Millan Ruka, a spokesman for Te Uroiori; Te Parawhau; and Te Mahurehure ki Whatitiri hapu, said the hapu were devastated.
"Essentially our water is being stolen. Now it's finally signed and sealed because they have the consent to take the water and now they have the application to build the plant," he said.
Members of the public can make submissions to the council on Zodiac Holdings' application. Mr Ruka said hapu felt like "flies on the wall".
"We are devastated. We've been given the August 30 to respond. No resources, no one with RMA (Resource Management Act) experience. Absolutely nobody. I'm just a total layman myself," he said.
The plant would have a gross floor area of 3650sq m with a maximum height of 10m, sized to "meet the production efficiencies and resulting price competitiveness expected in a modern-day export based facility of this type", the application said.
In Simpson Grierson's advice to Zodiac Holdings, it said claims by iwi relating to ownership of the springs under the Treaty of Waitangi were not relevant to the land-use consent.
"Nobody owns the water but they will. They'll own it, put it in a bottle, and sell it. And you drain from our resource here," Mr Ruka said.
Hesaid 50 litres of water per second needed to flow into the spring to keep the levels up.
Mr Ruka said that flow already varied and was worried water supplies would deplete when Zodiac Holdings began operating.
"The sustainability of the springs has always been paramount. But we have always wanted our own economic benefit by way of tuna enhancement, propagation of watercress - that's just a small part of it."
In a letter from the New Zealand Transport Agency to Zodiac Holdings it said the plant was anticipated to generate up to 80 (40 in and 40 out) truck movements per day once operating at full capacity on the already busy State Highway 15.
This worried Mr Ruka.
"I've written plenty about it. We've already had trucks spinning out here and flipping up here and we have the school right there," Mr Ruka said.
The application said the facility would also enable Northport to further utilise its container-handling capability and the benefit to the port is also a benefit to Northland because Northport was partly owned by ratepayers.