A Three Rivers Filtration Plant worker spotted his body tangled in a logjam on the north side of the dam.
IN said in a tweet that it was "saddened" to learn about Hardy's death.
The Fort Wayne Police Department, the Indiana Department of Natural Resources and the Allen County Coroner's Office are continuing their investigation of Hardy's death.
The Bills sent their condolences to the Hardy family on Thursday.
The former Indiana University star was drafted in the second round of the 2008 National Football League draft by the Bills.
The former Hoosiers star was a first-team All-Big Ten selection and Biletnikoff Award semi-finalist in 2007, a season that saw him set a new school record with 16 touchdowns. He had almost 2,800 yards and scored 36 touchdowns. After that season, he had become Indiana's all-time receiving leader in touchdowns, yards, and receptions.
Hardy was arrested in 2014 for attacking several police officers, but was found mentally incompetent to stand trial.
Hardy was a standout high school athlete growing up in IN, playing football and basketball at Elmhurst High School. His professional career didn't last very long, but he had his shot and took every chance with graciousness and appreciation.