Rangitoto Channel Explained

Rangitoto Channel
Location:Auckland Region, New Zealand
Islands:Duder Spit, Rangitoto Island
Coords:-36.803°N 174.817°W
Rivers:Wairau Creek
Oceans:Hauraki Gulf, Pacific Ocean
Countries:New Zealand
Settlements:Belmont, Devonport, Hauraki, Milford, Narrow Neck, Takapuna
Pushpin Map:Auckland
Pushpin Label Position:right
Pushpin Map Caption:Location within the Auckland Region
Pushpin Map Alt:Location within the Auckland Region

The Rangitoto Channel is an area of the Hauraki Gulf in the Auckland Region of New Zealand's North Island. The channel is north-east of the Waitematā Harbour, and is located between the North Shore and Rangitoto Island. The channel's traditional Ngāi Tai name is Maori: Te Awanui o Peretū, and is an important deep water shipping channel to reach the Ports of Auckland.

Geography

The Rangitoto Channel is located in Auckland, between the North Shore and Rangitoto Island.[1] During the Last Glacial Maximum (known locally as the Ōtira Glaciation), the area was a valley for the Waitematā River, which when sea levels rose between 12,000 and 7,000 years ago became the Waitematā Harbour.[2] The channel is an important stretch of water as it is the only deep water approach to Auckland Port for large ships such as container cargo ships and passenger cruise liners.[3]

History

The traditional Ngāi Tai name for the Rangitoto Channel is Maori: Te Awanui o Peretū or "The Great Channel of Peretū", named after an early ancestor in Tāmaki Makaurau, who lived at Narrow Neck and kept a kākā parrot reserve on Rangitoto Island.[4] The channel was visited by the Tainui migratory canoe after arriving in Tāmaki Makaurau.[5] [6]

During the Russian scare of the 1880s, coastal fortifications were built along the Rangitoto Channel, including a fort at North Head and a military camp, Fort Cautley, at Narrow Neck. These were upgraded during World War II, and further gun emplacements were constructed at Castor Bay and other East Coast Bays areas to the north.[7]

The channel was last dredged from a depth of 11.2m to 12.5m in a two-stage process in 2004. The first stage involved the mechanical excavation of hard rock. Blasting was not required. This was followed by the removal of softer material. All dredged material was used in the reclamation at Fergusson wharf.[8] [9]

Notes and References

  1. Web site: Rangitoto Channel . New Zealand Gazetteer . Land Information New Zealand. 29 June 2023.
  2. Web site: Estuary origins . National Institute of Water and Atmospheric Research. 3 November 2021.
  3. Land Information New Zealand Marine chart NZ532
  4. Cultural Values Assessment Report to New Zealand Transport Agency for Northern Corridor Improvements Project (NCI) . . . April 2016 . 30 June 2023.
  5. North Shore Heritage - Thematic Review Report Volume 1 . Heritage Consultancy Services . . 1 July 2011 . 978-1-927169-21-6 . 29 June 2023.
  6. Book: Willis, Jenny. Early History of East Coast Bays. Second. 2018. 6.
  7. 102-103, 111.
  8. Rock removed from shipping lane
  9. Rangitoto Shipping Lane Dredging & Wharf Reclamation