Complex sentence: Proposals for a railway line on the west coast of the North Island predated proposals for a railway line from Wellington to the Wairarapa, but land-owning interests in the Wairarapa saw that the latter line was given higher priority.
Split into simpler sentences: Proposals for a railway line on the west coast of the North Island predated proposals for a railway line from Wellington to the Wairarapa region. However, land owning interests in the Wairarapa saw that the railway line from Wellington to the Wairarapa was given higher priority.