Normal life was on Monday hit due to a dawn-to-dusk hartal called at Idukki in Kearal by the ruling Congress-led United Democratic Front and Opposition Left Democratic Front protesting Tamil Nadu's stand over Mullaperiyar issue and Centre's "reluctance" to mediate on it.
Cutting across political lines, activists of various parties and resistance groups protested over delay in endorsing their demand of building a new dam at Mullaperiyar, over which the state has been locked in a tiff with neighbouring Tamil Nadu.
Protesters blocked roads linking Kerala and Tamil Nadu at Kumali and other entry points, although no violence was reported from anywhere, police said.
Meanwhile, political lobbying over the issue has also gained momentum with state Water Resources Minister P J Joseph and Revenue Minister Thiruvanchur Radhakrishnan rushing to New Delhi to discuss the matter with senior cabinet ministers and central leaders of Congress.
The Left MPs are also planning to raise the issue in Parliament to force the national parties to spell out their views on the vexed issue.
Increase in inflow into the reservoir touching slightly above the maximum permissible storage level of 136 feet has heightened fears about the safety of the dam among people in the area and adjoining districts.
Kerala had been persistently arguing that the dam posed a dire threat to lives and properties of over 3 million people in Idukki, Kottayam, Ernakulam, Alappuzha and Pathanamthitta districts.
As an urgent measure, the state wants the water level to be lowered to 120 feet.