The way the federal government analyzes intense rain events isn’t keeping up with the reality of climate change, and that has serious implications for infrastructure projects and the availability of, and rising cost of, flood insurance.
Severe rainstorms, sometimes described as “atmospheric rivers” or “torrential thunderstorms,” are making the concept of a “1-in-100-year flood event” obsolete, according to a report from First Street Foundation, an organization focused on weather risk research.
These events are occurring more frequently due to the impact of climate change, but federal rainfall analysis, managed by the National Oceanic and Atmospheric Administration, isn’t keeping up with the new weather conditions, First Street says.
Half the people in the U.S. live in a county where a 1-in-100-year flood is at least twice as likely now as it had been in the past, coming once every 50 years instead of every 100 years. In some areas, a so-called “1-in-100-year” rainfall could now happen far more frequently—as often as every 5 to 10 years.
The outdated analysis has serious implications for the way infrastructure projects are initiated and designed. And, because FEMA’s federal flood insurance program greatly underrepresents the number of people that could fall into FEMA’s Special Flood Hazard Areas, millions of Americans may be unaware of their current flood risk.
Inaccurate flood risk data due to underestimating the impact of rainfall also impacts the cost and availability of flood insurance—this is especially true for property that isn’t close to the ocean or inland bodies of water.
The government is working to remedy the situation, though. NOAA, as reported by CNN, says it is working on a revamped approach to its rainfall analysis that is expected to be completed in 2027.
Related Stories
Codes and Standards | Oct 16, 2015
Appellate court enacts nationwide stay on controversial expansion of Clean Water Act
New EPA rule suspended until court cases settled.
Codes and Standards | Oct 9, 2015
New California law means commercial building benchmarking program will be implemented
Multifamily housing to be included, a first for a U.S. state.
Codes and Standards | Oct 2, 2015
New ASHRAE guideline for commissioning existing systems and assemblies
Focuses on optimum facility and system operation.
Codes and Standards | Sep 18, 2015
New RELi standard addresses disaster resilience
Based on LEED model, may help lower insurance rates
Building Materials | Aug 28, 2015
Structural steel buildings specification available for second public review
Next year's specification open for comments until Sept. 21
Energy Efficiency | Aug 28, 2015
North American Passive House Network e-book explains Passivhaus, net-zero techniques
Free guide includes spotlight on individual projects
Windows and Doors | Aug 28, 2015
Newly formed group challenges Florida building code
Window, door companies oppose provisions that raise costs
Codes and Standards | Aug 28, 2015
New Orleans becoming a model for climate resilience only 10 years after Katrina
The city has moved ahead with resilience strategies that may become a model for other communities
Codes and Standards | Aug 21, 2015
Illinois governor vetoes bill that would restrict condo owners’ rights
Bill would have made it harder to sue for building flaws
Codes and Standards | Aug 21, 2015
Post-Katrina roofing codes creating more resilient buildings on Gulf Coast
Ten years after storm, notable progress on stronger roofs, IBHS says