Cape Town's "Day Zero" looms on April 21, when the drought-stricken city will have to cut off water supplies -- unless residents reduce consumption and additional sources come online before that date.
This is causing concern in other big South African cities, where residents worry that they too could soon be trapped in a city running dry.
Speaking to Huffpost, Joburg Water spokesperson Isaac Dhludhlu said that although there are currently level-one restrictions in place in the city, it is still "safe for now".
However, Dludlu stressed that "safe" does not mean that residents should consume water irresponsibly.
"The last time I checked with the department of water and sanitation about a week ago, they indicated that the Vaal dam is just below 80 percent," Dludlu said. "Which means that it is full, and therefore the city is safe.
"However, the restrictions that were in place in 2017 are still in place, with level-one restrictions ongoing... People are still not allowed to water their gardens between 6am and 6pm. They are also not allowed to use hosepipes to wash their cars, but must rather use buckets."
In a statement issued on Monday, Johannesburg member of the mayoral committee Nico de Jager urged residents to reduce their water consumption, as water usage has increased at an alarming rate.
"This is of serious concern, given the recent heatwave we have been experiencing since the beginning of 2018 in Gauteng," the statement said.
Meanwhile, according to water scientist Anthony Turton, it is a "well-known fact" that Gauteng will continue to be a water-insecure region, because of delays in phase 2 of the Lesotho Highlands Water Project, which was supposed to start providing more water to Gauteng this year.
"At a purely technical level, Gauteng will continue to be water-insecure until 2025, and it may only be a matter of time until Johannesburg residents face water restrictions again," Turton said.
Turton explained that this doesn't mean there will be no water in the province, but rather that the assurance of water supply was not at the level that it used to be.
Turton added that South Africa's water problem is not caused by drought, but rather the lack of investment in infrastructure.
"People should not blame drought, but should shift the blame to the country's inability to plan and invest in infrastructure," he said.