The Atlantis aquifer is a groundwater resource on the West Coast, north of Cape Town. It has supplied the Atlantis area for decades through managed aquifer recharge. Treated wastewater and stormwater are infiltrated into the sandy aquifer, stored, and later pumped back out through wellfields. The City of Cape Town treats it as one of its alternative water sources, along with the Table Mountain Group aquifer and the Cape Flats aquifer. It also uses these sources to reduce its dependence on rain-fed dams. Eskom has land and infrastructure in the area, including the Koeberg nuclear power station and related facilities up the coast. A formal agreement on water abstraction and effluent disposal would therefore settle access rights, the use of land and roads, and each party's responsibilities for the wellfields.
Groundwater use in South Africa is regulated under the National Water Act of 1998. It requires licensing or authorisation for significant abstraction. The City's water strategy emerged after the 2017–2018 "Day Zero" drought. It aims to diversify supply with groundwater, reuse and desalination so the city can meet demand as its population grows.
The data centre issue raised in the debate is a separate and wider concern. Large "hyperscale" data centres use a lot of electricity and often a lot of water for cooling. The City's tariff increases and its approach to approving such facilities are therefore a matter of public debate. Council decisions on securing water infrastructure are important because they determine how reliably and at what cost the city can supply water over the long term.
I couldn't run a search for this answer, so it comes from general knowledge and has no citations. The City of Cape Town website (capetown.gov.za) has more on the Atlantis aquifer and the water strategy.
