An island suburb that quadrupled in a decade
Wilmington Island is an unincorporated community between Thunderbolt and Tybee Island, bordered by the Wilmington River on one side and the Bull River on the other, sitting at 10 feet of elevation across 9.65 square miles. Its growth was explosive by service-area standards: from 3,284 residents when it first appeared as its own census count in 1970 to 7,546 by 1980 and roughly 15,000 by 2010, where the population has largely held since (15,129 in the 2020 census).
What that means for a foundation evaluation
Because most of Wilmington Island's housing was built during that 1970s-through-2010 growth surge, foundations here are overwhelmingly modern construction on river-bordered, low-lying ground — the same high-water-table coastal-plain soil found across the service area, but with two tidal rivers bracketing the island instead of one. An evaluation should weigh riverfront grading and drainage on these newer homes rather than assume century-old settlement, which is uncommon on an island built out this recently.
Next steps for Wilmington Island
What a Wilmington Island inquiry should cover
Include the issue you're seeing on the Wilmington Island property, when it started, the home's age, prior foundation work, and access between the two rivers bordering the site. Provider availability varies, so confirm credentials before hiring.
Two rivers, one shallow water table
Wilmington Island's position between the Wilmington River and the Bull River puts it on some of the lowest, wettest ground in the service area at just 10 feet of elevation — conditions that reinforce the same regional pattern of slab-on-grade and raised crawl-space construction found from Savannah's historic core out to the barrier islands.