Editing Onehunga (section)

== Geography ==
Onehunga lies on the [[Auckland isthmus]], on the northern shore of Mangere Inlet, an arm of the [[Manukau Harbour]], and just south of the [[volcanic cone]] of [[Maungakiekie / One Tree Hill]]. The Port of Onehunga, on Manukau Harbour, is now much smaller than Auckland's east coast port on the [[Waitematā Harbour]], but in the 19th century it was the larger. The wharves are located on reclaimed land bordering a low volcanic crater called [[Te Hopua]], once occupied by a tidal lagoon opening to the southwest, but which has also been reclaimed.<ref>{{cite book |last=Searle |first=Ernest J. |title=City of Volcanoes: A geology of Auckland |year=1964 |isbn=0-582-71784-1}}</ref>

Onehunga's southwestern side, near the Manukau Harbour, lost its direct waterfront access when the [[Southwest Motorway]] was built there in the 1970s. Only a tidal lagoon remains on the city side, though in 2008, there were proposals that the motorway (which was to be widened) could be sunk into a trench to provide direct access to the harbour again.<ref>{{cite news|last=Dearnaley|first=Matthew|title=Preparatory work starts on Onehunga duplication|url=http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10535074|access-date=25 October 2013|work=[[The New Zealand Herald]]|date=1 October 2008|page=A7}}</ref> In 2013, a project was underway to restore the Onehunga foreshore,<ref>{{cite news |last=Thompson|first=Wayne|title=Work begins on Onehunga's $28m harbourside parkland|url=http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10848398|access-date=25 October 2013|work=[[The New Zealand Herald]]|date=19 November 2012}}</ref> to be connected to the city-side park by a pedestrian and cycle bridge over State Highway 20.

A substantial [[aquifer]] flows underground beneath Onehunga, fed by rainwater soaking through the lava flows around Maungakiekie / One Tree Hill. Up to 21 million litres of [[drinking water|potable water]] a day is pumped from the Onehunga aquifer and treated in a local plant before being supplied to Onehunga as part of the Auckland water supply network.<ref>{{cite web |url= https://www.watercare.co.nz/Water-and-wastewater/Where-your-water-comes-from/Groundwater-and-springs |title=Groundwater and springs |publisher=Watercare |access-date=8 March 2020}}</ref> While most of Auckland's potable water comes from reservoirs in the Hunua and Waitākere Ranges, or from the Waikato River, the Onehunga aquifer provides around 5%. In contrast, while the isthmus's other major aquifer, the [[Western Springs Reserve|Western Springs]] aquifer, is also fed by water seeping through lava fields, it is no longer used as a source of potable water.