Zurich-based catastrophe data company Perils has put its initial insured loss estimate for the NSW and Queensland flooding catastrophe at $1.06 billion.

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

The March 18-24 disaster affected mainly NSW’s Mid North Coast, and the Hunter and Greater Sydney regions, as well as adjacent parts of south-east Queensland.

“During the week ending March 24, the east coast of Australia experienced extreme rainfall over both a wide geographic area and an extended period,” Head of Perils Asia Pacific Darryl Pidcock said.

“The resulting damage from storm drain water and river flooding was considerable, especially for NSW, where the event represents the largest industry flood loss on record.

“While damage to private property was largely insured, there were cases where policyholders decided to opt out of flood cover reminding us of the challenges the industry still faces in offering sustainable and affordable flood risk protection in Australia.”

In a separate update, Perils has revised its insured property and motor loss estimates for last October’s “Halloween” hailstorms in Queensland to $1.17 billion.

The revised number is down from the $1.3 billion Perils provided in its previous loss report for the storm event.

The latest third loss report provides a detailed breakdown of property and motor losses by postcode, with the data further divided by residential and commercial lines, and loss amounts split into buildings, contents and business interruption losses where available.

The Insurance Council of Australia declared the October 31 storm event a catastrophe.