A 19-year-old man is dead after his car plunged into Isabella Pond,Tuggeranong, on Saturday.

He is the third road fatality in the ACT this year.

Police say that at about 4.20pm a green Holden Commodore sedan was travelling north on Drakeford Drive when it drove between two bridges, plunging into Isabella Pond, where it was quickly completely submerged.

Emergency services responded and the sole occupant of the vehicle, the 19-year-old man, was found dead in the car.

Police want to speak to anyone who may have seen or have dash-cam footage of the green Holden Commodore travelling along Drakeford Drive before it left the roadway. Call 1800 333000, or via the Crime Stoppers ACT website.