Coastal communities in the U.S. continued to see record-setting high-tide flooding last year, forcing their residents and visitors to deal with flooded shorelines, streets and basements — a trend that is expected to continue into 2021.
NOAA’s 2019 State of High-Tide Flooding and 2020 Outlook reports that evidence of a rapid increase in sea level rise-related flooding started to emerge about two decades ago and it is now very clear that it will continue to grow over the coming years and decades. In the report you will find:
- Changes in high-tide flooding patterns from May 2019 to April 2020 at 98 NOAA tidal gauges along the U.S. coast
- Flooding outlook for those locations for the coming meteorological year, May 2020 to April 2021
- Projections for the next several decades
High-tide flooding, often referred to as “nuisance” or “sunny day” flooding, is increasingly common due to years of relative sea level increases. It occurs when tides reach anywhere from 1.75 to 2 feet above the daily average high tide and start spilling onto streets or bubbling up from storm drains. As sea level rise continues, damaging floods happen more regularly during a full-moon tide or with a change in prevailing winds or currents.
NOAA projects that from May 2020 to April 2021, the national high tide flood frequency is expected to accelerate, with U.S. coastal communities seeing an average of 2 to 6 days of flooding in the coming year. Communities along the northeast and western Gulf coasts are projected to see even more days of flooding.
By 2030, long-term projections show seven to 15 days of high-tide flooding for coastal communities nationally. By 2050, that rises to 25 to 75 days, suggesting high tide flood levels may become the new high tide.
NOAA maintains ocean observing infrastructure in more than 200 permanent water level stations on the U.S. coasts and Great Lakes.
Find your local water level station here: NOAA Tides and Currents
Source: Insurance Journal