Nassau County seawall guide.
Big tides and protected marsh.

Permit offices

• City of Fernandina Beach: Building Department, City Hall, 204 Ash Street, 904-310-3135.
• Unincorporated Nassau County: Building Department, 96161 Nassau Place, Yulee, 904-530-6250, with permits through an online Accela portal.
• Floodplain management: 904-530-6410; the county’s flood page links an address-searchable flood map.

Permits · Building Department · Know Your Flood Hazard

Tides and storms

The Fernandina Beach gauge shows a daily range of about 6.6 feet. Its highest listed crests are 6.94 feet above normal high water in 1898 and 4.13 feet in Matthew (2016). The Nassau River gauge near Tisonia peaked at 4.52 feet in Irma.

Fernandina Beach 8720030 datums · NWPS gauge FRDF1 – Atlantic Coast at Fernandina Beach · NWPS gauge NATF1 – Nassau River near Tisonia

Aquatic preserves

Fort Clinch State Park Aquatic Preserve and the Nassau River–St. Johns River Marshes Aquatic Preserve lie in Nassau County. Inside them no new seawalls may be built waterward of the high-water line, and the waters are Outstanding Florida Waters.

s. 258.39, F.S. – Boundaries of preserves (2026) · Rule 18-20.004, F.A.C. – Aquatic Preserve Management Policies, Standards and Criteria · Rule 62-302.700, F.A.C. – Special Protection, Outstanding Florida Waters

Beach work

The Nassau County Shore Protection Project renourished Fernandina Beach in 2025 with about 750,000 cubic yards of sand. Oceanfront armoring follows Florida’s coastal control-line rules.

Fernandina Beach sand placement complete · Chapter 62B-26, F.A.C. – Coastal Construction Control Lines

Flood insurance discounts

Fernandina Beach is CRS class 5 (25% NFIP discount); unincorporated Nassau County is class 7 (15%). Callahan and Hilliard are not on FEMA’s current list.

CRS Eligible Communities, October 1, 2026 Effective Date