Matthew Johnson, 19, of Caldwell, was driving west on Idaho 55 in a 1996 Mazda 626 at about 6 a.m. Thursday when the car went off the right shoulder and over a canal.
The wreck took play west of the intersection of Karcher and Midway roads in Canyon County.
Johnson was taken by ambulance to Saint Alphonsus Medical Center in Nampa, according to the Idaho State Police. He was wearing a seat belt and the car's airbag deployed, police said.
The ISP is investigating the crash.