They later marched to the Vandiperiyar police station with a complaint.
"We have lost patience as this is creating untold miseries to us as it was around 3 a.m. that we realised water had entered our homes. There was no prior notice regarding it. Many of us have suffered a lot of damage and hence we have decided to protest," the agitators said.
The rising water was noticed by a few people taking bath at the Periyar river. They realised that there was a sudden increase of the water by around seven feet and raised an alarm.
On Wednesday, State Water Resources Minister Roshy Augustine had expressed his deep displeasure over the matter.
Consequent to the sudden opening of ten shutters out of the 13, by 60cms each, water gushed into the homes of numerous families living in the downstream of Periyar. Since it happened in the middle of the night, people were caught unawares.
"This is not expected of a government. I have already raised the issue with Chief Minister Pinarayi Vijayan who assured to take it up with the Tamil Nadu government. We will also approach the Supreme Court on this 'irresponsible behaviour," said Augustine.
The British-era masonry gravity dam is managed by the Tamil Nadu government although it is geographically situated in Kerala. The dam is at the centre of a row between the states, with Kerala keen on constructing a new dam while Tamil Nadu opposing the proposal.