#Fema flood zones florida update#

But as pointed out in Madison Condon’s excellent 2023 essay, Climate Services: The Business of Physical Risk, the nonprofit Flood Coalition cautions that “while First Street Foundation’s nationwide data is useful for ‘risk awareness,’ it is not a substitute for detailed property-level stormwater modeling, and should not be used in regulatory decision making. Risk Factor from the nonprofit First Street Foundation provides the most-used freely available tool for determining climate risk of an individual property. So buyer beware! These tools are new and unproven, and rely on data that is not publicly available and use methods that are often “black boxes.” I was only able to perform a cursory check of these tools, and an in-depth evaluation could well reveal major flaws. As an article by Lee Harris in the American Prospect warned, beware of “risk modelers who are selling precision in an inherently imprecise business, and formulating questions that sound technical but convey little meaningful information.” Though these new companies are providing valuable information, the industry has a bit of a Wild West feel.

The back story: There’s a huge demand for information on climate change risks of all kinds, including flooding, and a new industry has sprung into being to provide these ratings. The best tools for a quick overview of your property’s flood risk: Risk Factor, Risk Factor Pro, ClimateCheck 1).Ī 2020 study by the First Street Foundation, though based on an older version of the flood model, has detailed state-by-state pages of flood risk. For example, Houston’s Harris County is now estimated to experience what FEMA calls a 1-in-100-year flood event every 13 years (Fig. The Washington Post published a searchable table in June 2023 that allows you to view the report’s change in 1-in-100-year flood events. rain gauges from the past 20 years done by the nonprofit First Street Foundation. properties at risk of 1-in-100-year flooding is a factor of 2.2 higher than FEMA flood maps show, according to a 2023 analysis of NOAA’s 795 continental U.S. (Image credit: First Street Foundation)īecause FEMA is not using the most recent rainfall statistics, which show a sharply increasing risk of heavy precipitation events in the past 20 years, the number of contiguous U.S. Areas in white have not seen an increase in risk of a 1-in-100-year flood (and in some cases, have seen a decrease), while areas in blue have seen increased flood risk. The corrected return period of a FEMA-defined 1-in-100-year flood using an updated version of NOAA precipitation statistics which accounts for an increase in heavy precipitation events in the past 20 years. This is an increasingly common type of flooding in urban areas that have been extensively paved over when climate change-boosted extreme rainfall events dump huge amounts of water on regions that drain poorly.įigure 1. FEMA maps do not factor in climate change and also do not account for the risk of “pluvial” floods.

#Fema flood zones florida update#

They are often out of date, available only as decades-old paper maps in some locations, and many local governments oppose efforts to update the maps for fear that it will depress property values and discourage development. Is the data good? FEMA maps have significant problems. If you are within a FEMA 1-in-100-year flood risk area, you could assume there is at least a 26% chance of a 1-in-100-year flood occurring over the span of 30 years. If you are in a FEMA 1-in-100-year flood risk area, you will be required to buy flood insurance from the National Flood Insurance Program in order to secure a federally backed mortgage. What it does: These maps show the expected 1-in-100-year and 1-in-500-year flood risk areas, which are regions that have a 1% per year and 0.2% per year chance of flooding, respectively.

The back story: The traditional way to know your flood risk has been to consult the latest Federal Emergency Management Agency (FEMA) flood map through its Flood Map Service Center.