The Fresno County Sheriff's Office responded to a water rescue call around 5:30 p.m. Saturday along Highway 99 between Avenue 7 and Herndon Avenue.
Friends of 47-year-old Eric Torres reported that he was swimming when he disappeared.
The Sheriff's helicopter assisted in the search and directed firefighters to his location.
Firefighters then jumped in to get Torres out of the water and quickly provided life-saving efforts.
He was taken to a hospital where he later died.
Officials say Torres did not know how to swim and was not wearing a life jacket.