Judges Bay Beach has recently recorded a result of 1600 enterococci per 100ml. A beach deemed safe will have a sample reading of less than 140 enterococci per 100ml, while one deemed unsafe will have a reading of more than 280 enterococci per 100ml.
More than a third of the region's most popular spots have failed the tests since November - with at least 10 sites being so bad they prompted a red flag on the council's three-tier reporting system: meaning the erection of signs recommending no swimming.
A council spokeswoman yesterday said the signs erected at Judges Bay were a precautionary measure made to steer people away until further tests were taken.
"If they get two consecutive sample readings that are over 1000, then they'll start investigating as to the cause," she said. "It's not necessarily anything, but they have put up signs as a precaution."
The beach was given a $4.9 millon facelift last year, when sand was brought in to create an all-tide beach.
Warning signs went up at Judges Bay on Wednesday evening.
Auckland councillor Cameron Brewer said he spotted a council official erecting a public health warning sign just after 5pm.
Mr Brewer said: "I approached him and asked what it was all about. He told me that sewage was detected [on Tuesday] ... Let's just say we high-tailed it back to Remuera and had hot showers."
Danger in the water - to swim or not to swim?
- Laingholm Beach: 190 enterococci/ 100 ml (status: retest)
- Judges Bay: 1600 enterococci/ 100 ml (status: retest)
- Mission Bay: Safe
- Kohimarama: Safe
- Cockle Bay: Safe
- Okahu Bay: Safe
- Cox's Bay: Permanent health warning, unsafe
Auckland Council Website or 0800SAFESWIM Auckland councillor Cameron Brewer and daughter Lucy discuss the state of Judges Bay Beach with a council official.