Miami-Dade County, Florida
A shallow water table limits basements on 55% of Miami-Dade County's mapped land, a higher share than 71% of US counties. Shrink-swell clay limits houses without basements on 1%.
The soil survey maps 58% of the county's land area; these shares describe the mapped part. 29% of the county is in drought on the November 3, 2026 Drought Monitor map, down from 72.5% a week earlier. FEMA's flood data list 7,815 flood losses here since 2016, 4% of them in buildings with basements. 50% of homes were built before 1980, against 50% nationally; the median home dates from 1980.
Data as of November 3, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, November 3, 2026
of homes built before 1980
Soil under Miami-Dade County
| Expansive clay (limits slab homes) | 1.1% |
| High water table (limits basements) | 55.3% |
| Septic fields very limited | 57.3% |
| Clay swell (LEP, by area) | 0.2% |
| High-swell land (LEP 6%+) | 0.0% |
| Urban land, not rated | 24.2% |
| Mapped soil | 703,300 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Biscayne | 9% | n/a |
| Krome | 7% | n/a |
| Perrine | 6% | n/a |
| Shark Valley | 6% | n/a |
| Cooper Town | 4% | n/a |
| Chekika | 4% | n/a |
How we count · survey areas FL624 (2025-09-02), FL686 (2025-08-29)
What the numbers mean here
On 55% of Miami-Dade County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 44.50 in, 13.02 in below the 1991-2020 average year of 57.52 in.
USDA rates 57% of the land very limited for septic absorption fields.
Drought
29% of the county is in drought (D1 or worse) on the November 3, 2026 map. Part of the county was in drought in 51 of the last 52 weeks; the most was 100% of its area, in 17 weeks, most recently on the September 15, 2026 map.
| Category, November 3, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 50.3% |
| D1 moderate drought or worse | 29% |
| D2 severe or worse | 17% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
7,815 flood losses since 2016, $259.8 million paid. The worst year was 2017, with 4,100. Foundations of the buildings, where recorded: 4% basements, 80% slabs, 9% crawl spaces, 8% elevated. Median water depth outside the building: 9 in.
| Year | Flood losses |
|---|---|
| 2016 | 86 |
| 2017 | 4,100 |
| 2018 | 88 |
| 2019 | 274 |
| 2020 | 1,526 |
| 2021 | 78 |
| 2022 | 349 |
| 2023 | 332 |
| 2024 | 864 |
| 2025 | 90 |
| 2026 to date | 28 |
Rain
| Average year, 1991-2020 | 57.52 in |
| 12 months to August 2026 | 44.50 in (-13.02) |
| 2025 | 44.87 in (-12.65) |
| Wettest year since 1895 | 1959: 77.68 in |
| Driest year since 1895 | 1956: 34.86 in |
| Days with 1 inch or more, normal at PERRINE 4W (5 mi away) | 20.2 |
Homes
| Housing units | 1,094,983 |
| Median year built | 1980 |
| Built before 1980 | 50% |
| Built 2000 or later | 24% |
| Owner-occupied | 52% |
| Median value, owner-occupied | $463,000 |
| Single-family detached | 39% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Monroe County, FL | 32 mi | n/a | n/a |
| Broward County, FL | 40 mi | under 1% | 83% |
| Collier County, FL | 64 mi | 0% | 82% |
| Palm Beach County, FL | 72 mi | 0% | 84% |
| Hendry County, FL | 76 mi | 0% | 98% |
| Martin County, FL | 102 mi | under 1% | 75% |
| Glades County, FL | 102 mi | 0% | 75% |
| Lee County, FL | 113 mi | 0% | 59% |
Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (November 3, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status