It is not avery good image - but I suspect you have Paraserianthes lophantha - a very common weedy tree in Auckland and one whose seed is well dispersed and often present in urban seed banks (especially where soil has been bought in). I don't think its Acacia dealbata but to be sure (in both cases) you'd need to have a better set of images including bark, adult foliage, inflorescences and capsules.