Ngāti Kahungunu says its litigation of its regional council is not a good example of what a partnership should look like.
The tribe took Hawke's Bay Regional Council to the Environment Court over fears officials would allow contaminants to run into the Heretaunga and Ruataniwhā aquifers.
The iwi won the case, meaning the council can not abandon its responsibility to maintain water quality.
The chair of the tribe Ngahiwi Tomoana said he was disappointed the iwi had to end up in court when they would prefer to sit at the decision-making table with local authorities.
In evidence, Mr Tomoana likened the aquifer to the womb of Papatūānuku, or mother earth.
He said if the water of the aquifer is allowed to be degraded, then the water of the womb becomes degraded.
Mr Tomoana went on to say:
"This water is used by the whole community for municipal water supplies and our local horticultural and agricultural industries. Degradation is not an option".
Marei Apatu also gave evidence for hapū:
"Ngāti Hori and Ngāti Hawea are not adverse to any action it deems necessary to protect our taonga, our whenua and our wai, and it is our duty as Māori and kaitiaki to do whatever it takes to hold true to our values, beliefs and rituals in order we pass these taonga on in good condition for the next generation to come."
Hawke's Bay Regional Council released a short statement in response to the court's finding.
It said the decision provided some challenges for both the council and land users over how to handle water resources in the Heretaunga Plains.
The council's strategic development group manager Helen Codlin added:
"We believe the decision is less relevant to the Tukituki Catchment because of the development of the specific Plan Change for that catchment."