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Los Fresnos, Texas
Inside Los Fresnos' city limits, shrink-swell clay limits houses without basements on 45% of mapped land, the 5th-highest of 19 cities in Cameron County. A shallow water table limits basements on 10%.
That clay share is above Cameron County's 29%. FEMA's flood data list 22 flood losses since 2016 in ZIP code 78566 overlapping the city. Of its 2,600 homes, 27% were built before 1980; the median dates from 1999.
Data as of October 13, 2026 · sources · in Cameron County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 1 overlapping ZIP
of homes built before 1980
Foundation repair in Los Fresnos
Foundation repair in Los Fresnos: shrink-swell clay limits slab homes on 45% of Los Fresnos' mapped land, more than in 53% of Texas cities.
About 2,000 of Los Fresnos' 2,600 homes are detached houses.
| Who designs the repair | The ASCE Texas Section's repair guidelines say a Texas-licensed engineer should evaluate the foundation and design the repair (2022 guidelines) |
| Prices | Cost guide ranges compared |
Soil under Los Fresnos city limits
| Expansive clay (limits slab homes) | 44.5% |
| High water table (limits basements) | 10.5% |
| Septic fields very limited | 52.4% |
| Clay swell (LEP, by area) | 11.2% |
| High-swell land (LEP 6%+) | 48.9% |
| Urban land, not rated | 3.5% |
| Mapped soil | 2,924 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Laredo | 36% | 0% |
| Harlingen | 28% | n/a |
| Olmito | 11% | n/a |
| Benito | 6% | n/a |
| Cameron | 6% | n/a |
| Lomalta | 4% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 11.2% by land area here, and 49% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 45% of the mapped land.
Clay shrinks as it dries: 83.8% of Cameron County is in drought on the latest map, and 45% of Los Fresnos' mapped land has shrink-swell clay.
USDA rates 52% of the land very limited for septic absorption fields.
Drought in Cameron County
83.8% of Cameron County is in drought (D1 or worse) on the October 13, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Los Fresnos. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78566 | 100% | 22 | $596,200 |
Homes in Los Fresnos
| Housing units | 2,600 |
| Median year built | 1999 |
| Built before 1980 | 27% |
| Built 2000 or later | 49% |
| Owner-occupied | 62% |
| Median value, owner-occupied | $152,200 |
| Single-family detached | 77% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Indian Lake | 1 mi | 15% | 0% |
| Rancho Viejo | 5 mi | 26% | 5% |
| Brownsville | 6 mi | 41% | 31% |
| Bayview | 7 mi | 27% | 3% |
| San Benito | 10 mi | 63% | 4% |
| Port Isabel | 11 mi | 7% | 54% |
| Laguna Vista | 12 mi | 34% | 64% |
| Rio Hondo | 12 mi | 39% | 21% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status