Torrential rains trigger widespread flash flooding across New South Wales

Torrential rain battered large parts of New South Wales on January 17–18, producing life-threatening flash flooding, widespread property damage and multiple rescues as emergency crews worked through the weekend and into Sunday. Flooding shifted north toward the Hunter and Mid North Coast by Sunday afternoon, while authorities warned the risk would persist for at least another 48 hours.

Emergency services reported large-scale operational demands. The State Emergency Service said roughly 750 volunteers were deployed and more than 880 people requested assistance, while ABC reporting placed the total incidents over the weekend at more than 2,300 and cited 25 flood rescues. The original emergency tallies recorded at least 20 people rescued from floodwaters. The SES media release noted specific vehicle rescues in Albion Park, Picton and Marulan, and operations in Liverpool dealing with leaking roofs, collapsed ceilings and other property damage.

Evacuations were carried out in low-lying parts of Sydney’s Northern Beaches, including Narrabeen, where residents were moved because of life-threatening flash-flood risk and, ABC reported, were able to be accommodated nearby. In one dramatic incident on the Northern Beaches a landslide nearly took a house at Great Mackerel Beach. Moruya crews responded to roughly 30 incidents, including leaking roofs, fallen trees and flash flooding, and at least one house suffered a collapsed roof attributed to the heavy rain.

The storm claimed at least one life when a woman in the Illawarra region was struck by a falling tree branch. Roads were closed across multiple locations, prompting repeated warnings from authorities for motorists not to drive into floodwater. State Duty Commander Acting Assistant Commissioner Sonya Oyston urged drivers to take extreme care and to be patient as road closures and damage clearance take time.

Measured rainfall totals underscored the severity of the event. Sydney’s Observatory Hill recorded 127 millimetres, its wettest January day in 38 years. Katoomba endured a record 220 millimetres in 24 hours, and Terrey Hills logged 180 millimetres, its wettest day on record for any month. Moruya received almost 200 millimetres in the 48 hours to 9 a.m. Saturday, and Western Sydney and the Blue Mountains saw intense short-duration falls of up to 68 millimetres in some locations. The SES warned isolated falls of up to 120 millimetres could still occur across parts of the Central Coast and Mid North Coast.

The Bureau of Meteorology and the SES issued multiple flood and severe weather warnings covering metropolitan Sydney, western Sydney, the Blue Mountains and the Northern Beaches. BOM senior meteorologist Dean Narramore said warnings targeted areas "where we are seeing … isolated falls up to 60 to 80 millimetres within an hour and that will cause flash flooding that will continue this morning, slowly easing to moderate rainfall this afternoon." The SES also issued a Watch and Act for the Manly lagoon and advised people not to enter floodwater.

Beyond immediate rescue and relief, the event highlights economic and policy challenges. Repeated extreme downpours strain emergency budgets, increase insurance claims and disrupt transport and local business activity, particularly in coastal tourism and freight corridors. The concentrated, high-intensity rainfall that produced rapid flash flooding is consistent with long-term trends toward more intense precipitation events, increasing pressure on urban drainage systems and land-use planning. Authorities have warned catchments are now wetter than usual, and analysts say sustained investment in stormwater infrastructure, targeted land-use restrictions and improved early-warning systems will be essential to reduce future risk.

Officials urged residents to monitor BOM and SES updates as crews continue flood response and assess damage across affected communities.