The independent panel of commissioners appointed by the Grey District and West Coast Regional councils on the application released their decision this week.
It follows an earlier rejection two years ago of the Tiga proposal by a joint panel of the two councils.
Tiga proposes a 12-year operation.
The 186-page decision with another 32 pages of extensive conditions includes the associated processing plant and associated support facilities on about 2ha of the site.
It will result in "a minimum average" of 50 extra truck movements on the scenic Coast Road (State Highway 6).
The decision notes "an innovative water management system" by Tiga to enable their operation in a coastal site with "a delicate ecological setting".
A key matter was the argument about functional need for the proposed site under the national environmental standards for freshwater as Tiga wants their mine within the 100m wetland setback of the Canoe Creek coastal lagoon.
The regional council’s own planning specialist Michael Durand controversially argued during the hearings this was not a valid reason.
The commissioners said the argument Tiga did not have a functional need to encroach into the 100m setback was "misguided".
"We consider the constraints and characteristics influencing Tiga’s mine design created a ‘functional need’ to operate within the 100m setback," the decision said.
The impact of mine lighting on the nocturnal flying petrel was the other key consideration.
The Department of Conservation said consent should be declined because of the risk despite a range of mitigation proposals by the applicant.
"The panel does not see how any further measures beyond the offered conditions, such as declining consent, will meaningfully contribute to protecting the Westland Petrel from population-level cumulative effects arising from existing threats and those that foreseeably could arise in the existing environment," the decision says.
Tiga has also confirmed heavy mineral concentrate will be trucked on the Coast Rd to either Rapahoe or Stillwater for rail loading.
"We do not consider that the maximum of five additional ... haulage truck movements per hour, six days a week, coupled with the daily morning and evening minibus movements for shift workers, will exacerbate that risk to such a degree that would warrant consent being declined."
The land is used as dairy run-off by Nikau Farm Limited.
Tiga is targeting ilmenite (titanium-iron oxide) and garnet.
The decision notes the coastal strip for the intended mine is in "a mosaic of natural and cultural resources and activities, including ‘a complex network of waterways’ and surrounded by significant natural heritage supporting ‘a complex array of ecological relationships’,".
A residents group input had positively impacted the conditions Tiga were prepared to endorse, the commissioners said.
There had also been "a high degree of agreement" among the two council’s technical experts, that the proposal’s effects could be "managed appropriately by conditions".
- LDR is local body journalism co-funded by RNZ and NZ On Air.
By Brendon McMahon
