Martin County, Florida
A shallow water table limits basements on 75% of Martin County's mapped land, a higher share than 85% of US counties. Shrink-swell clay limits houses without basements on under 1%.
23.7% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 264 flood losses here since 2016, 1% of them in buildings with basements. 34% of homes were built before 1980, against 50% nationally; the median home dates from 1986.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Martin County
| Expansive clay (limits slab homes) | 0.3% |
| High water table (limits basements) | 74.7% |
| Septic fields very limited | 78.4% |
| Clay swell (LEP, by area) | 1.8% |
| High-swell land (LEP 6%+) | 0.3% |
| Mapped soil | 425,700 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Riviera | 11% | n/a |
| Wabasso | 8% | n/a |
| Pineda | 6% | n/a |
| Waveland | 5% | n/a |
| Oldsmar | 5% | n/a |
| Immokalee | 4% | n/a |
How we count · survey areas FL085 (2025-08-29)
What the numbers mean here
On 75% of Martin 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: 48.41 in, 7.17 in below the 1991-2020 average year of 55.58 in.
USDA rates 78% of the land very limited for septic absorption fields.
Drought
23.7% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 48 of the last 52 weeks; the most was 100% of its area, in 22 weeks, most recently on the June 9, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 40.7% |
| D1 moderate drought or worse | 23.7% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
264 flood losses since 2016, $3.9 million paid. The worst year was 2020, with 60. Foundations of the buildings, where recorded: 1% basements, 86% slabs, 3% crawl spaces, 10% elevated. Median water depth outside the building: 7 in.
| Year | Flood losses |
|---|---|
| 2016 | 39 |
| 2017 | 53 |
| 2018 | 21 |
| 2019 | 10 |
| 2020 | 60 |
| 2021 | 7 |
| 2022 | 53 |
| 2023 | 6 |
| 2024 | 8 |
| 2025 | 6 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 55.58 in |
| 12 months to August 2026 | 48.41 in (-7.17) |
| 2025 | 43.01 in (-12.57) |
| Wettest year since 1895 | 1994: 80.68 in |
| Driest year since 1895 | 2006: 36.49 in |
| Days with 1 inch or more, normal at STUART (12 mi away) | 18.7 |
Homes
| Housing units | 83,121 |
| Median year built | 1986 |
| Built before 1980 | 34% |
| Built 2000 or later | 24% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $432,200 |
| Single-family detached | 54% |
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 |
|---|---|---|---|
| St. Lucie County, FL | 21 mi | 0% | 89% |
| Palm Beach County, FL | 30 mi | 0% | 84% |
| Okeechobee County, FL | 37 mi | 0% | 85% |
| Indian River County, FL | 43 mi | 1% | 90% |
| Glades County, FL | 50 mi | 0% | 75% |
| Hendry County, FL | 60 mi | 0% | 98% |
| Highlands County, FL | 61 mi | 0% | 80% |
| Broward County, FL | 62 mi | under 1% | 83% |
Sources: USDA SSURGO (August 29, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status