Manukau Harbour

Manukau Harbour is the second largest natural harbour in New Zealand by area. It is located to the southwest of the Auckland isthmus, and opens out into the Tasman Sea.GeographyThe harbour mouth is between the northern head located at the southern end of the Waitakere Ranges and South Head at the end of the long Awhitu Peninsula reaching up from close to the mouth of the Waikato River. The mouth is only 1800 metres wide, but after a nine kilometre channel it opens up into a roughly square basin 20 kilometres in width. The harbour has a water surface area of 394 square kilometres. There is a tidal variation of up to 4 metres, a very substantial change, especially since the harbour, being silted up with almost 10 million years of sedimentation, is rather shallow itself.Because of the large harbour area and narrow mouth between the Manukau Heads, tidal flow is rapid and a bar at the mouth makes navigating in or out of the harbour dangerous. New Zealand's most tragic shipwreck occurred on the bar in 1863 when HMS Orpheus ran aground in clear weather with a loss of 189 lives. For this reason, along with the harbour's shallowness, it is not Auckland's favoured port, and, with only one short wharf, the facilities at Onehunga are tiny compared to the other Ports of Auckland facilities on the Waitemata Harbour along the northeast of the isthmus.