New Floodplain Lines Released!


Highlights from Steven Gonzales on redefining the floodplain lines which determine who needs to own FEMA flood insurance.

  • Steve presented two boards showing the revised map – see images below.
  • The new topography data was collected at 2’ height intervals – 5 times more accurate than the data used for existing 1970s version
  • Technically, 100 year storms are called 1% chance storms and 500 year storms are referred to as .2% chance storms
  • Calculations were done based on Complete Impervious Buildout in the catch basin.
  • The FEMA public commenting process will most likely begin some time after September
  • There will be a 90 day appeal process. Appeals will only be based on scientific calculations – not first person accounts of past events.
  • FEMA backed flood insurance is passed with the property, not with the owner. Once you purchase a level of insurance, those rates are locked – unless you decide to upgrade your plan.
  • Insurance companies should not be allowed to use the new maps for rate determination until the final has been issued by FEMA.
  • Sections through the river are taken every 1000’
  • All information on the new floodplain maps can be found at

If you’re concerned about how the floodplain issue may affect your property, please contact a member of the RRNA Drainage Committee.

I’ve attached several low to high quality scans of the presentation boards, just click on this article’s title.

This image was taken from the website – only the pink tone has been added for clarity.

Flood Map from Site

This image was scanned from the board presented at the board meeting – only the pink tone has been added for clarity.

middle size map


The link below is only good if you wish to see some of the detail in areas around River Road. It won’t make the lines in the neighborhood any clearer than the above images.

Big Zip File

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