Waitematā Harbour is the main access by sea to Auckland, New Zealand. For this reason it is often referred to as Auckland Harbour, despite the fact that it is one of two harbours adjoining the city. The harbour forms the northern and eastern coasts of the Auckland isthmus and is crossed by the Auckland Harbour Bridge. It is matched on the southern side of the city by the shallower waters of the Manukau Harbour. With an area of 70 square miles (180 km²), it connects the city’s main port and the Auckland waterfront to the Hauraki Gulf and the Pacific Ocean. It is sheltered from Pacific storms by Auckland’s North Shore, Rangitoto Island, and Waiheke Island.
The harbour is an arm of the Hauraki Gulf, extending west for eighteen kilometres from the end of the Rangitoto Channel. Its entrance is between North Head and Bastion Point in the south. The westernmost ends of the harbour extend past Whenuapai in the northwest, and to Te Atatū in the west, as well as forming the estuarial arm known as the Whau River in the southwest. The northern shore of the harbour consists of North Shore. North Shore suburbs located closest to the shoreline include Birkenhead, Northcote and Devonport (west to east). On the southern side of the harbour is Auckland CBD and the Auckland waterfront, and coastal suburbs such as Mission Bay, Parnell, Herne Bay and Point Chevalier (east to west), the latter of which lies on a short triangular peninsula jutting into the harbour.
While the harbour has numerous beaches popular for swimming, the older-style “combined sewers” in several surrounding western suburbs dump contaminated wastewater overflows into the harbour on approximately 52 heavy-rain days a year, leading to regular health warnings at popular swimming beaches, until the outfalls have dispersed again. A major new project, the Central Interceptor, starting 2019, is to reduce these outfalls by about 80% once completed around 2024.
