People in the Mollymook Beach area are advised to avoid ocean recreational activity due to a sewerage overflow following the recent heavy rainfall.
The Mollymook Beach area received very high rainfall and the local sewerage system has reached its storage capacity, resulting in unavoidable diluted sewage discharges.
Shoalhaven Water was called into fix a break in a sewerage pipe in the area and the water quality has been assessed.
Signs have been erected and water quality results will be available later in the week.
People should avoid swimming until a further notice.
Council has been working with the NSW Environment Protection Authority (EPA) and NSW Health in relation to the situation.
Tidal currents, wave action and ocean swells will ensure that the pollution will disperse quickly.
However, waterways are expected to be impacted on for several days.
People, as a result of the flooding across the Shoalhaven, are advised to avoid swimming if there are signs of pollution such as discoloured water, oil, scum and litter or other debris floating in the water or on the tide line.
"In times of heavy rainfall water can also be contaminated with sewage or chemicals," council said in a media alert.
" This contamination may continue for some time after the rain subsides and it is recommended that people do not swim in oceans for 24 to 48 hours after heavy rain.
"Avoid rivers, lagoons or estuaries affected by floodwaters and runoff for three days."
The NSW State Emergency Service (SES) advises people not to enter floodwater due to hazardous conditions.
For emergency help in floods and storms call the NSW (SES) on 132 500. In life threatening situations, call Triple Zero (000) immediately.