Cape Town – The City of Cape Town drilled its first test borehole into the Cape Flats aquifer on Thursday, hoping that the earth's natural underground reservoirs would provide an extra 80 million litres of water per day as dams dry up in a prolonged drought."This is the first in the history of the City of Cape Town that we're going to drill for water and extract that water that's been there for millions of years," said Mayor Patricia De Lille during a site visit in Mitchells Plain on Thursday.The City has a licence to extract 80 million litres of water from the Cape Flats Aquifer per day, 40 million from the Table Mountain Group Aquifer and 40 million from the Atlantis Aquifer.WATCH: Latest drone footage of Theewaterskloof Dam, now 16.8% fullThe drilling, however, is just the first stage of possibly rescuing the city from "Day Zero" – when it has no more water to pump to its residents, businesses and visitors – it does not mean that the water is available immediately.Water samples must be tested, and specialists will determine the extent of the treatment and purification it needs ahead of the installation of reticulation pipes that connect the water to the overhaul system.The team plans to drill at several pre-identified sites to find the highest yielding points as quickly as possible.Cost-effectiveThe first drill site was based at the waste water treatment plant in Mitchells Plain. The team laid out piles of different coloured wet soil which had been extracted, to demonstrate the depths drilled so far.In blazing heat, blue PVC pipes were joined to be sunk into the hole to start bringing water to the surface."I am excited," said machine operator Elias Leshaba, taking cover from the treeless dune heat under a truck while the mayoral visit was underway."We drilled the whole night," said hydrogeologist Derek Whitfield of the small team tasked with saving the city from the drought. De Lille believes aquifer extraction will bring bigger volumes of water into the city's systems at a much reduced cost compared to other methods, such as desalination.She said that the aquifer water would be replenished by treated waste water as it is removed.Day Zero loomsThe City will drill in Strandfontein, Philippi, Wesbank, Bishop Lavis and Khayelitsha to look for the best abstraction points.The City has warned that if it does not get below its current average usage of more than 500 million litres per day, it will run out of water sooner than expected.Wednesday's use was 593 million litres.If that trend continues, Day Zero will be brought forward. Its current estimated date is April 22, 2018.Should the city's taps run dry, residents will be limited to 25 litres of water per day, collected in a queue with a container and monitored by police and possibly the military. The current limit is 87 litres per day.In the meantime, the City is also expanding its water pressure reduction programme with pressure management technology.Controversial drought chargeThe first planned works will be in Paarden Eiland, in the area bounded by the Marine Drive Service Road to the north, Duncan and Lower Church roads to the west, Paarden Eiland Road to the east and FW De Klerk Boulevard (N1 freeway) to the south.About 367 customers will be affected.The work is scheduled to start on Thursday, January 11, from 20:00 to 04:00.Pressure management means reducing the pressure so that less water is released every time a tap is opened.The City is hoping to raise the money for all these projects through a controversial drought charge. Comments for this close on Monday, January 15, at midnight.The average dam level was at 29%, the City announced on Tuesday.