Soil series profile
Bolar soil series
Bolar is a well drained soil with a clay loam surface, mapped on 529,013 acres in 31 counties across 2 states. Hydrologic group C.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- C 80% of mapped acres
- Typical topsoil pH
- 8.0 moderately alkaline · range 8.0–8.2
- Mapped area
- 529k acres in 31 counties, 2 states
Typical Bolar profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–18 in (A) | Clay loam | 8.0 | 30% | 34% | 2.5% |
| 18–30 in (Bk1) | Loam | 8.0 | 25% | 38% | 1.25% |
| 30–36 in (Bk2) | Loam | 8.1 | 25% | 38% | 0.5% |
| 36–80 in (R) | Bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Bolar soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Bolar soils is moderately alkaline: pH 8.0 (most land between 8.0 and 8.2). Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).
Loamy topsoil (loam, silt loam and similar) covers 77% of mapped Bolar acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is clay loam (56% of mapped Bolar acres).
100% of mapped Bolar acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 80% 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.
For a septic system
For conventional septic absorption fields, NRCS rates 77% of the acres in mapped Bolar soils very limited, 0% somewhat limited and 0% not limited (23% 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 Bolar soil is found
Mapped acres
Bolar is mapped in Texas and Oklahoma.
| County | Acres | Share of county land |
|---|---|---|
| Mills County, TX | 65,113 | 13.6% |
| Johnson County, TX | 45,456 | 9.8% |
| Coryell County, TX | 41,687 | 6.2% |
| Burnet County, TX | 40,124 | 6.3% |
| Comanche County, TX | 39,863 | 6.6% |
| Parker County, TX | 38,062 | 6.6% |
| Cooke County, TX | 27,934 | 5.0% |
| Tarrant County, TX | 24,517 | 4.4% |
| Hood County, TX | 24,363 | 9.0% |
| Bosque County, TX | 20,271 | 3.2% |
| McLennan County, TX | 18,480 | 2.8% |
| Erath County, TX | 17,744 | 2.6% |
| Brown County, TX | 16,395 | 2.7% |
| Blanco County, TX | 14,602 | 3.2% |
| Comal County, TX | 12,777 | 3.0% |
| Hamilton County, TX | 11,557 | 2.2% |
| Hays County, TX | 9,009 | 2.5% |
| Wise County, TX | 8,893 | 1.5% |
| Montague County, TX | 7,804 | 1.3% |
| Hill County, TX | 7,751 | 1.3% |
| Eastland County, TX | 6,841 | 1.2% |
| Denton County, TX | 6,726 | 1.2% |
| Bell County, TX | 5,210 | 0.8% |
| Somervell County, TX | 4,997 | 4.2% |
| Lampasas County, TX | 3,962 | 0.9% |
| Grayson County, TX | 3,725 | 0.6% |
| Williamson County, TX | 1,803 | 0.3% |
| Kendall County, TX | 1,712 | 0.4% |
| Marshall County, OK | 862 | 0.4% |
| Love County, OK | 500 | 0.2% |
| Shackelford County, TX | 273 | 0.0% |
Septic absorption fields
NRCS rating, share of Bolar acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 76.8% |
| Not rated | 23.2% |
Drainage, water table and flooding
Share of Bolar acres
- Depth to seasonal high water table
- None reported within about 6.5 feet (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 2–5% (median 4%).
- Topsoil organic matter
- Median 2.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| 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 | 79.5% |
| D: very slow infiltration (clayey, shallow or wet) | 0.0% |
| 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 | 20.5% |
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 Bolar (component kind "Series") in SSURGO: 529,013 acres.
- Method
- Shares are by mapped acres of Bolar components. The profile comes from the single largest Bolar component. Full methodology.