"This dam will bring more large-scale industrial dairy farms to Hawke's Bay driven by debt and shareholders to exploit the land, the rivers, the cows and the workers," he said.
"The regional council is meant to look after and manage our rivers, wetlands and aquifers," he said. "Instead they are subsidising pollution."
The dam plan is a "prime example" into an intensification model New Zealand cannot sustain, he said.
The current Government drive to triple agri-food exports by 2025 meant producing more cheap industrial food commodities, which he said is a "blind allegiance to a failing economic strategy".
"We in New Zealand need to decide whether we want to produce industrial ingredients or real food with proud provenance," he said.