More than 700 claims have been submitted to insurers, a figure that is expected to sharply rise as power and telecommunication services are restored in coming days.

The "catastrophe" declaration by the Insurance Council of Australia ensures those claims are prioritised by all insurers.

Assessors will move into affected communities once given the green light by emergency services.

"Access to areas north of Geraldton is limited, so it is too early to understand the extent of the damage to property in the affected region," ICA chief executive Andrew Hall said on Wednesday.

"As yet, there is no estimated loss dollar figure as severely impacted areas are currently inaccessible.

"Importantly, this event has impacted a region not normally affected by cyclones, and the destruction of the built environment is severe."

Prime Minister Scott Morrison is expected to visit Kalbarri, which bore the brunt of the storm, later this week.

Up to 70 per cent of properties in the popular coastal tourist town, 580 kilometres north of Perth, are thought to have been damaged by the cyclone which hit late on Sunday as a category three storm with winds up to 170km/h.

The federal government has made available disaster recovery payments of $1000 per affected adult and $400 per child.

"I am looking forward to going, in a couple of days time, to be able to see first hand on the ground and see what additional support we can provide," Mr Morrison told reporters in Perth.

"I know how self-sufficient West Australians are ... (but) the support is there for you at a time like this."

Power is yet to be restored to about 28,600 homes and businesses.

Western Power said there were outages across the Mid West and Central Wheatbelt in an area spanning more than 700km long and 150km wide.

About 130 poles have been damaged on the transmission side of the network alone.

"We're working steadily to restore power but anticipate that some affected areas will be without power for weeks," the utility said.

"We're working alongside emergency services and other state government agencies to ensure the community has safe access to power as soon as possible."

A combined state and federal disaster relief package for communities battered by Seroja is yet to be finalised but is expected to exceed the $18 million spent on the Wooroloo bushfires which destroyed 86 homes near Perth in February.

Seroja is the third disaster to be declared an insurance catastrophe this year.

Losses from the Woorooloo bushfires stand at more than $85 million from 995 claims, the ICA said.

Major floods in NSW and southeast Queensland last month have resulted in losses of about $600 million from more than 40,000 claims.

Australian Associated Press