The Cornwall Park Trust Board rejected having a huge new water mains pipe running beneath the park.
Watercare Services explained how it sought permission for the Hunua 4 water main to be under the park.
"Our preferred route for the pipeline was to include Cornwall Park but unfortunately we were unable to obtain access and land owner approval. As a result, the pipeline has to be laid through a number of residential streets," Watercare said.
Michael Ayrton, park director, said his board rejected the pipe for good reasons.
"Watercare approached us in February 2009 about the pipeline and along with local iwi, we discussed our concerns with them. We gave this a lot of consideration but on stepping back and looking at the totality of options we did not see the proposal for a pipeline as in the best interests of the park.
"The park already has to work around other historic infrastructure and as well as damaging the park's archaeological and geological features and a number of mature trees, the pipeline would have added to this constraint," Ayrton said.
But David Glen, who leases a board property, said the board had been unfair.
"It's another incidence of intransigence by the board with no care or responsibility shown to the local community. They would rather disrupt hundreds or thousands of local residents and commuters than a blade of grass be harmed in the process."