San Patricio and Aransas Counties, Texas
The most common soil here is Victoria, on about 23% of the land: a clay, sticky when wet and rock-hard when dry. Calallen and Raymondville come next.
About 36% of the land drains well, and 20% stays wet for long stretches; groundwater comes within two feet of the surface under 23% of it.
USDA rates 67% of the land very limited for a standard septic drain field, and 63% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 18% of the land floods occasionally or more.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in San Patricio and Aransas Counties, Texas, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Vertisols — clay-rich soils that shrink and swell dramatically with moisture changes. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in San Patricio and Aransas Counties, Texas. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Victoria clay 0 to 1 percent slopes | 158K | Well drained | C | Very limited | Very limited |
| Water | 131K | D | Not rated | Not rated | |
| Calallen sandy clay loam, 0 to 1 percent slopes | 64K | Well drained | B | Somewhat limited | Somewhat limited |
| Galveston-Mustang complex, 0 to 3 percent slopes, occasionally flooded, frequently ponded | 62K | Moderately well drained | A | Very limited | Very limited |
| Raymondville clay loam, 0 to 1 percent slopes | 54K | Moderately well drained | C | Very limited | Very limited |
| Narta loam, 0 to 1 percent slopes, rarely flooded | 26K | Poorly drained | D | Very limited | Very limited |
| Imogene-Calallen complex, 0 to 1 percent slopes | 25K | Moderately well drained | B | Somewhat limited | Not limited |
| Aransas clay, 0 to 1 percent slopes, slightly saline, moderately sodic, frequently flooded | 23K | Poorly drained | C/D | Very limited | Very limited |
| Mustang fine sand, 0 to 1 percent slopes, occasionally flooded, frequently ponded | 18K | Poorly drained | C/D | Very limited | Very limited |
| Barrada-Tatton association, 0 to 1 percent slopes, occasionally ponded | 18K | Very poorly drained | D | Very limited | Very limited |
| Banquete clay, 0 to 1 percent slopes | 15K | Moderately well drained | C | Very limited | Very limited |
| Orelia fine sandy loam, 0 to 1 percent slopes | 14K | Well drained | C | Somewhat limited | Very limited |
| Victoria clay, 0 to 1 percent slopes, low | 14K | Somewhat poorly drained | D | Very limited | Very limited |
| Dianola soils | 11K | Poorly drained | A | Very limited | Very limited |
| Victine clay loam, 0 to 1 percent slopes | 11K | Somewhat poorly drained | D | Very limited | Very limited |
| Delfina loamy fine sand, 0 to 3 percent slopes | 9K | Moderately well drained | C | Somewhat limited | Very limited |
| Tatton complex, 0 to 1 percent slopes, occasionally ponded | 7K | Very poorly drained | A/D | Very limited | Very limited |
| Imogene-Calallen complex, 1 to 3 percent slopes | 7K | Moderately well drained | B | Somewhat limited | Not limited |
| Beaches | 6K | Very poorly drained | A | Very limited | Very limited |
| Dietrich loamy fine sand, 0 to 1 percent slopes, very rarely flooded | 6K | Poorly drained | C/D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 63% of soils are rated "very limited" for dwellings with basements. Specific challenges include poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 67% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.