Some areas in the Gold Coast and northern NSW border region have recorded more than 350mm of rain since Saturday, with warnings there is more to come.

Streets are awash in communities in both states and king tides and big swells have inundated beaches.

Four people were rescued from floodwaters in NSW overnight and about 20 caravaners were moved to higher ground.

Emergency services received more than 1200 calls for assistance for roof damage and leaks, inundation and fallen trees.

"The rains are here and they are coming significantly and in a heavy severe way ... similar to a category one cyclone event," Queensland Fire and Emergency Services Minister Mark Ryan told reporters on Sunday.

"This will be a significant event over the next 24 hours. We've got crews on stand-by ready to respond."

Authorities warn more heavy rain, damaging winds and king tides are likely from Fraser Island to Port Macquarie throughout the evening.

"We've seen significant rain over the last 24 hours much of which has soaked in. The message now is that the soils are damp and any rainfall we get is likely to run and we're likely to see that risk of flash flooding and flooding in low-lying areas," Queensland Fire and Emergency Services commissioner Greg Leach said.

Motorists have been told to stay off the roads and not to attempt to drive into any floodwaters.

The Bureau of Meteorology has also issued a flood warning for southeast Queensland, with inundation possible in coastal and low-lying areas including the Brisbane River.

In NSW, flooding is likely in the Northern Rivers and Mid North Coast areas.

Further heavy rainfall up 300mm is possible.

"This is a dynamic weather system and you should always expect the unexpected," BOM hydrologist Justin Robertson said.

Communities in flood-prone areas spent the day sandbagging low-lying areas and preparing properties.

The warnings are likely to last into Monday.

"We are really appealing to residents in the mid-north coast and Northern Rivers to stay vigilant, monitor your local conditions and local forecasts and stay out of floodwaters," NSW State Emergency Service Assistant Commissioner Dean Storey said.

Rough seas and wild surf are also forecast, with waves of more than five metres tipped from early Monday.

All Gold Coast beaches have been closed along with the majority of Sunshine Coast beaches.

Upper Springbrook in the Gold Coast hinterland recorded 475mm of rain overnight and Couchy Creek, near the Queensland and NSW border, received 365mm of rain since 9am on Saturday, with Numinbah recording 348mm and Chillingham 306mm.

Flood warnings have been issued for the Tweed, Wilson, Bellinger and Brunswick Rivers and Marshalls Creek in NSW and the Logan and Albert Rivers in Queensland.

Meanwhile, flood warnings are also in place for Western Australia's De Grey River catchment after a gusty tropical low dumped heavy rain from the Pilbara to the border with South Australia.

The weather system crossed the coast near Port Hedland on Friday and it started bucketing down as the weather system moved southeast towards the Goldfields.

Warnings have also been issued for the town of Warburton, near the SA border, the Sandy Desert and the Salt Lakes District rivers.

Australian Associated Press