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.

[3] The idea did not progress, and eventually the Manukau Wastewater Treatment Plant was opened, which included oxidation ponds located between Puketutu Island and Māngere.

[1] 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.

[1] However, industrial sewage mixed with stormwater overflows, and other contamination still leads to above-average traces of toxins like pesticides, insecticides, PCBs and copper in the mussels and oysters sampled by testing.

[4] In the discussions around Stadium New Zealand, constructing the new venue over the eastern shoreline of the inlet was mooted by several architects as a potential alternative to the Auckland CBD location.

They considered that the site would be far enough away from residential areas to suit the need for a large and busy multi-use stadium, but would also be able to be accessed easily by public transport (trains) and cars, more so than the CBD location.