The body of a 25-year-old man was found in the lake of the Los Medanos community college campus in Pittsburg on Monday.
There is no evidence that foul play was a factor in the unidentified man's death, college officials said in a statement.
The college did not say if the victim is a student, teacher, or someone with another connection to Los Medanos.
The death is being investigated by the Contra Costa Community College Police.
The county coroner will also perform an autopsy to determine the cause of death.
The area around the lake was temporarily closed off, but the campus is open as normal on Tuesday.