Napier people fear waterways in the city could be at a point of "no return" if nothing is done to stop their destruction.
The Ahuriri Estuary, or Te-Whanganui-a-Orotū, lies on the edge of Napier around its seaside.
Photo: RNZ / Tom Kitchin
Investigations have found there is 400 times the safe guidelines for some nutrients in the water, potentially leading to algae bloom which could cause serious degradation.
After dozens of spills in the water recently, including one of almost 1000 litres of hydrochloric acid, people are demanding change.
The Ahuriri Estuary (Te-Whanganui-a-Orotū) sits on the edge of Napier and is the largest estuary between Wellington and Bay of Plenty.