Zurich-based catastrophe data company Perils has lowered its insured loss estimate for the NSW and Queensland flooding catastrophe in March to $916 million, down from an initial estimate of $1.06 billion last month.

The losses cover property and motor lines of business, and are based on data collected from most of the Australian insurance market.

The March 18-24 disaster affected mainly NSW’s Mid North Coast and the Hunter and Greater Sydney regions, and adjacent parts of southeast Queensland and eastern Victoria were also affected by storm and flood damage.

The extreme period of rainfall resulted in major river and surface water flooding and the peak exceeded historical records.

The event was caused by a blocking high pressure system in the Tasman Sea and a low-pressure system off Australia’s northwest which fed large volumes of moist tropical air into eastern Australia.

Perils will provide an updated estimate in September detailing the industry loss by postcode area and lines of business.