With sea level rise continuing to accelerate along the Atlantic and Gulf coasts, Virginia coastal communities in 2019 saw two to five times more nuisance flooding than the national average, a federal report released this week shows.
“Evidence of a rapid increase in sea level rise-related flooding started to emerge about two decades ago, and it is now very clear,” the report from the National Oceanic and Atmospheric Administration says. “This type of coastal flooding will continue to grow in extent, frequency and depth as sea levels continue to rise over the coming years and decades.”
But while the national frequency of nuisance flooding — a measure that combines frequency measurements from all U.S. coastal tidal gauges — was four days in 2019, such flooding occurred in Virginia last year anywhere from nine days in Kiptopeke on the Eastern Shore to 20 days at Lewisetta on the Northern Neck.
In between, Wachapreague on the Eastern Shore saw 13 days of nuisance flooding, Sewells Point in Norfolk experienced 14 days and Windmill Point in Hampton saw 17 days.
All of the measurements, both nationally and within Virginia, far exceed totals from the year 2000, when they hovered around two days nationally and between two and five days in the commonwealth.
“Flooding that decades ago happened only during a severe storm can now occur during a full-moon tide or with a change in prevailing winds or currents,” the NOAA report concludes.
This type of flooding, most commonly called high-tide, nuisance or sunny-day flooding, is often readily apparent to most residents of a community.
“It’s the flooding that’s showing up and clogging storm gutters and spilling into roads and that people are having to drive through,” said NOAA oceanographer and report co-author Billy Sweet.
It’s also rapidly becoming the new normal as high-tide flooding and sea level records are routinely broken along the Atlantic Coast.
Both Lewisetta and the Hampton tide gauges broke records for number of nuisance flooding days in 2019, while NOAA reported that new records for sea level rise were set at 57 of 62 East and Gulf Coast locations.
“Water is quickly approaching the brim in many of these communities, and additional disturbances really create a number of extra days” of high-tide flooding, said Sweet.
NOAA predicts that 2020 nuisance flooding will be roughly the same as in 2019, even as over the long term the phenomenon gets worse. Absent any policy efforts to mitigate flooding, such as slowing the pumping of water from aquifers that causes land subsidence or wetlands preservation that can absorb and slow waves, NOAA predicts that the Virginia coast could see between 10 and 25 days of nuisance flooding by 2030 and as many as 170 days in certain areas by 2050.
Many local governments in Hampton Roads in particular have already taken steps to prepare for sea level rise evident throughout the region. As the Virginian-Pilot reported last month, the Virginia Beach City Council recently approved a sea level rise plan that was six years and almost $4 million in the making. Norfolk has revamped zoning ordinances. Hampton is exploring solutions such as blueways that seek to work with floodwaters rather than resisting them.
Sweet emphasized that the data reported by NOAA and used in its forecasts is drawn from the same tidal gauges used for a century by not only scientists but shipping businesses and the military.
“Folks depend on this and they’ve been depending on this data for 100 years,” he said. “And now this data is telling us another story.”