"Seawater on the streets.” One immediately knows that, notwithstanding the alliterative allure, something is not right. And when one is in Annapolis, Maryland, and the Alex Haley Scuplture Group is literally reading in the waves, it is plain disconcerting. The National Oceanic and Atmospheric Administration calls this “nuisance flooding,” and has just issued a report,Sea Level Rise and Nuisance Flood Frequency Changes around the United States, that takes sea level rise down to the day-to-day and documents the quotidian, long-term repetitive inundations that are regularly besetting portions of the American littoral. Annapolis and its sometimes aquatic sculpture grace the cover of the report and also top the list of areas experiencing the most increase in nuisance flooding.
The report is based on the National Water Level Observation Network (NWLON), whose gauges have been monitoring tides for decades, even, in many cases, nearly a century. NOAA scientists have applied their expertise and formulae and provided valuable results. The report is quite technical. For example, “[t]rends derived from linear regression on the annual number of nuisance flood days are statistically significant at the 90% level at 41 of the 45 gauges analyzed.” Report at 9-10. However, while the Report may be technical, the graphs are plain. Even non-technical people can understand the scatter plots showing an accelerating trend of nuisance flooding or the bar charts that show the increase in annual days of flooding.
Where is this increase occurring, and when? The Report identifies the Mid-Atlantic, Chesapeake Bay, North and South Carolina and southern Texas as experiencing a higher value of “nuisance flood days” – greater than 20 annually. Report at 9. By way of comparison, in the 1950s the frequency of nuisance flooding across the United States (the return period) was of the order of 1-5 years. Today “the probabilities of a nuisance flood event have increased throughout much of the U.S., with return periods typically <0.25 year (3 months) at most NOAA gauges.” Report at 16. Besides Annapolis, areas recently suffering over 20 nuisance flood days on average per year include Atlantic City and Sandy Hook, N.J., Charleston, S.C., and Washington, D.C.
The significance of this is easy to visualize: “overwhelmed stormwater drainage capacity, frequent road closures, and general deterioration and corrosion of infrastructure not designed to withstand frequent inundation or salt-water exposure.” Report at vi.
But there are other more subtle impacts. Nuisance flooding immerses a community in a rising sea level. That may prompt a review of coastal property boundaries and, because the State owns the land below mean high water (or, in some cases, mean low water), a transfer of property to the State with the accompanying effect on tax base and property ownership may materialize with substantial impact on the community. Even without a redrawing of property lines, properties subject to increased flooding are likely to lose value, reducing or eliminating nest eggs, retirement security and loan collateral. In such circumstances, transaction professionals (lawyers, real estate agents) may wish to evaluate the disclosures their client sellers need to make and the warranties their client buyers should require.
Rising sea levels are bringing the ocean into areas it used to avoid. The new bucket list for some destinations may literally mean to bring a bucket.