The threat of flooding is increasing in every region of the United States as a warming atmosphere makes precipitation events more extreme and contributes to sea-level rise. Floods are the costliest natural disaster threat in the nation, accounting for at least $845 billion in losses since 2000.

Even though every US region is at risk of costly flooding, only 10 states require the disclosure of flooding history at the time of a home purchase. Without robust requirements to disclose flood risks, potential homebuyers don’t have all the information they need to make a safe and wise decision on a major financial investment.

Today, a homebuyer could visit the Federal Emergency Management Agency’s (FEMA’s) Flood Map Service Center to see whether a prospective home is in a floodplain, but new calculations that account for sea-level rise, rainfall, and flooding along small creeks find an underestimation of flood risk is a nationwide problem. An additional 5.7 million properties beyond those in FEMA flood maps are in a 100-year floodplain. Yet most states don’t require a seller to detail a home’s history of flooding.

No federal law requires natural hazard risk disclosures, despite 74 percent of Americans supporting such a requirement. In the absence of a federal mandate, some states have set their own hazard disclosure regulations. Two years after Hurricane Harvey, Texas became the latest in a now majority of states to require basic disclosure of whether a home lies in a floodplain. Texas has gone a step further by requiring sellers to disclose whether there had been any previous flood damages on a property and how much insurance money the previous owners received.

Regardless of the quantifiable impacts of robust flood disclosure, buyers have a right to fairness and honesty when making one of the biggest financial investments of their lives. Clear communication of risk, knowledge of options to mitigate disasters, and access to resources could go a long way in empowering homebuyers to protect themselves against catastrophic hazards and make them unwilling to accept risk.

By strengthening or better enforcing state and federal requirements to disclose basic flood risk, policymakers can enhance buyers' bandwidth to understand risks, act on those risks, and combat other pressures and issues of distributive injustice they experience when purchasing a home.

Read the full article about requiring disclosure of natural disaster risks by Rebecca Marx, Clare Salerno, and Carlos Martín at Urban Institute.