The authorities of Hirakud dam in Odisha's Sambalpur district on Sunday released the season's first floodwater to downstream of river Mahanadi, official sources said.
The water was released following a steady rise in the water level in the reservoir due to heavy rain in upstream of river Mahanadi.
The authorities of certain barrages in neighbouring Chhattisgarh have released floodwater which went to Hirakud reservoir taking its water level to 613 feet against the full reservoir level of 630 feet.
The officials said the floodwater was initially released from sluice gate number 7 of the dam at 9 am. Four more gates will be opened later in a phased manner.
The release of water will lead to a rise in the water level in river Mahanadi and its tributaries.
The Odisha government has issued an alert to the districts in the Mahanadi downstream and cautioned people not to venture into the river as flood water may reach soon.
There are 98 gates to release floodwater from Hirakud dam. While 64 are sluice gates, the rest 34 are crest gates. Each sluice gate can discharge 16,440 cusecs of water when the reservoir level is at 630 ft. Each crest gate can discharge 16,238 cusecs of water.
Meanwhile, the India Meteorological Department (IMD) has forecast rains across Odisha for four more days as a fresh low-pressure area is likely to be formed on July 24.