadu for drawing water to its districts.