It was the first time in a decade that Mullaperiyar dam featured in the Budget Speech of a Tamil Nadu finance minister.

In his first Budget Speech on Wednesday, Tamil Nadu finance minister N Marie Wilson said that the Vijay government would "pursue the raising of the Mullai Periyar Dam water level." The Supreme Court has allowed Tamil Nadu to raise the level to 142 feet. Now, the Vijay government wants the storage levels even higher.

Kerala's water resources minister, after consultations with Chief Minister V D Satheesan, has hit back. "Under no circumstances will Kerala approve of Tamil Nadu's declaration that it will increase the height of the Mullaperiyar dam," Mons Joseph said on Wednesday. He reiterated that Kerala wanted the existing dam decommissioned and a new dam constructed in its place. Kerala's Mullaperiyar strategy is developed around the theme 'water for Tamil Nadu, safety for Kerala'.

The Kerala water resources minister said that Tamil Nadu had no authority to increase the water level beyond 142 ft at a time when concerns about the safety of the 131-year-old dam had intensified. "We register our unequivocal objection to this arbitrary declaration that has not taken into consideration even the fundamental parameters laid down by the Supreme Court always," the minister said, and added: "Tamil Nadu has still not undertaken the dam safety audit it has to complete before December 31 this year."

He said Kerala would officially communicate its objections to the Tamil Nadu government.

On August 5, the water level in Mullaperiyar was 119.5 ft. Last year same time, it was 134.15 ft. The dam is situated in Kerala (on the Periyar river in Thekkady, Idukki district) but is operated by Tamil Nadu. Mullaperiyar is the main source of water for large swathes of agricultural lands in the rain shadow regions of Theni, Madurai, Dindigul, Sivagangai and Ramanathapuram.

While the antiquity of the dam worries Kerala, Tamil Nadu sees the dam as a lifeline. Occasional inter-state disputes have arisen from this differing perceptions about the dam. Recently, K Sivarajan was removed as the Kerala's representative from the five-member Comprehensive Dam Safety Evaluation Committee (CDSEC), constituted to inspect the Mullaperiyar dam, without consulting with Kerala. After Kerala's strong objections, former engineer-in-chief and special secretary of Odisha's Department of Water Resources has now been appointed in Sivarajan's place.

Last time when a Tamil Nadu Budget Speech mentioned 'Mullai Periyar', it was on February 16, 2016, when J Jayalalithaa was Tamil Nadu Chief Minister. Then, finance minister O Panneerselvan glorified the increase in the water storage level in the dam to 142 feet as a "towering achievement" of Jayalalithaa.

It was two years ago, in May 2014, the Supreme Court ruled that the water level in the dam can be increased from 136 ft to 142 ft.

The Supreme Court order had triggered widespread concerns in Kerala, prompting Kerala Congress leader P J Joseph to sound an apocalyptic warning that a dam break could wash away most of Idukki.