As long-time, year-round coastal residents can attest, coastal landscapes are forever changing, and many places that seemed safe for building 10 years ago are now regularly underwater during minor storms. Many sources now predict that the frequency and power of storms will increase in the future. When using coastal flood data, especially Flood Insurance Rate Maps (see understanding the limitations of Flood Insurance Rate Maps and Flood Insurance Study reports), be sure to consider future flooding scenarios. Your community may also wish to include accommodations for future coastline changes and effects of sea-level rise, subsidence, or increased development in the floodplain in its regulatory language. (For example, prohibiting the construction of new buildings in areas where they are likely to be threatened by erosion during their design lives.)
See the following resources for information on future coastal conditions:
- Preparing for Climate Change: A Guidebook for Local, Regional and State Governments is a detailed study on how local governments can best adapt and respond to climate change.
- For an example of a (Massachusetts) bylaw incorporating projected sea level rise, see this Model Floodplain District Bylaw.
- For information on Florida regulations, see this Department of Environmental Protection page.
- The Mississippi Department of Environmental Quality’s Coastal Geology Section website provides detailed shoreline change maps and GIS data showing the relative positions of historic shorelines, along with information on how to interpret these maps and data. Shoreline change and other spatial data are also available from the Mississippi Department of Marine Resources, and The United States Geological Survey (USGS) National Assessment of Shoreline Change Project.
- The Bureau of Economic Geology Texas Shoreline Change Project provides shoreline change maps and GIS data showing the relative positions of historic shorelines, along with information on how to interpret these maps and data. Shoreline change for each coastal community in Texas. Other spatial data are also available from the United States Geological Survey National Assessment of Shoreline Change Project.
* Your community needs only 500 points to qualify for reduced flood insurance premiums through the Community Rating System (CRS). For more information (including how to apply for the CRS program), see our Community Rating System (CRS) primer.
Notes from the folks at CRS:
“Coastal erosion mapping and setback regulations are one way coastal communities protect property from future conditions and is creditable under a number of elements in the CRS: see 410 MCE, 420 CEOS, 430 CER, and 440 EDM.”