The boil water notice was issued after 'raw' (untreated) water from the Ross Creek reservoir got into the main water supply yesterday.
The reservoir was being drained for refurbishment work, and it was thought that the pipe being used for the operation fed into a stream.
"Unfortunately it turned out that valve vented water from the reservoir into some pipework that all of our paperwork insists was shut down 30 years ago and actually led into the city water supply," said Dunedin Civil Defence controller Sue Bidrose.
The council started receiving complaints about dirty water last night, but considered it was a result of cast iron pipes.
It wasn't until more complaints came in this morning that they realised their mistake and shut down the pipe at about 9.30am.
The affected area includes 1,712 residential and 826 commercial properties.
Residents have been told to boil water after untreated water entered the public supply.
Source: 1 NEWS
A US reporter has thrown Donald Trump's well-worn accusation that the media spread "fake news" back in his face in a combative exchange at the White House.
The altercation was brought about by CNN's Jim Acosta when he asked President Trump, during a media briefing on China's intellectual property laws, why it had taken him two days to directly condemn the deadly violence from white supremacists in Charlottesville over the weekend.
"Mr President, could you explain why you did not condemn those hate groups by name over the weekend?" Mr Acosta asked.
The Washington Examiner reports that President Trump's reply "they've been condemned, they've been condemned" referred to a statement he made yesterday to the media, in which he refused to take reporter's questions.
Mr Acosta's follow up on why a press conference was not being held at this briefing either elicited a terse reply from President Trump as he walked away.
"We had a press conference, we just had a press conference," President Trump said.
Mr Acosta countered "can we ask you some more questions", to which President Trump replied:
"It doesn't bother me at all, but I like real news, not fake news. You're fake news."
But Mr Acosta refused to take President Trump's typical fall back accusation, immediately declaring: "Mr President, haven't you spread a lot of fake news yourself sir?"