“These impacts could include large and dangerous surf, strong winds and heavy rain,” he said, cautioning that “dangerous wind and rain would only occur if the system gets close enough to the [Australian] coast, while powerful surf can reach Australia even if the system stays well offshore”.
NSW beaches, including those near Sydney, were battered by abnormally high tides and swells generating six-metre waves. While places such as Collaroy on Sydney’s northern beaches retreated by as much as 25 metres, they were spared worse damage because the wave direction was more to the south than expected, Mitchell Harley, a coastal researcher with the University of NSW, said.
“It made a huge difference,” Dr Harley said, with the worst of the erosion shifted about 500 metres to the north of the most vulnerable areas that had been hit hard by storms in 2016.
However, this week’s tempest meant “we’re left with considerably depleted beaches”, and return of large waves within days would “be a big concern”, he said.
The Bureau of Meteorology is forecasting the worst of Uesi to remain offshore. Sydney is in for showers all week, with a possible storm forecast for Wednesday.
More rain will hinder the clean-up after the city received almost 400 millimetres of rain in four days to Monday morning. It was the most for such a stint since February 1990, and more than Sydney received in the previous six months combined or that Melbourne collected in all of 2019 [374mm], bureau data showed.
The deluge forced the closure of roads, including the Wakehurst Parkway, the Henry Lawson Drive and the Illawarra Highway. Rail commuters were told to allow extra time to get home with a range of lines – including the Blue Mountains, eastern suburbs, and the South Coast – facing disruptions.
The heavy rains brought renewed joy for firefighters, with the giant Gospers Mountain fire – which burnt more than 500,000 hectares – among 30 fires formally declared extinguished.
There was also relief for catchment managers, although their pleasure at seeing massive inflows into their dams will be tempered by concerns of erosion and possible nutrient influxes especially in areas where fires had been burning. This includes Warragamba, which accounts for 80 per cent of Sydney’s storage.
Sydney’s dam levels may increase by as much as 30 percentage points from the recent deluge, erasing more than a year’s decline.
WaterNSW said overall storage had rocketed to be almost two-thirds full as of Monday, after being 42.7 per cent full just days earlier. The gain over the past week was 22.3 percentage points, or an increase of more than half.
Despite the surge, the level-2 restrictions on water use remain, SydneyWater said.
Premier Gladys Berejiklian said it was too soon to think about changing the restrictions.
A spokeswoman for the Sydney Desalination Plant, however, said the Sydney Metropolitan Water Plan provides for a minimum run time of six months at full capacity since its restart – a period that it has exceeded.
“If a decision is made to stop production, the flow immediately ceases and the plant is gradually shutdown within the confines of the process,” the spokeswoman said, adding there is no provision for compensation.
While some 79,000 customers remained without power as of Monday evening, crews were planning to work through the night. Those without electricity included the home of Matt Kean, the state’s Energy and Environment Minister.
Ausgrid crews alone were dealing with 3100 hazards including fallen powerlines, trees, and damaged wired.
Ms Berejiklian praised the work of emergency service workers after a “torrid couple of days”.
The efforts included the evacuation of 1500 residences overnight into Monday but most of those were back home on Monday night.
Peter Hannam writes on environment issues for The Sydney Morning Herald and The Age.
Matt Bungard is a journalist at The Sydney Morning Herald.