The City is to shut down the 1 220mm Tygerberg water pipeline from Friday evening to Sunday morning.
The pipe supplies Brooklyn, Sanddrift, Tygerhof, Rugby, Century City, Paarden Eiland, Joe Slovo, Phoenix, Kensington, Acacia Park and Goodwood.
The suburbs will be supplied with water from other parts of the network but residents can expect low water pressure or supply disruptions, the City says.
Water tankers will be stationed near Acacia Park as this area will experience the most disruption, the City says.
The pipeline, between Giel Basson Drive and Jakes Gerwel Drive, will be shut down from 6pm on Friday until 6am on Sunday to allow for a refurbished inline valve to be installed in the Smart Street area.
The faulty valve was removed in May and sent for repairs.
The City wants residents and businesses to use less water from Friday to Sunday to reduce pressure on the network.
Residents are also advised to store water in clean, sealed containers in advance, and to ensure that their taps are left in the closed position during this period to prevent any water loss and/or water damage when the supply is restored.