A lawyer for the Hawke's Bay Regional Council has told the High Court a Board of Inquiry made the right decision in granting resource consents for the Ruataniwha dam.
Three environmental groups have gone to the High Court in Wellington, seeking to have the consents overturned.
Lawyers for the groups raised concerns that the dam development and other works would lead to greater levels of nitrates leaching into the area's soils.
They also questioned the amount of influence the council exerted on the Board of Inquiry after it released its draft decision.
Council lawyer Trevor Robinson told the court the board operated within the statutory framework and the process it adopted was not unfair.
He said the Freshwater National Policy Statement did not require the board to be satisfied that its decision would ensure nitrogen limits would be achieved.
The case was expected to end tomorrow.