- Johannesburg Water's pump stations need electricity to feed the metro's water towers.
- If there is not enough electricity supply some residents may have no water at all at times.
- The country has been on Stage 6 load shedding since Sunday.
Bulk water supplier Johannesburg Water has cautioned continued Stage 6 load shedding will likely impact water supply in the city.
On Monday, the entity said the pump stations, which supply water to the city's water towers, were affected during electrical outages.
It added this had resulted in poor pressure or no water at all in various water zones.
A move to Stage 6 load shedding was announced on Sunday after a week of large-scale breakdowns at Eskom's coal power stations.
Eskom chief executive officer André de Ruyter said high load shedding levels were expected this week.
ROLLING COVERAGE | Eskom and load shedding news as it happens
Increased load shedding, above the planned levels to accommodate maintenance, is expected during summer.
In response to the level 6 announcement on Sunday, Johannesburg Water said it was "monitoring affected infrastructure and ensuring that water supply [was] restored as soon as possible".
But the city was already experiencing water supply issues on level 5 on Saturday.
Residents in the areas supplied by the Brixton, Hursthill and Crosby reservoirs and the Brixton Tower are in danger of running out of water as water levels are low.
"Customers in higher lying areas may experience low pressure or no water due to lower capacity," Johannesburg Water said.
There are planned outages in Lenasia Ext 1. On top of the electricity issues, the city already has level one water restrictions in place.
The restrictions were implemented at the beginning of the month and are expected to run until the end of March 2023.
According to the restrictions, residents were prohibited from irrigating gardens and using hose pipes to clean driveways with municipal water between 06:00 and 18:00.