Director of Gauteng Provincial Disaster Management Centre at Department of Cooperative Governance and Traditional Affairs (Cogta), Dr. Elias Sithole, says people of Alexandra Township near the Juskei River are being moved to safer areas as more heavy rains are expected this evening.
Flash floods left residents homeless after their shacks were swept away.
Sithole says there were floods near the river last year, and people were relocated to the nearest church and creche, but other people went off to build other shacks.
He says drainage systems are blocked by materials used by homeless people who sleep on the roads and under bridges.
Six people have lost their lives in parts of Johannesburg, Ekurhuleni and Tshwane.
Listen to the audio below to hear what to do when it floods...
See our gallery below for pictures from yesterday's floods...
These two truck drivers are being hailed as heroes after saving many lives.