The New Zealand Department of Conservation has removed the final roadblock to Crest Energy’s plans for a landmark 200MW tidal-power project in wreck-scattered waters off the North Island.

The department signed off last month on the NZ$600m ($450m) development, which is proposed for a treacherous expanse of the Tasman Sea outside Kaipara Harbour known as The Graveyard because it has claimed up to 110 ships.