Washington County, Texas
The most common soil here is Frelsburg, on about 12% of the land: a clay, sticky when wet and rock-hard when dry. Carbengle and Bleiblerville come next.
About 38% of the land drains well, and 3% stays wet for long stretches; groundwater comes within two feet of the surface under 6% of it.
USDA rates 93% of the land very limited for a standard septic drain field, and 68% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 14% of the land floods occasionally or more, and bedrock lies within 40 inches under 22% of it.
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 Washington County, 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 Moderately well drained and the dominant hydrologic group is D (very slow infiltration, high 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 Washington County, 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 |
|---|---|---|---|---|---|
| Frelsburg clay, 3 to 5 percent slopes | 34K | Moderately well drained | D | Very limited | Very limited |
| Falba fine sandy loam, 1 to 5 percent slopes | 21K | Moderately well drained | D | Very limited | Very limited |
| Bosque clay loam, frequently flooded | 21K | Well drained | B | Very limited | Very limited |
| Trinity clay, 0 to 1 percent slopes, frequently flooded | 18K | Moderately well drained | D | Very limited | Very limited |
| Chazos loamy fine sand, 1 to 5 percent slopes | 18K | Moderately well drained | C | Somewhat limited | Very limited |
| Bleiblerville clay, 1 to 3 percent slopes | 17K | Moderately well drained | D | Very limited | Very limited |
| Frelsburg clay, 1 to 3 percent slopes | 17K | Moderately well drained | D | Very limited | Very limited |
| Crockett fine sandy loam, 1 to 5 percent slopes | 15K | Moderately well drained | D | Somewhat limited | Very limited |
| Brenham clay loam, 3 to 8 percent slopes | 13K | Well drained | B | Somewhat limited | Somewhat limited |
| Carbengle clay loam, 5 to 8 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Carbengle clay loam, 3 to 5 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Frelsburg clay, 5 to 8 percent slopes | 12K | Moderately well drained | D | Very limited | Very limited |
| Latium clay, 5 to 8 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Brazoria clay, 0 to 1 percent slopes, rarely flooded | 10K | Moderately well drained | D | Very limited | Very limited |
| Tabor fine sandy loam, 1 to 5 percent slopes | 10K | Moderately well drained | D | Very limited | Very limited |
| Tremona loamy fine sand, 1 to 5 percent slopes | 9K | Somewhat poorly drained | A | Somewhat limited | Very limited |
| Water | 9K | D | Not rated | Not rated | |
| Burlewash fine sandy loam, 1 to 5 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Wilson clay loam, 1 to 3 percent slopes | 6K | Moderately well drained | D | Very limited | Very limited |
| Silawa loamy fine sand, 1 to 5 percent slopes | 6K | Well drained | B | Not 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 68% 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 93% 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.