If the weather forecast the next four days eventuates, the Illawarra and South Coast will have the best rainfall in months.
But, with water catchment areas ravaged by the recent fires, attention has now turned to making sure drinking water is not contaminated by ash runoff and other debris.
The giant Green Wattle Creek fire burnt around most of Lake Burragorang, which supplies water for Warragamba Dam.
As it spread through the Blue Mountains and Southern Highlands the same fire created huge plumes of smoke and ash in the regions surrounding the Nepean, Avon and Cordeaux dams.
Meanwhile Tallowa Dam, which joins up with the Shoalhaven River, was overrun by the Currowan fire on Janaury 4.
Bushfire ash contains material such as phosphorous and nitrogen, which, if sufficient rain falls in a short time, could be pushed into dams.
The Bureau of Meteorology has predicted an 80 per cent chance of showers for Thursday, and a 90 per cent chance on Friday with falls of up to 15mm.
The office of Minister for Water Melinda Pavey said these "low intensity" falls predicted did not pose a risk to water quality, as it was not sufficient to wash material into dam storages.
She also said the government had "silt curtains" and floating barriers at the ready to protect various dams across the state.
"The recent fires threatened significant water infrastructure at Warragamba," she said.
"WaterNSW are on-site ... deploying silt blankets and floating booms to ensure key water inflow points to the dam storage are safe to access."
"[These] help to mitigate the inflow of ash into dams, reducing additional pressure on water treatment plants.
"WaterNSW has an additional 1,000m of silt curtains in case they are needed in either Nepean or Tallowa Dams."
Water quality in key metropolitan supply storages, are being monitored by highly experienced scientists using real-time technology, she said.
The greater Sydney dams, which service the Illawarra, have dropped to 42.6 across the network of 11 dams.
Meanwhile, without more significant rain, the government will be forced to fast track the next level of water restrictions.
Level 3 restrictions were slated to be implemented once dam levels hit 30 per cent, originally predicted to happen in July.
At present, Warragamba - which is by far the largest - is at 43.6 per cent, while the second largest Avon Dam is at 44.1 per cent.
The third largest and closest to the Illawarra, Cataract Dam was taken off-line in September due to low water levels, and has now dropped to 25.5 per cent.
The overall dam levels are dropping by about 0.5 per cent each week, according to Water NSW.