17/03/2017 7:01 AM AEDT | Updated 17/03/2017 12:19 PM AEDT

The Body Of Missing 11-Year-Old Bodyboarder Found In Creek Bed

The 11-year-old had been playing in stormwater with his brother and some friends.

An 11-year-old boy has been found dead after he was likely swept into a stormwater drain amid heavy flooding in Unanderra, south-west of Wollongong in NSW.

The body of Ryan Teasdale was recovered on Friday morning from a creek bed at the end of a stormwater drain just 500 metres from where he was last seen while playing in heavy rain.

Teasdale went missing from Riley Park on Thursday wearing only board shorts, with his blue bodyboard.

Superintendent Zoran Dzevlan told reporters on Friday morning that police held strong fears the boy may have been swept into a stormwater drain after riding down a hill on his board.

"We have been searching that immediate vicinity and we have also been searching areas where the drains finish into the creeks and surrounding areas," Dzevlan said.

NSW Police / Facebook
Ryan Teasdale's body was discovered in a creek bed on Friday.

The boy's family raised the alarm on Thursday night after an initial search failed to locate him.

Police Rescue and SES volunteers searched throughout the night and resumed at first light on Friday.

The state's heavy rain has been relentless, with police rescuing 11 people caught in flood waters in the Southern Highlands on Thursday.

Fairfax / Sylvia Liber
Police were alerted after the 11-year-old failed to return home.

Nine vehicles became trapped in floodwaters while travelling west on the Illawarra Highway, Macquarie Pass, when water flowed across the road from an escarpment.

None of those rescued were injured, however emergency services reminded people of the dangers of travelling during extreme weather.

Since Monday, the NSW SES has received over 1,700 requests for assistance.

Fairfax / Sylvia Liber
It is believed that Teasdale was swept into a stormwater drain amid heavy flooding.

Forty-three flood rescues have been carried out in Wollongong and Shellharbour, with a large majority of these being for motorists caught in rapidly rising flood waters.

It was expected that gale force winds would hit the coastal fringe south of Sydney on Friday morning, while heavy rain is expected on the Mid-North Coast and Far North Coast.

There's no sign of the weather improving over the next seven days, with showers expected to continue to hit Sydney.