A hopeful developer argues its 1000-house development next to Okura marine reserve would be better for the environment than Auckland Council's alternative.

Okura Holdings Limited, a subsidiary of Todd Property, has appeared in the Environment Court to appeal Auckland Council's 2016 decision to reject a recommendation for the Unitary Plan to include moving the rural-urban boundary to make way for the massive development.

On Tuesday, Okura Holdings' lawyer Sue Simons told the court the council's alternative of 29 lots deemed "countryside living" would become a "millionaire's playground".

Artistic impression of development at Okura. With light green stripes to be housing and surrounding dark and mid colour ...

TODD PROPERTY/SUPPLIED

Artistic impression of development at Okura. With light green stripes to be housing and surrounding dark and mid colour greens to be public land/ extension of Long Bay Regional Park.

Simons said the countryside-living option would place no obligations on owners to protect or enhance the land and would shut out the public from the area, north of Auckland.

"This will become a millionaires' playground which can be looked on from afar by the rest of Auckland," she argued.

Okura Holdings argued it was addressing one of council's fundamental needs, housing.

Simons said the infrastructure requirements for development were already present in the area in the Long Bay development.

These included storm and wastewater infrastructure and the base for traffic infrastructure.

Simons acknowledged the site was sensitive but argued Okura Holdings had the capacity to develop the area without negatively affecting it.

In response to concerns around the potential amount of sedimentation running off the site into the marine reserve, Simons said, in the long-term, Okura Holdings' proposal would result in less sedimentation as a result of riparian planting and sediment controls, not present in the countryside living option.

She said potential heavy metal run-off could and would be dealt with by monitoring and risk mitigation.

A key part of Okura Holdings' argument touched on its proposal to include 55 hectares of public open space in the development. This would include a coastal walkway and planting and would act as an extension to the Long Bay Regional Park and Te Araroa trail, Simons said.

"While it is acknowledged that Auckland Council does not have unlimited funds to acquire reserves, to not explore options such as this ... is bewildering."

She asked the Environment Court to agree with the Unitary Plan Independent Hearings Panel and move the boundary. She said the site was an obvious location for urbanisation.

"It is backed by a willing developer with the means to develop and a history of positive outcomes."

The appeal started on September 18. The court had already heard from Auckland Council's counsel as well as from the Long Bay-Okura Great Park Society. Both argue the proposed urbanisation would negatively affect the area's unique values including wildlife and nearby marine reserve.