NOAA 2014 State of Nuisance Flooding

The National Oceanic and Atmospheric Administration's (NOAA's) 2014 State of Nuisance Tidal Flooding highlights nuisance flood frequencies during the 2014 meteorological year, May 2014 through April 2015, at 27 NOAA tide stations around the U.S. which have collected data for more than 50 years.

The study defines nuisance tidal flooding as a daily rise in water level above minor flooding thresholds set locally by NOAA weather forecasters and emergency managers for coastal areas prone to flooding. Nuisance flooding causes public inconveniences such as frequent road closures, overwhelmed stormwater systems, and compromised infrastructure. The extent of nuisance flooding depends on multiple factors, including topography, land cover, and sea level rise.

The study found that the mid?Atlantic coast was most impacted in the 2014-2015 timeframe. Between Sandy Hook, New Jersey and Savannah, Georgia long?term accelerating trends continued unabated with several locations reporting 20 or more days of flooding and an increase from 2013. Topping the list, Wilmington, North Carolina experienced 71 days of nuisance flooding; Annapolis, Maryland 41 days; and Charleston, South Carolina and Washington D.C. both with 33 days. The West Coast experienced a more modest number of days with nuisance flooding. Very few days with nuisance flooding were recorded along the U.S. Northeast and Gulf Coasts, which is partially related to the fact that these regions have higher nuisance flood levels to begin with (see Figure 1 for more information).

The report gives an outlook for the 2015 meteorological year that considers historical flooding trends and differences typical during El Niño. For instance, these nuisance flooding projections are based on trends that factor in El Niño:

• Norfolk, Virginia, experienced eight nuisance flood days during the 2014 meteorological year. It may experience 18 days in meteorological year 2015 with El Niño, a 125 percent increase over the projected eight days.
• Atlantic City, New Jersey, had 21 nuisance flood days in meteorological year 2014. It may experience 36 days in meteorological year 2015 with El Niño, a 33 percent increase over the projected 27 days.
• San Francisco, California, had 11 nuisance flood days during meteorological year 2014. It may experience 21 days during meteorological year 2015 with El Niño, a 75 percent increase over the projected 12 days.


 

Publication Date: September 9, 2015

Authors or Affiliated Users:

  • William V. Sweet
  • John J. Marra

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Resource Types:

  • Assessment
  • Tool (general)

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