Heavy rainfall overnight has resulted in Warragamba Dam spilling over, amid evacuation orders and road closures across New South Wales.
Up to 200mm of rain has fallen in parts of the state overnight, while residents in low-lying areas around the Georges River in Sydney’s west are preparing to evacuate.
Residents living along the Nepean River in Sydney’s west were warned the dam had begun spilling at about 4.20am on Friday morning, with the Bureau of Meteorology issuing flood warnings for parts of Sydney, the Illawarra and the South and Central Coast.
The NSW premier, Chris Minns, told reporters the “immediate concern” for emergency crews was for residents in low lying areas south-west of Sydney, “stretching along the coast all the way down to Bega”.
Minns said there were concerns for the Nepean-Hawkesbury region, with the SES deploying “forward operating vehicles and staff” to the region.
“We are expecting potentially flash flooding, an alert in that part of New South Wales. But riverine flooding may be an issue over the weekend.”
The bureau warned that the Upper Nepean River, the Hawkesbury and Lower Nepean Rivers, and the Georges and Woronora Rivers could all face moderate flooding on Friday.
Senior meteorologist at the bureau Angus Hines said rain along the coast was falling on areas already drenched by earlier downpours.
“Even though the rain is forecast to ease later on today, any further wet weather in the next few hours and for the rest of the day will be falling on to saturated land, particularly around the Illawarra, adding to or extending potential flooding impacts.
“There have already been flash flooding impacts with closed roads and inundated homes, and this could continue or even expand with the further rainfall, particularly through the morning hours,” he said.
The Menangle Bridge has been closed amid rushing flood waters, with the NSW SES warning residents the river had risen to over 7.2 metres and could hit 10 metres by midday.
The Sooley Dam in Goulburn has also begun spilling, with the SES warning it was causing flooding of low-lying areas along the Wollondilly River.
The overnight downpour led to evacuations in Picton, south-west of Sydney, where SES volunteers were door-knocking residents to warn them of rising flood waters.
The SES responded to 447 storm-related incidents in the past 24 hours, 291 of them in the Illawarra and South Coast area, 86 in the Sydney Metro area and 12 in the Hunter and Central Coast area.
The bureau has issued a severe weather warning for people in parts of Illawarra and South Coast Forecast Districts, who can expect more heavy rainfall during the day.
They say that scattered six-hourly rainfall totals between 40mm and 60mm are likely with isolated totals of about 100 mm possible.
They also warned that 24-hourly rainfall totals between 75mm and 100mm are also likely with isolated totals of about 130 mm possible.
The heavy rainfall is likely to contract to mostly the Illawarra coastal areas and northern parts of the South Coast during the day.
It comes as a surface trough extending near the coast with moist onshore flow has been generating areas of heavy rainfall.
The trough is expected to slip southwards and weaken with rain areas contracting to Illawarra and South Coast later today, before easing tonight.
Sydney saw 57mm of rainfall in the 19 hours to 5am Friday, amid loud thunder and bright lightning strikes overnight.
