The car skidded on Kaikorai Valley Rd near Burnside and landed in Kaikorai Stream about 7am.
Fire and Emergency New Zealand Senior Station Office Ant O’Neill said the ute was "fully submerged" in the stream.
"The young driver was very lucky to escape."
"And also if you see emergency vehicles at an incident slow down and take care going through the scene.
"We’ve had multiple cars come though the scene today and they’ve nearly hit our fire truck and other responding vehicles."
The first major frost of the winter caused several accidents in the city this morning, prompting warnings for motorists to take more time and care on the roads.
Moments later, while the drivers were exchanging details, two more cars collided behind the incident.
No-one was injured in either crash, and another grit truck was sent out soon after.
A fourth crash happened in Glen Rd, near Harwood St, where a car slid on ice and hit a power pole about 8.15am.
Again, no-one was injured and a grit truck was sent to the scene.
Sergeant Matt Lee said icy conditions would become more prevalent in the coming months, and he too urged drivers to take more care on frosty mornings.
"Drive to the conditions, and try to build in some more time because it will take you longer to get there.
"This is the time when you are most likely to encounter black ice on the roads, so be careful in the mornings."
The coldest place in the southern region this morning was Alexandra, which recorded -4.6°C.
MetService meteorologist John Law said temperatures dropped to -4.4°C in Mosgiel just before dawn, and the mercury in Dunedin city dropped to about 2°C.
However, in the valley suburbs, the temperatures could also have been sub-zero, he said.
"They are so-called frost hollows that you sometimes get, where that cold air sinks down into those valleys."
Mr Law said there would be more cloud cover over the next few days, which would keep the frosts at bay, but the long-term forecast showed-high pressure systems with clear skies returning in the coming weeks.
"I think we’re going to find our temperatures will be on the cold side, so we will find more frosts."
