Mangere Inlet is an arm of the Manukau Harbour, the southwestern of the two harbours of Auckland, New Zealand and itself an arm of the Tasman Sea. The inlet lies between the two cities of Auckland City and Manukau City and has a size of 6.6 km2 and a catchment of 34.5 km2, being considered to extend to just west of Onehunga. It is an environment highly modified by land reclamation and human uses, with the northern shoreline especially affected. However, the inlet also acts as a natural sedimentation sink, thus being especially at risk of contamination. It is surrounded by the suburbs of Te Papapa, Southdown, Westfield, Ōtāhuhu, Māngere East, Favona, and Māngere Bridge. The narrowest point on the Auckland isthmus is at Ōtāhuhu, where the coast of the Māngere Inlet is a mere 1200 m from the Otahuhu Creek, which ultimately feeds into the Hauraki Gulf. The Mangere Bridgecrosses the western end of the inlet where it joins the main body of the Manukau Harbour. At this point the inlet is about 750 m wide. The Waikaraka Cycleway also travels along the northern shoreline of the inlet. Ngarango Otainui Island is situated in the inlet at the eastern end near Ōtāhuhu.
History
is the location of one of the overland routes between the two harbours, where the Maori would beach their waka and drag them overland to the other coast, thus avoiding having to paddle around Cape Reinga. This made the area of immense strategic importance in both pre-European times and during the early years of European occupation. In the 1850s, after settlement by Europeans, the areas around the inlet had become the agricultural centre of Auckland. Later industrial expansion westwards from the new railway line at Westfield led to increasing discharges of contaminants into the inlet.
Environment
The inlet is highly man-modified, with three embayments at the inlets of historic streams having been lost along the northern shore, to a significant degree for use as landfills, and a loss of tidal inundation to the Hopua volcanic crater forming the Onehunga Basin further west. Ann’s Creek in the north-east still has a short section of open stream remaining in the north-east. Land reclamation in the 1960s for the Westfield Rail Yards also reduced the inlet in the east, while the southern shore is less modified. The area is generally known for relatively muddy, sedimented waters, which seem to predate human occupation of the area. Mangrove swamp fringes are present around most of the shoreline, becoming less common west of Mangere Bridge. For many years the many industries, from meatworks and abattoirs, to phosphate fertiliser works and other factories located here were discharging large amounts of untreated waste into the Manukau Harbour. This had a detrimental effect on the ecology of the harbour which at the turn of the 20th century had been a popular and attractive place to swim, sail, fish and gather shellfish. During the 1950s, the decomposition of organic wastes and cars, more so than the CBD location. However, the idea failed to get public traction.
