Miscreants allegedly lifted the two crest gates of the Chamaraja check dam built across River Kaveri and released the water into the canals, near Sakkere village, Chunchanakatte hobli, in K R Nagar taluk, Mysuru district on Sunday midnight.
Saligrama police have registered a case.
As the miscreants released water into the canals, around 7 ft water was wasted, stated the assistant executive engineer Gururaj in his complaint to the Saligrama police.
A team of engineers rushed to the spot and closed the crest gates.
CPI Krishnaraju of Saligrama police station has initiated a probe.