Flooding threats are persisting for regional communities in the wake of a powerful cyclone that tore through Western Australia's north.

Tropical Cyclone Zelia brought heavy rain and damaging winds after crossing the coast near Port Hedland as a category four on Friday, before weakening to a tropical low as it tracks south.

No deaths or injuries were reported as alert communities escaped the worst of the severe weather, the state government and emergency agencies confirmed.

River levels have begun to ease in the Pilbara region but the flood threat has not completely passed. 

Cyclone Zelia made landfall at Port Hedland as a category four, bringing heavy rain and damaging winds. - AAP

A major flood peak was observed along the De Grey River at Coolenar Pool, east of Port Hedland, early on Sunday morning. The river level was at 8.98 metres and above the flood levels of March 2000.

The river level was falling slowly, but renewed rises were possible as floodwaters arrive from upstream.

Major flooding was also recorded along the Nullagine River at Nullagine and Tumbinna Pool, and along the Coongan River at Marble Bar and Marble Bar Rd Crossing.

A flood watch remains for the Fortescue, Ashburton and Gascoyne Rivers, while a major flood warning for the De Grey River catchment was in place on Sunday morning, the Bureau of Meteorology said. 

The bureau had issued a flood watch and act for the De Grey catchment, including Marble Bar and Nullagine, warning residents to prepare for isolation. A flood warning was also in place for the Pilbara Coastal Rivers.

A satellite image of Tropical Cyclone Zelia over the coast of Western Australia. – AAP

Emergency crews in WA are assessing the damage, but the downgraded weather system was still dumping significant rain on parts of the Pilbara region, exacerbating flooding.

Major roads have flooded, cutting off critical connections for supply deliveries including the Northwest Coastal Highway between Port Hedland and Broome.

"We're working closely with the major supermarkets to ensure the Pilbara and Kimberley remain well-supplied while the road closures are in place," WA Premier Roger Cook said.

WA Fire and Emergency Services Commissioner Darren Klemm warned heavy rain and flooding was not expected to subside until next week.

Warnings are also in place in flood-devastated areas of Queensland as residents return home to count the cost of the big clean-up.

Flood alerts include a major warning for the Lower Flinders River, and a moderate warning for the Thomson River remained current.

Queensland Premier David Crisafulli said efforts have now shifted from response to recovery as residents face a lengthy rebuild.

"The heartache, the devastation, the level of damage is something the likes of which I never thought I'd see in that part of the world," he said.