As the country enters its peak swim season, some Aucklanders have been left risking their health with dozens of beaches deemed unswimmable.
Auckland Council says work is underway to clean its water but others say they're frustrated at how long it's taking.
One person at the beach today described the water as "really sludgy", prompting them to stay on the sand.
"It's a nice spot... so it would be nice if you could swim in it," another said.
A look at the council's SafeSwim website this morning showed more than 20 beaches in the region classified as red alert.
This happens when bacteria found in animal and human faeces is detected in the water.
It means people shouldn't be swimming.
Auckland Regional Public Health Service (ARPHS) medical officer Dr Jay Harrower said there could be "pretty unpleasant" consequences of a dip.
"There's potential likelihood you could get infected because of it, and that would be things like if you had an open sore, or an open wound, that could become infected," he told 1 NEWS.
"You could get infected through your eyes, ears, nose, and if you swallowed water you could get gastroenteritis so nausea, vomiting, diarrhea... pretty unpleasant."
Hobson Bay in Ōrākei is one of the worst contaminated.
Work is underway to make it swimmable, but some of that won't start until 2026.
In some cases, beaches just one kilometre apart have different alert levels.
This morning, people were advised not to swim at Little Manly but they could at Stanmore Bay.
"That beach may not have the same flushing effects and tidal and other effects as the beach adjoining to it," Auckland Council's Craig McIlroy says.
"But there might be a slight difference in timing between when one beach goes green and one beach stays red.
"Typically if the weather stays fine that'll change over a matter of a few hours and you'd expect both those beaches to be green unless there's been a specific issue identified in the network."
Ocean Swim organiser Scott Rice felt the effects of the city's water quality, having to cancel events last minute.
"With a country like ours in New Zealand, "clean green", it's not a good image and it's something I think needs to be a priority," he says.
McIlroy says it's an issue faced by "all urban communities in the world".
"Where the public should be pleased in Auckland is where we've got a problem, there's a massive amount of financial investment going towards resolving the problem at the moment," he says.
"You may be aware Auckland has a water quality targeted rate."