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Rio Grande City, Texas
Inside Rio Grande City's city limits, shrink-swell clay limits houses without basements on 7% of mapped land, the 4th-highest of 4 cities in Starr County. A shallow water table limits basements on 1%, the 3rd-highest of 4 cities in Starr County.
That clay share is below Starr County's 14%. FEMA's flood data list 25 flood losses since 2016 in ZIP code 78582 overlapping the city. Of its 5,168 homes, 24% were built before 1980; the median dates from 1991.
Data as of October 13, 2026 · sources · in Starr 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 Rio Grande City
Foundation repair in Rio Grande City: shrink-swell clay limits slab homes on 7% of Rio Grande City's mapped land.
About 3,600 of Rio Grande City's 5,168 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 Rio Grande City city limits
| Expansive clay (limits slab homes) | 7.1% |
| High water table (limits basements) | 0.8% |
| Septic fields very limited | 47.1% |
| Clay swell (LEP, by area) | 2.9% |
| High-swell land (LEP 6%+) | 7.1% |
| Mapped soil | 7,256 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| McAllen | 23% | n/a |
| Lagloria | 17% | n/a |
| Rio Grande | 11% | n/a |
| Zapata | 7% | n/a |
| Copita | 7% | n/a |
| Camargo | 6% | n/a |
What the numbers mean here
With shrink-swell clay on 7% and a shallow water table on 1% of the land, the soil survey points to neither problem across most of Rio Grande City; conditions still vary lot by lot.
Drought in Starr County
100% of Starr 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 Rio Grande City. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78582 | 100% | 25 | $1.1 million |
Homes in Rio Grande City
| Housing units | 5,168 |
| Median year built | 1991 |
| Built before 1980 | 24% |
| Built 2000 or later | 37% |
| Owner-occupied | 69% |
| Median value, owner-occupied | $113,200 |
| Single-family detached | 70% |
Nearby cities
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