Monster waves combined with a king tide have smashed Sydney overnight, affecting some properties and causing damage along the coastline.

The wild seas drew spectators to viewing points to watch five-metre surf pound against rock walls and pummel Bondi Beach.

Properties at Dolls Point, in Botany Bay, reportedly began to take in water about midnight at a level long-time residents had never seen before.

Several properties were evacuated and sand-bagging began late on Tuesday as the two-metre king tide lapped at homes.

Major swells were still battering the coast on Wednesday morning, attracting some daredevils to enjoy the extreme ride.

The weather bureau said a deep low in the Tasman Sea was driving strong winds, gusty showers and damaging-to-hazardous surf along much of the NSW coast.

“Large waves of up to five metres have been recorded off Eden and waves approaching  five metres have been recorded along the Sydney coast,” said BOM.

“This very heavy surf may lead to damage and erosion of beaches and exposed coasts, especially south of Smoky Cape.

“It will also mean conditions along the east coast become more dangerous for activities like swimming, rock fishing and boating due to the rough seas.”

“Large waves are forecast for the NSW and southern Queensland coasts for most of this week.”

Photographer Bow Caddy Media captured pictures of breaking waves in Sydney Harbour for the first time.

“We’ve been shooting Sydney Harbour from the Caddy’s Crow’s Nest for almost 20 years, but we don’t recall ever capturing large breaking seas in the middle of the Sound, until today,” Bow Caddy Media posted on Facebook.

“There were huge seas all day with the swell coming from the east and the strong south-west winds whipping the tops off the waves.

“From Dobroyd Head to the Bombora off Manly, there was surf everywhere! The ferry rides would have been fun too.”

Record flooding

In south-west Queensland, the entire population of Thargomindah has fled for higher ground after a levee broke its banks, as record flooding continues.

Residents headed to the airport on Monday night after floodwaters exceeded the local record of 6.78 metres.

By Tuesday, water levels were 7.5 metres, and rising.

The population of about 220 people had moved to a council depot on Tuesday. Another night at the airport was possible as they endured the worst flooding seen in more than 50 years.

“This beats the 1974 floods,” local Nancy Sparks said.

“It’s pretty devastating for this little town but we are trying to hold it together, as much as we can.”

Floodwaters twice the size of Victoria have hit western and southern inland Queensland, with no relief in sight.

Locals have been warned that water levels could rise again with the remnants of ex-tropical cyclone Dianne bringing more rain.

The heaviest falls are expected in southern Queensland and northern NSW on Wednesday, with totals of more than 100 millimetres in some areas.

Homes go under in Thargomindah. Photo: AAP/Bulloo Shire Council

More rain will ensure further hardship for graziers, sparking fears some will lose all of their stock.

Homes have been destroyed, roads cut off and fences damaged, forcing many evacuations across the region.

The army is helping with supplies to keep livestock fed but more than 100,000 sheep and cattle are already believed to have been lost.

The extent of the damage won’t be known until the flooding eases, which could take weeks.

“The level of devastation is immeasurable,” Queensland Premier David Crisafulli said.

Local helicopter pilots have gathered to help, with Adavale’s population of about 30 people in the south-west rescued in recent days.

They have also combined to help drop off food supplies and livestock fodder, with roads cut or badly damaged by flooding.

“A lot of the creeks are still up and what roads are open, they’re pretty gouged out,” said Anne-Maree Lloyd, who had to evacuate her Jedburgh homestead near the Barcoo River.

“Semi-trailers with a full load of hay just wouldn’t get along them.

“The logistics of getting that supply into where it’s needed is a big issue at the moment. There’s just so much water around.”

Major flood warnings have been issued from the Northern Territory border, through central and southern inland Queensland and down to NSW.

Communities are expected to be isolated for more than two months in NSW after more rain hits.

“The significant rainfall in Queensland is slowly making its way through the catchment and moving through western NSW,” NSW SES Commissioner Mike Wassing said.

“We are talking of isolation potentially for six to 10 weeks for some of those communities.”

Back at Thargomindah, some locals worked more than 24 hours straight to try to save the town, only for the floodwaters to burst through the levee.

But Ferguson said spirits remained high despite the flooding.

“I couldn’t praise the community enough. Everyone has pulled together,” he said.