Half of Miami-Dade's properties sit in a mapped flood hazard area

Miami-Dade County publishes a service that attaches the federal flood zone to every property record in the county. We read it directly: 923,140 parcels, each carrying its FEMA zone, storm-surge scores for 2040 and 2070, sea-level-rise grid codes and the owner of record.

470,652 of those parcels — 51.0% — sit inside a FEMA special flood hazard area (zones that begin with A or V). The rest split into 452,237 parcels in zone X, outside the hazard area, 222 in zone D (studied but undetermined), 26 recorded as open water and 3 with no zone at all.

The hazard is not uniform. 273,966 parcels (29.7%) are in zone AE, the coastal and riverine areas with detailed depth analysis. 177,427 (19.2%) are in AH, where shallow flooding is the defining risk. 5,016 are in VE, the coastal high-hazard strip where waves are expected — the most expensive place to build, insure or keep a property.

By municipality the pattern is stark. Key Biscayne has all 7,376 of its parcels inside the hazard area. Aventura has 25,125 of 25,336 (99.2%). Miami Beach has 52,699 of 56,804 (92.8%). Miami Lakes is 90.0%. The city of Miami carries the largest raw count — 60,967 parcels, 44.2% of its 137,956 — while the unincorporated county holds 182,558 of 384,928 (47.4%). Coral Gables, at 22.6%, and Hialeah Gardens, at 8.8%, show how quickly the picture changes across a county line.

Why ReFrame treats this as a displacement issue. Flood zone is a cost, not a forecast. Zone designation drives insurance requirements, retrofits and lease terms, and households that cannot absorb those costs — often renters, often older, often in the highest-exposure neighborhoods — are the ones who move first. The county's own records let a neighborhood association name the exposure on its own block instead of arguing from memory.

Limitations. Parcels are not households: a single parcel can hold a fourplex or a condo building, so these counts measure land and structures, not people. FEMA zones describe mapped hazard, not damage history or real-world flooding, and they are revised on their own schedule — a zone on this data pull can change with the next map update. Zone AH means shallow flooding and VE means wave action; both are averages that hide street-by-street detail. The county's service is public and needs no key, so any of these numbers can be re-run by anyone from the same endpoint we used.