Soil series profile
Edna soil series
Edna is a somewhat poorly drained soil with a loam surface, mapped on 471,238 acres in 15 counties in TX. Hydrologic group D.
- Drainage class
- Somewhat poorly drained 100% of mapped acres
- Hydrologic group
- D 89% of mapped acres
- Typical topsoil pH
- 5.5 strongly acidic · range 5.5–5.5
- Mapped area
- 471k acres in 15 counties, 1 state
Typical Edna profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–9 in (A) | Loam | 5.5 | 21% | 38% | 3.03% |
| 9–38 in (Bt1) | Clay | 7.3 | 43% | 38% | 1.51% |
| 38–50 in (Bt2) | Clay | 6.8 | 41% | 23% | 1.01% |
| 50–80 in (Btk) | Sandy clay loam | 8.1 | 29% | 54% | 0.3% |

What this means
What Edna soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Edna soils is strongly acidic: pH 5.5. Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.
Loamy topsoil (loam, silt loam and similar) covers 87% of mapped Edna acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (81% of mapped Edna acres).
100% of mapped Edna acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.
For lawns and yards
On 89% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.
A seasonal high water table comes within 18 inches of the surface on 94% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 89% of the acres in mapped Edna soils very limited, 0% somewhat limited and 0% not limited (11% not rated, such as urban land, pits or water).
Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Edna soil is found
Mapped acres
Edna is mapped in Texas.
| County | Acres | Share of county land |
|---|---|---|
| Wharton County, TX | 114,359 | 16.4% |
| Fort Bend County, TX | 101,549 | 18.4% |
| Matagorda County, TX | 76,367 | 10.8% |
| Brazoria County, TX | 73,950 | 8.1% |
| Victoria County, TX | 35,887 | 6.4% |
| Jackson County, TX | 22,553 | 4.3% |
| Harris County, TX | 13,140 | 1.2% |
| Galveston County, TX | 10,470 | 3.4% |
| Calhoun County, TX | 7,416 | 2.2% |
| Austin County, TX | 4,629 | 1.1% |
| Colorado County, TX | 2,613 | 0.4% |
| Waller County, TX | 2,246 | 0.7% |
| DeWitt County, TX | 2,223 | 0.4% |
| Goliad County, TX | 1,991 | 0.4% |
| Lavaca County, TX | 1,846 | 0.3% |
Septic absorption fields
NRCS rating, share of Edna acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 89.2% |
| Not rated | 10.8% |
Drainage, water table and flooding
Share of Edna acres
- Depth to seasonal high water table
- About 4 inches (median where reported); within 18 inches on 94% of acres.
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 0–0% (median 0%).
- Topsoil organic matter
- Median 3%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 100.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 89.2% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.0% |
| Not rated | 10.8% |
Sources & data dates
- Source
- USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
- Data date
- SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
- Scope
- All map unit components named Edna (component kind "Series") in SSURGO: 471,238 acres.
- Method
- Shares are by mapped acres of Edna components. The profile comes from the single largest Edna component. Full methodology.