Hokianga's community is fighting to stop raw sewage from entering the harbour, with campaigners calling it "culturally abhorrent".
Wastewater from four sites ends up in the Hokianga Harbour, which is considered a taonga.
When it rains heavily, the water is barely treated, but it's not just the environmental damage causing concern. Campaigners say the cultural impact is just as devastating.
"It needs to stop. It needs to stop. It's not necessary to discharge human waste of that nature - to water anymore," said Dallas King, Hokianga hapū kaikōrero (spokesperson for Hokianga hapū).
"Technology has advanced."
Wastewater plants at Ōpononi, Rāwene, Kohukohu and Kaikohe all discharge into the harbour at Hokianga.
It travels down waterways including the Waiarohia Stream.
"From the turning of the high tide, for three hours after on the outgoing tide, you will never catch any locals here," King told Newshub.
"Because we know that's when wastewater is being discharged from the wastewater treatment plant up there.
"Often we will see literal raw sewage coming down here."
But it's not just visually offensive, it's a cultural outrage too.
Another name for the harbour is Te Hokianga Nui a Kupe - because according to some kōrero, it's here that Kupe first landed on these islands we call home.
Kupe's wife Kura Marotini is said to have come up with the name Aotearoa for the first time..
That's another reason why wastewater management is of such importance to local iwi.
"It's culturally abhorrent," said Moko Tepania, mayor of the Far North/Muriwhenua.
And now, Tepania is backing the call for change.
"[We're] looking at alternative options which are better for our environment, culturally safer for our people," he told Newshub.
"So I really need central Government to step up with an alternative, because the status quo is not working."
The existing wastewater infrastructure uses filtering pools that can overflow in heavy rains.
In the case of Hokianga, water retention rates can mean sewage is stuck in the inlet for months before being washed out to sea.
"Singapore, Switzerland, France, the state of Mississippi… All around the world we can see examples of how technology has advanced so much," said King.
"I'm always proud as a New Zealander of the world, and the leading things we've been able to do in this country, across so many different things," Tepania told Newshub.
"But when it comes to those really core important things, like wastewater treatment, why are we still stuck in a mindset from when our grandparents were young children? And still looking at those sorts of options. It's to not be afraid to try something new.
"Because heck what we're doing right now is not working for us."
"The thing, the place, the icon that we derive our sense of identity from is also receiving thousands of cubic metres of human waste every day," King said.
"That's the impact."
It's an impact that's tainting the very origins of this nation.
