Watching water gush from the main into a ditch and down Stuart St, a Dunedin City Council employee was heard yelling to Fulton Hogan workers: "That's the one main we told you not to hit!''
Council networks contract manager William Clifford said the main was damaged about 9.30am by contractors carrying out trenching work for Aurora Energy.
Later in the day, he said work was taking longer than expected and some network issues meant about 200 to 300 properties might have been without water for a couple of hours yesterday afternoon.
Properties affected were in the Highgate area from Roslyn to Belleknowes.
Water should have been restored yesterday, but further shutdowns might be needed today while the pipe was being repaired, he said.