Iwi authority Ngati Kahungunu is celebrating an Environment Court decision it says is a victory over Hawke's Bay Regional Council's attempts to reduce water-quality standard provisions for the region's aquifers.

At a hearing in December, Ngati Kahungunu Iwi Incorporated challenged the council's attempts to change two objectives related to groundwater quality as part of a change to the regional resource management plan.

One of the changes proposed by the council was the removal of an objective in the plan which states: "No degradation of existing groundwater quality in the Heretaunga Plains and Ruataniwha Plains aquifer systems." The council argued the "absolute" wording of the objective was impossible to achieve and water quality could be better protected by addressing catchment-specific issues elsewhere in the plan.

In a decision on Friday, the Environment Court sided with Ngati Kahungunu, saying its bid to retain the objectives was in keeping with the provisions of the Resource Management Act.


"To not aspire and attempt to at least maintain the quality of water abdicates the functions of a regional council," Judge Craig Thompson and commissioners Kevin Prime and Anne Leijnen said in their judgment.

Ngati Kahungunu chairman Ngahiwi Tomoana said the decision was pleasing after the iwi had spent more than $100,000 and months preparing the challenge.

"Some of our whanau say we should be spending [iwi resources] on education and economic development issues but we've also got to maintain the [environmental] standards that have been set, so it's about juggling resources," he said.

"[This decision] is the convergence of the law with our lore, and these things are usually at odds, but they've converged quite strongly in the judgment. It's very encouraging for us."

The council's strategic development group manager, Helen Codlin, said the council was still reviewing the judgment and its implications.