Takapuna beach is often used to sell Auckland as the world's third most liveable city.
However, it was contaminated so badly last summer that it was deemed unswimmable 30 percent of the time.
Auckland Mayor Phil Goff told The AM Show it's been this way for far too long.
"We like to regard ourselves as clean, green, 100 percent pure, but actually that hasn't been an accurate reflection of Auckland since about 1905.
"It's a problem that's been in the 'too hard' basket, now the council has taken it out and put more funding into it."
Mr Goff told said the council will contribute $1.1 billion to clean up Auckland's beaches.
"We're going to put [the money] into making sure that birth right for our kids and grandkids, so they will be able to swim in our local beaches."
He said it's a big problem, but one that can be fixed.
"We can sort it out. For a start we've got to build a billion dollar central interceptor so that we can cope with the growth of the city and we can cut by up to 90% the wastewater overflows into the harbour that happens every time it rains.
"It takes a while to build, but we'll start construction. It'll take four or five years to get in place."
Mr Goff said this is not a problem with growth, but one that has existed since the western isthmus was built up and storm water was connected to wastewater.
"Every time it rains and there's a flood of water off the roofs all over the western isthmus area, it goes into the wastewater line and it overflows the wastewater 70 times a year.
"It's been around like that since the early 20th century. No we're saying 'this has got to be a priority'."
Mr Goff said the issues with faeces in Takapuna beach is not because of storm water, but because of a broken line.
"We've got poo in the water, that's not good enough.
"There are different causes in different places, but all of those things need to be addressed with priority and resources. We've now got the resources, we're going to get on and do it."
Beaches across Auckland were tested for water quality from November 1 2017 to April 30 2018.
In testing, beaches are graded either green, amber or red to indicate risk of infection. Red indicates a high risk, amber means low to moderate and green means a negligible risk.
Only two beaches from the 84 tested were given a green rating all summer long - Bethells Beach and North Piha.
Anchor Bay, Cheltenham, Devonport, Goat Island, Kendall Bay, Omaha and Tawharanui were all also deemed to "show evidence of consistently high water quality" but Safeswim says further testing is needed.
The beaches of the Manukau Harbour had some of the most consistently poor results, though Auckland Council says it has successfully remove all sewage water inputs into the area and most waste in the water is now from bird populations.
Other beaches still affected by sewer discharge include Pt Chevalier, Meola Reef, Cox's Bay, Herne Bay, Home Bay, St Marys Bay and Judges Bay.
Safeswim is a joint initiative between Auckland Council, Watercare, Surf Lifesaving Northern Region and the Auckland Regional Public Health Service.
Visit the website for up-to-date data on your local beach.