The US National Flood Insurance Program (NFIP) has been urged to withhold federal insurance for new properties built in flood zones.

A Zurich report on last year’s Houston floods, caused by Hurricane Harvey, also calls for tougher coverage requirements for properties on floodplains.

Hurricane Harvey was the second-most costly hurricane the US has seen, dumping more than a metre of rain in eastern Texas.

Making flood cover available for flood-zone properties increases the high-risk insurance pool and puts the NFIP’s viability in question, according to the report – based on a study by resilience centre ISET International and the Global Disaster Preparedness Centre.

Repeat-loss properties should be bought out or undergo flood mitigation work to prevent regular NFIP payouts, the report says.

To rebuild properties “as was” traps owners in a cycle of loss, it finds.

Government and private insurers should explore bundling flood insurance into multi-hazard policies to increase affordability. The industry should start using worst-case regional scenarios from historical records to plan for future disasters, rather than relying on statistical analysis and current conditions to design infrastructure.

Land-use regulations must be reformed and better drainage systems built, with better co-ordinated land development and flood prevention efforts. 

The report also says the US insurance industry should be more careful in the language used to describe extreme floods, so people better understand the risk. It should avoid using phrases such as “unprecedented” and “100-year event”, the report says.

Policy and funding mechanisms should be changed so homeowners do not defer property maintenance and exacerbate the damage caused in flood events. 

The report calls for increased homeowner education and risk awareness.