Significant earthworks going on up over the valley.
My bet is a new regional airport.
It’s nicely aligned with the prevailing northwesterlies, clear approach and departure routes with no significant obstructions and a control tower appears to be in the works.
A bit short, but if someone were to retrofit the Q300s with JATO packs, they shouldn’t be payload-limited to Auckland.
Arrestor hooks woud be useful too.
Not quite sure how they’ll handle southwesterly crosswind ops though…….