Jump to main content.

Governments Plan for Development of Land Vulnerable to Rising Sea Level: Northeast Florida

Excerpts from Northeast Florida sea level rise planning study by Maurice Postal, Baker County (formerly with Northeast Florida Regional Planning Council)

Our assessment of Northeast Florida's response to sea level rise includes six counties: Clay, Duval, Flagler, Nassau, Putnam, and St. Johns. The study area consists of approximately 321 square miles of uplands and 254 square miles of wetlands, which is all of the land below the 10-foot contour. This area accounts for 14 percent of these six counties.

Table 1 illustrates the breakdown of the various land uses in the study area. Because Northeast Florida is still largely undeveloped, conservation lands make up the single largest land use that would be affected by sea rise. This category makes up 38 percent (183 square miles) of the upland study area. The next largest upland area is residential use, comprising 26 percent (145 square miles) of the study area. Agricultural use is the third largest category, taking up 23 percent (134 square miles) of the affected area. Public/recreational, commercial, and industrial land use categories together encompass only 13 percent (67 square miles) of the area affected by rising seas.

Table 2 summarizes the area of land in the various shore protection likelihood categories. Wetlands make up almost half (47 percent) of the total study area (254 square miles). We estimate that protection is almost certain for about 55 percent (176 square miles) of the dry land within the study area. The Atlantic Coast of Florida continues to be developed, and it can be expected that residential areas will be protected. As a result, shore protection is likely for another 89 square miles (28 percent) of the dry land in the study area. Thus, under current policies, more than 80 percent of the dry land is likely to be protected from rising sea level.

Lands where shore protection is unlikely cover 42 square miles of the study area, about 13 percent of the dry land. Conservation lands and other areas designated as no protection account for 14 square miles, only 4.4 percent of the dry land in the study area. Thus, the areas where wetlands are likely to migrate inland account for only 18 percent of the study area (56 square miles).

The ultimate net loss of wetlands by any particular year will depend both on landward migration and on the ability of wetlands to keep pace with sea level rise. Nevertheless, in the very long run, existing tidal wetlands would be submerged by a large rise in sea level and thus their continued existence depends on new wetlands forming inland. Viewed in that light, existing policies are almost certain to eliminate about 55 percent the wetlands that might otherwise be sustained as sea level rises and to protect 4percent of those wetlands. We are less certain about the other 41percent. There appears to be a good chance that wetlands will migrate land in another 13 percent of the region, and wetland migration is possible albeit unlikely in 28 percent of the region. Planners need guidance from both scientists and policy makers about the importance of ensuring that wetlands survive in the areas our maps depict in blue and red, compared with the benefits of preventing wetlands from taking over these areas.

For additional details, please see summaries for Clay, Duval, Flagler, Nassau, Putnam, and St. Johns counties.

Top of page

Governments Plan for Development of Most Land Vulnerable to Rising Sea (PDF, 7 pp., 1.3 MB) was originally published in Environmental Research Letters , Issue 3, Volume 4 (2009).

Top of page

| Main study | Elevation Maps | Zipped file of the maps Related Links

Local Navigation

Jump to main content.