Rain set to ease but Sydney homes remain under threat as dam close to overflowing 

After weeks of relentless downpours, Sydney residents may finally see the sun again as one of the wettest Augusts in decades comes to a close. Warmer, drier conditions are on the way, but authorities are warning that flood risks remain high, with Warragamba Dam tipped to spill billions of litres of water. 

By Friday evening, Sydney could receive up to 8mm of rain before showers ease into the weekend. From Saturday onwards, totals are expected to fall sharply, with only 0–2mm forecast across the city. By early next week, the gloomy conditions that have blanketed the east coast will give way to clear skies. 

Temperatures are also set to climb, offering a welcome change for residents weary of cold, damp days. Sydney is forecast to reach 20C on Monday, 22C on Tuesday, and a peak of 23C by Wednesday — the warmest stretch in months. 

Weather improvements are expected in other major cities too, as a westerly airstream brings drier air across much of the nation. For the northeast coast, the rain is likely to move offshore by Tuesday, ending weeks of soggy conditions. 

Warragamba Dam expected to spill billions of litres 

Even as skies begin to clear, Sydney’s main water storage, Warragamba Dam, remains under pressure. Authorities have confirmed the dam is almost full and will likely spill on Friday, releasing around 15 billion litres into downstream rivers. 

At 9:30am on Friday, Warragamba was sitting at 98 per cent of its 2000-gigalitre capacity following days of heavy rain. The spill is unavoidable, as inflows continue to surge after more than 90mm of rainfall soaked the dam’s catchment in recent days. 

Smaller dams in the Greater Sydney area — including Woronora, Cataract, Cordeaux, Nepean, Avon, Wingecaribee, and Tallowa — are also spilling, adding further stress to the network of waterways. 

This is not the first time Warragamba has overflown this year. In May, the dam spilled 20 gigalitres after a similar bout of heavy rainfall. Given that Warragamba supplies around 80 per cent of Sydney’s drinking water, its management remains a critical balancing act between water security and flood mitigation. 

Dozens of flood alerts across NSW 

The NSW State Emergency Service (SES) has issued 42 flood alerts as of Friday morning, with warnings stretching from the South Coast city of Wollongong to Goondiwindi near the Queensland border. 

In Gunnedah, on the state’s northwest plains, residents in low-lying areas such as Talibah Flats, Old Blue Vale Road, and Kelvin Road have been urged to prepare for isolation. The SES has warned that major flooding could occur by Friday evening, making some communities inaccessible. 

The SES has already been stretched thin, responding to over 600 calls for assistance since the weather system began. At least 10 flood rescues have been carried out, with all involving motorists attempting to drive through floodwaters — a persistent danger during weather events. 

In Sydney, around 60 homes in Kurnell were impacted by floodwaters on Thursday, with emergency crews helping residents protect property. The Port Macquarie region has also seen a high number of incidents, as heavy rainfall drenches coastal catchments. 

Deputy Commissioner Debbie Platz of the SES noted the challenges of managing two overlapping weather events: “We’re dealing with the earlier flooding from the Namoi and Barwon rivers, and now the coastal and northwest plains are topping up again after the latest rain.” 

Dangerous river levels rising 

In NSW, rivers are rising fast because the ground is already soaked from earlier rain and just can’t take in any more water. 

In just 48 hours, some regions recorded more than 200mm of rainfall. Some of the worst impacts have been in the Central Coast, North West Slopes, Illawarra, and Hunter regions. 

At Gunnedah, the Namoi River is expected to exceed the major flood threshold of 7.9 metres. The Peel River at Tamworth is also forecast to flood, with communities warned to monitor conditions closely. 

Closer to Sydney, the Hawkesbury and Nepean rivers are already experiencing minor flooding, and Menangle Bridge, southwest of the city, has been submerged. Floodwaters have cut off key roads, including stretches of the Princes Highway near Dunmore and Menangle Road in Sydney. 

For Sydney itself, August has already delivered over 350mm of rain — the wettest August in 27 years. This is nearly four times the long-term monthly average. 

The heaviest single-day falls in the past 24 hours included 165mm at Tallebudgera Creek on the Queensland-NSW border, 135mm at Kingscliff in the Northern Rivers, and 80mm at Port Macquarie. These extreme totals have worsened flooding and triggered multiple road closures. 

Forecast: End finally in sight 

For rain-weary residents, there is finally light at the end of the tunnel. The Bureau of Meteorology has confirmed that the weather system responsible for weeks of downpour is moving offshore. 

“We’re seeing this prolonged rainband finally shift away from the east coast,” senior meteorologist Angus Hines explained. “Moisture is being pulled out into the Tasman Sea, which will bring relief to Sydney and the Illawarra.” 

On Friday, rainfall totals are expected to remain under 10mm for Sydney and Newcastle. From Saturday onward, only light showers are predicted, with clear skies dominating the forecast from Monday to Wednesday. 

Warmer weather is coming, which will help dry up some of the waterlogged areas. But authorities say the flood risk isn’t over yet — rivers are still rising, and overflowing dams are sending more water downstream. For many low-lying communities, the danger of flooding will stick around even after the rain stops. 

 FAQs 

1. Why is Warragamba Dam overflowing again? 
Recent heavy rainfall in its catchment has pushed Warragamba close to capacity, forcing the release of excess water downstream. 

2. How much rain has Sydney had this August? 
Sydney has recorded more than 350mm of rain so far, making it the wettest August since 1998 and nearly four times the monthly average. 

3. Which areas are under flood alert in NSW? 
Over 40 alerts have been issued, covering regions from Wollongong to the Queensland border, with major concerns in Gunnedah, Port Macquarie, and the Illawarra. 

4. What rivers are currently at risk of flooding? 
The Namoi, Peel, Hawkesbury, and Nepean rivers are all rising, with some already reaching minor to major flood levels. 

5. When will Sydney’s weather finally improve? 
Rain is set to ease from Friday afternoon, with clearer skies and warmer temperatures expected from Monday through Wednesday.