Parts of Ranganathittu Bird Sanctuary in Mandya were left inundated on Wednesday after water was released from the Krishnarajasagara reservoir.
The bird sanctuary, located on the banks of the Cauvery River, is home to as many as 60,000 migratory birds.
From Tuesday, visitors were stopped from entering the sanctuary. "Many islands in the sanctuary have been submerged and we have decided to close down operations,” said an official at the sanctuary.
Boat rides too have been stopped since August 9 as a precaution.
A flood alert was issued for areas along the banks of the River Cauvery after heavy rains forced the Karnataka government to release water from the Kabini and KRS reservoirs. In total, over 1,20,000 cusecs of water was released from the two reservoirs.
At 6 am on Wednesday morning, the Central Water Commission said that the water levels of the Cauvery in Mysuru district were flowing above high flood level (HFL).
At Chunchunkatte, the water level was recorded at 757.95ft while the HFL is at 757.45ft, while in T Narsipur the water level was 640.64ft while the HFL is 642.40.
On Tuesday, authorities decided to release close to 1 lakh cusecs of water from KRS alone to cope with the increasing inflow into the reservoir.
This caused a ripple effect in the downstream, low-lying areas of the reservoir, flooding several fields along the river as well as the Ranganathittu Bird Sanctuary.
The state has been witnessing heavy rainfall since the start of the week with the coastal areas being the most affected. The rains have led to landslides and inundation resulting in the suspension of train and bus services and disrupting normal life.