The Florida Commission on Hurricane Loss Projection Methodology has certified the KCC US Flood Reference Model Version 2.0 - the first flood model found acceptable by the commission under the latest standards.

It is the only flood model to be approved under both the prior standards and the current standards, the Karen Clark & Company said today.

“Recent hurricanes, including Helene, demonstrate how important flood damage is from both storm surge and inland floods,” said Karen Clark, KCC president and chief executive.

“Even if insurers don’t write flood policies specifically, it’s important to know which policyholders are likely to experience flooding in the future. KCC’s advanced model provides insights into the locations most at risk from storm surge and inland flooding.”

University of Bristol flood models estimated that up to 60 million Americans are at risk from flooding rivers.

The UK institution said that average flood losses had increased steadily to nearly $10 billion annually. The National Flood Insurance Programme is $25 billion in debt, not counting the projected $16 billion cost of hurricanes Harvey and Irma last year.

Glen Daraskevich, KCC senior vice-president said: “KCC experts in meteorology, hydrology, engineering, statistics, actuarial science, and computer science ensure the KCC models stay up to date with the advancing science and most current atmospheric data."

KCC said their flood model provided a high-resolution view of both coastal flooding from storm surge and inland flooding from extreme rainfall.

The model includes a catalogue of more than 100,000 flood-intensity footprints created and stored at 30-metre resolution along with thousands of vulnerability functions accounting for important property features, such as building construction, height, first-floor elevation, type of basement, wet and dry flood proofing, and other secondary characteristics.

Daniel Ward, KCC senior director of Model Development, said Version 2.0 included many enhancements, including the incorporation of the effects of climate change to date, which he said had led to an increase in the frequency and severity of coastal and inland flooding.

Dr Ward said: “The updated model also explicitly represents urban drainage systems, which is especially important for coastal cities like Miami and Tampa.”

The KCC model accounts for variations in soil properties and flow and depth for riverine flooding have been extensively validated with all available USGS stream data. The storm surge peril is coupled with KCC’s high-resolution hurricane model.