The man has been identified as 37-year-old Alvaro Roman of Caruthers.
Firefighters say a witness reported seeing a man going into the water around 8 p.m. Thursday at the Regional Sports Complex off Jensen and West.
About 40 to 50 minutes after the initial sighting, emergency dive teams found Roman and pulled him up from the bottom of the pond.
He died later at the hospital.
It's not yet known why Roman went into the water or what may have contributed to the apparent drowning.