The Gift of the Givers is expected to unveil its Beaufort West Witperd aquifer development project in the drought-stricken town on Monday afternoon.
Last month, the Western Cape government denied that the town of about 37 000 residents had reached "Day Zero" with water supply.
A spokesperson for the local government said Beaufort West had "simply run out of surface water".
The Gift of the Givers, a humanitarian organisation, will formally open the project on Monday afternoon, which will see the project pump two million litres of water from new aquifers into the Gamka Dam pipeline and into the town's water reservoir.
The organisation's Dr Imtiaz Sooliman thanked the University of the Free State for testing all its samples as it prepared for the launch on Monday.
He said the project would be providing the town with about two million litres of water daily.
Responding to claims on social media that Beaufort West had run out of dam water in November, James-Brent Styan, spokesperson for Local Government, Environmental Affairs and Development Planning, said the town had 32 operational boreholes.
He said besides Beaufort West and the City of Cape Town, "other worst affected areas were Kannaland, Knysna and Bitou".
Cape Town Mayor Patricia de Lille said the City of Cape Town anticipated that the supply of municipal water would run out by early 2018.
In October, Water and Sanitation Minister Nomvula Mokonyane urged De Lille and Bredell to address water losses due to leaks, to further prevent unnecessary wastage.