Emergency services spokesperson Roggers Mamaila said continuing rains on Monday presented the possibility of flash floods.
The municipality called on residents and businesses in low-lying areas to guard against rapidly raising water, Mamaila said.
Phomolong in Thembisa, Highlands in KwaThema and Spruitview in Vosloorus were “notorious” for flooding, and the municipality’s emergency personnel were monitoring these areas.
Mamaila asked that the community contact the emergency call centre as soon as the water level rose above ankle level inside the house or shelter – 011-458 0911 (paid number), 10177 (toll free) or 112 from a cell phone.
He urged drivers to exercise extreme caution in the wet weather and to beware of low level bridges.
Heavy rains to continue
Earlier, the SA Weather Service said heavy rains experienced on Sunday night and early Monday morning were set to continue on Tuesday in Gauteng and eastern parts of North West.
By mid-morning on Monday most of the day’s rain had already fallen, with 52mm in Johannesburg, 28mm in Pretoria, 50mm in eastern parts of the North West and 45.4mm in Bela Bela, forecasts said.
The rain was likely to return on Tuesday, with 60% rain predicted in Gauteng.
Parts of the Free State, western KwaZulu-Natal and Lesotho were expected to experience significant rain on Tuesday.
SMS warnings of possible flash floods had been issued in the eastern North West.
Drivers are urged to take precautions in the wet weather, with a number of accidents on Monday attributed to slippery conditions on the roads.
Reports of high waves reaching four to six metres are expected from the West Coast of the Northern Cape all the way to Port Alfred in the Eastern Cape.
The weather service stressed that these conditions are not linked to the tsunami originating from Japan’s recent earthquake.