Midway Motors owner Chris Henderson said contractors had been doing maintenance on the water meters most of the day, but there had been a problem with one that ran under his property.
"We heard a horrific boom, ... a valve landed up on the roof, and there was a whole lot of water," he said.
He believed a valve had broken off the meter causing the "specialty water feature" over his business.
The water was still spouting an hour after they heard the noise, but one of the workers backed their truck over the leak to prevent it spraying over the roof of the building.
The maintenance team had been looking to find a valve to shut the water off.
They had been communicating with his business about the progress.
"These things happen. We just get on with it."
A Dunedin City Council spokesman said there had been complications turning off a valve while replacing a water meter at the business.
This had resulted in the burst water main.
The incident caused the loss of water supply to about 20 properties in the area, he said.
Contractors remained on-site to fix the issue and had restored water about 5.30pm.
