Why the Kaipara and not other harbours?
The Kaipara Harbour has the biggest tidal flows in New Zealand and is one of the largest harbours in the world. During spring tides the current in the Kaipara can exceed 9 kph (nearly five knots). The next four New Zealand harbours are Manukau, Hokianga, Whangarei and Waitemata. The Kaipara has over double the tidal flow of Manukau. Additional attractions of the Kaipara are the lack of commercial shipping, proximity to Auckland north of the isthmus, and relatively low leisure usage of the harbour mouth. The depth of the harbour mouth channel, where the turbines will be located, is an asset: neither too deep for access by divers if needed (31 mts to a maximum 52 mts), nor too shallow and therefore impacted by lack of water at low tide. The sandbar surrounding the mouth protects the project from oceanic waves.
