The Union of Concerned Scientists (UCS) just released a new report warning that rising sea levels from global warming could increase flooding during high tides on the East Coast and Gulf Coast of the United States — potentially tripling flood events in 15 years and inundating coastal communities with a ten-fold increase in 30 years. The study, ominously titled “Encroaching Tides,” analyzed 52 National Oceanic and Atmospheric Administration (NOAA) tide gauges in Atlantic and Gulf cities stretching from Portland, Maine to Freeport, Texas. The study projects that by 2030, more than half of the 52 communities will experience, on average, at least 24 tidal floods per year and by 2045, most of the towns would see at least 48 floods at high tide each year. At least nine of those communities are expected to experience a whopping 240 tidal floods per year in 30 years, when sea levels are expected to rise at least one foot.


tidal flooding, high-tide floods, rising sea levels, global warming, climate change

The study projects that mid-Atlantic communities will bear the brunt of tidal floods because, in addition to rising sea levels, “the land is sinking and ocean dynamics are changing.” In 30 years, Washington, D.C.; Annapolis, Maryland; Lewisetta, Virginia; and Wilmington, North Carolina will see well over 300 flooding events per year. The New Jersey coast is also very vulnerable, with Atlantic City and Cape May among the nine communities that could see tidal flooding 240 times or more per year. Without adaptation efforts, in 15 years many of the floods in the Atlantic City area could close the roads linking West Atlantic City to the mainland. Florida is also in for trouble, where Miami Beach would see more than 200 tidal floods per year by 2045, threatening the art deco historic district of South Beach.

Related: Rising Sea Levels Could Submerge 1,700 U.S. Cities by 2100

“This report shows that, within the timeframe of a 30-year mortgage, many East Coast communities will see dramatic changes in the number and severity of tidal floods each year, unless, of course, successful steps are taken to manage those floodwaters,” said Erika Spanger-Siegfried, co-author of the report and senior analyst at UCS.

The report recommends that threatened communities prioritize mitigation and adaptation initiatives with state and federal help, including flood-proofing homes and neighborhoods, hardening key infrastructure and restricting development in areas subject to tidal flooding. The study also recommends considering the risks and benefits of adaptation measures such as sea wall and natural buffers and making long-term, science-based plans to prepare for an increase in high-tide flooding.

+ Encroaching Tides

+ Union of Concerned Scientists

Via Union of Concerned Scientists

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