State Ministers R Duraikannu and Kamaraj were among those present when water was released from Grand Anicut.
Officials said 4,750 cusecs of water each from Cauvery and Vennar rivers were released.
PWD officials said the water release would be monitored round-the-clock.
In Erode, senior Minister K A Sengottaiyan inaugurated the water release at Lower Bhavani Project reservoir to enable irrigation of about 1.70 lakh acres of land in the district.
The Minister appealed to the farmers to use the water judiciously.