The consequences of flooding and not just the probability needs to be taken into account as climate change and expanding urban populations bring increasing risks, a report released by the Insurance Council of Australia (ICA) says.

The report says land planning for new developments must look beyond standards that generally require that new houses shouldn’t be located within a 1-in-100 annual exceedance probability (AEP) flood zone.

The Flooding and Future Risks report, which draws on analysis by the James Cook University Cyclone Testing Station in association with Risk Frontiers, says data suggests home being built above the level are sustaining an unacceptable level of risk.

Recommendations include that new development planning should take into account the full range of possible flood events, including larger and rarer floods, and that climate change projects over the lifecycle of a building should be considered.

ICA says the impacts of floods above the 1% rate can vary significantly between locations and a one-size fits all approach across Australia doesn’t work.

“It’s critical to consider the full range of flooding events in each location before building new developments, as well as considering what these risks might look like in the future under a changing climate,” a spokeswoman said.

Estimates show more than one million private properties, or about one in ten homes, have some level of flood risk and the total cost of floods has topped $21.3 billion since ICA records began in 1970.

The report also calls for building code changes to promote resilience, and proposes action to address data gaps that prevent insurers and homeowners from gaining an accurate picture of the risks.

“Whilst the majority of flood studies undertaken by local governments since 2015 consider climate change risk, there is a lack of consistency in approaches, older datasets rarely consider climate change and newer datasets are either unavailable or difficult to access,” it says.

The report calls for more fixed and mobile flood gauges and says surveys should be funded by governments on an ongoing basis to ensure key data is observed.

The Federal Government should also establish, maintain and make freely available an Australian Historical Flood Depth and Extent database that represents the depth of water experienced at properties, it says.