The National Water Forum voiced concern over the pollutive effect of the recent flooding on the country's water supply.

NWF national chairman Louis Meintjies said that in Gauteng, acid mine water levels rose quickly because of the rain and that the acid water had now affected a wider area, with the water pollution spreading.

"The downpours may have diluted the concentration of heavy metals in polluted water but it certainly did not allow contaminants to dissolve," he said.

Meintjies warned that several sewage plants were flooded due to the heavy rains and that raw sewage had ended up in the water systems.

"Farmers have to take note of the possibility of the outbreak of fungi and diseases spread by the contaminated water on farm lands," he said.

Water Affairs ministry spokesman Mandla Mathebula acknowledged that the floods had the potential of contaminating the water.

"We did anticipate cases of flooding and as a result of that we have a team that is looking at that situation," he said,

"We don't think we will have that problem of contamination, we are guarding against that."

Experts from the department were put on high alert to ensure that the country's water supply remained safe, Mathebula said.