Flooding rains, storms cause havoc in the Illawarra

In the five hours between 9am and 4pm, Bellambi copped 116 millimetres of rain, Albion Park was drenched with 92 millimetres, while Kiama escaped the worst of it with just under 24 millimetres.

The majority of the rain fell in just a short period of time: Bellambi had 95 millimetres in the hour to 11.59am.

Read more: $10k washed away - Thirroul clothing store struck hard by downpour

As a result of the downpour a landslide occurred at Coalcliff, spilling earth and vegetation across Lawrence Hargrave Drive.

This resulting in a bus getting trapped on the Sea Cliff Bridge for a time, because it was unable to go forward and could not turn around.

In the Royal National Park, a couple of vehicles were swept off Audley Weir into the Hacking River in the early afternoon, but the occupants made it out safely.

Another unfortunate person's car went for a swim in the ocean, the force of the water flowing through the creek at Stanwell Park pushing it out to the sea.

Numerous roads were closed at points during the day as a result of the flash flooding, but it was not just the usual thoroughfares, like Terry Street in Albion Park, that were affected.

The Princes Highway was closed in both directions at Albion Park Rail, Lawrence Hargrave Drive shut between Coalcliff and Clifton, Northcliffe Drive at Kembla Grange went under waist-deep water, and the M1 Princes Motorway was affected in areas such as Dapto and Berkeley.

This caused significant traffic delays, particularly through areas like Unanderra, Thirroul and Dapto.

Videos and photos shared online by residents of the Illawarra showed how some streets had turned into quick-flowing torrents.

Residents of Farmborough Heights and Unanderra described their local streets as "raging like a river".

Read more: Waves of water in Wollongong streets: your photos

"I've lived here 15 years and it's never been this bad at this house before," Unanderra resident Jen Lee said.

Trains stopped running between Kiama and Waterfall due to flooding on the tracks, but the weather's impact on the roads meant replacement buses were also unavailable.

Houses and businesses were also flooded as the water rapidly rose, while sportsfields across the region and Wollongong Botanic Gardens were shut.

Among those affected was the Illawarra Light Railway Museum, which was expected to remain closed until at least Saturday.

Meanwhile, schools including Woonona High School, Kanahooka High School, Koonawarra High School, Para Meadows School in North Wollongong, Good Samaritans Catholic Parish Primary School in Fairy Meadow and St Joseph's Catholic Parish Primary School in Bulli sent students home early as a result of the inclement weather.

Emergency responders were kept busy as a result of the inclement weather: at one point, the State Emergency Service was receiving a call for help every minute as rain continued to pelt down.

The SES recorded over recorded over 350 incidents in the Illawarra - mostly storm damage - as well as 21 rescues from floodwater.

These included rescues from both vehicles trapped in floodwaters, as well as retrievals from buildings.

All involved were safe and well.

SES Wollongong deputy unit commander Edward Forbes said most calls for help were concentrated in the Unanderra, Thirroul and Bulli areas, although the requests came in from across the region.

The Bureau of Meteorology issued a number of warnings throughout the day, advising "very dangerous" thunderstorms were affecting different parts of the region.

But Mr Forbes said the storms arrived suddenly and caught many people off-guard.

Read more: Shellharbour lifeguard's efforts to save boy struck by lightning honoured

"It was quite unexpected, in that the volume of rain was not expected," Mr Forbes said.

SES units from Wollongong, Dapto, Shellharbour and Kiama were expected to remain out in the field responded to requests for assistance into the evening.

Mr Forbes said another influx of calls was possible in the late afternoon, once people returned home from work and discovered damage to their homes.

He reiterated that people should never drive, walk, ride or play in floodwaters.

The situation could escalate and become tragic very quickly, Mr Forbes said.

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