County soil summary

Soil types in Tarrant County, Texas

The most widespread soils are Sanger, Aledo and Crosstell; the most common drainage class is well drained (61% of the land), and typical topsoil pH is 7.8.

Mapped soil survey data 552,000 acres of mapped land · 79 named soil series

Well or moderately well drained
89%
of land · state 88%
Typical topsoil pH
7.8
slightly alkaline · state 7.5
Septic fields very limited
70%
of land · state 71%
Subject to flooding
8%
of land, any frequency · state 10%

Most common soils in Tarrant County

Share of mapped land

A county is a patchwork of many soils. These 8 cover 53% of the mapped land; 79 named soil series are mapped here in all.

Most common soils in Tarrant County by share of mapped land
Soil Share of land Drainage Topsoil pH
Urban landLand type, not a soil series 12.2% — —
Sanger 9.9% Well drained 7.9
Aledo 7.4% Well drained 7.8
Crosstell 5.7% Moderately well drained 6.3
Gasil 5.2% Well drained 7.0
Bolar 4.4% Well drained 8.0
Purves 3.9% Well drained 8.0
Slidell 3.8% Moderately well drained 8.0

Drainage and pH for a series are its typical values across all its mapped acres nationwide. A dash means the row is not a soil series.

What this means

What the soils in Tarrant County mean for gardens, lawns and septic systems

For your garden

Typical topsoil in Tarrant County is slightly alkaline: pH 7.8 (most land between 6.3 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 42% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is clay (24% of the land).

89% of the land is moderately well to excessively drained, which suits most garden plants.

For your lawn and yard

On 75% of the land, 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 70% of the land in Tarrant County very limited, 12% somewhat limited and 0% not limited (18% not rated, such as urban land, pits or water).

That is close to the state as a whole (71% very limited).

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.

Flooding is mapped on 8% of the land (3% occasional, 5% frequent).

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Drainage

How long the soil stays wet

The most common drainage class is well drained (61%). 89% of the land is moderately well drained or better, compared with 88% across Texas.

Excessively drained 0%
Somewhat excessively drained <1%
Well drained 61%
Moderately well drained 27%
Somewhat poorly drained 0%
Poorly drained 0%
Very poorly drained 0%
Not rated 11%
Natural drainage class, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
Show as a table
Natural drainage class, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
Excessively drained0.0%1.0%
Somewhat excessively drained0.6%1.4%
Well drained61.0%69.9%
Moderately well drained27.0%15.8%
Somewhat poorly drained0.0%3.7%
Poorly drained0.0%2.2%
Very poorly drained0.0%0.5%
Not rated11.4%5.6%

Septic absorption fields

NRCS rating for conventional drain fields

The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.

Not limited 0%
Somewhat limited 12%
Very limited 70%
Not rated 18%
Septic tank absorption field rating, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
Not limited0.0%1.4%
Somewhat limited11.7%16.7%
Very limited70.3%70.9%
Not rated18.0%11.0%

Rain, runoff and water table

Hydrologic soil group, flooding, seasonal water table

Hydrologic soil group

How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.

A: fast infiltration (mostly sandy or gravelly) 3%
B: moderate infiltration 14%
C: slow infiltration 18%
D: very slow infiltration (clayey, shallow or wet) 56%
A/D: D as is, A if drained 0%
B/D: D as is, B if drained 0%
C/D: D as is, C if drained 0%
Not rated 9%
Hydrologic soil group, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
A: fast infiltration (mostly sandy or gravelly)2.6%7.2%
B: moderate infiltration13.7%20.0%
C: slow infiltration18.4%22.9%
D: very slow infiltration (clayey, shallow or wet)56.1%38.3%
A/D: D as is, A if drained0.0%0.1%
B/D: D as is, B if drained0.0%0.8%
C/D: D as is, C if drained0.0%1.8%
Not rated9.2%8.8%

Flooding

No flooding 89%
Rare or very rare 0%
Occasional 3%
Frequent or very frequent 5%
Not reported 3%
Most frequent flooding class in any month, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
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Most frequent flooding class in any month, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
No flooding88.9%86.1%
Rare or very rare0.0%2.1%
Occasional3.4%3.4%
Frequent or very frequent5.0%4.6%
Not reported2.7%3.7%

Seasonal high water table

Within 18 inches at some time of year <1%
18 inches to 3.3 feet 4%
Deeper than 3.3 feet or none reported 96%
Not reported 0%
Shallowest depth to a saturated zone in any month, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
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Shallowest depth to a saturated zone in any month, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
Within 18 inches at some time of year0.1%5.7%
18 inches to 3.3 feet3.6%3.6%
Deeper than 3.3 feet or none reported96.3%89.0%
Not reported0.0%1.6%

Topsoil pH and texture

First mineral layer of each soil

Typical topsoil pH is 7.8 (slightly alkaline); 80% of rated land falls between 6.3 and 8.2. Median topsoil organic matter is 2%.

Strongly acidic (below 5.5) 0%
Moderately to slightly acidic (5.5–6.4) 14%
Near neutral (6.5–7.3) 18%
Alkaline (7.4 and up) 43%
Not reported 24%
Topsoil pH band, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil pH band, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
Strongly acidic (below 5.5)0.0%5.2%
Moderately to slightly acidic (5.5–6.4)14.2%9.8%
Near neutral (6.5–7.3)18.1%24.9%
Alkaline (7.4 and up)43.2%46.8%
Not reported24.4%13.3%

Texture

Sandy 6%
Loamy (loam, silt loam and similar) 42%
Clayey (40%+ clay) 28%
Organic (muck or peat) 0%
Not reported (rock, urban land, etc.) 24%
Topsoil texture group, share of mapped land in Tarrant County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil texture group, share of mapped land in Tarrant County.
CategoryTarrant CountyTexas
Sandy5.7%14.6%
Loamy (loam, silt loam and similar)42.3%56.0%
Clayey (40%+ clay)27.6%15.9%
Organic (muck or peat)0.0%0.1%
Not reported (rock, urban land, etc.)24.4%13.4%

Most common surface textures: clay 24% · fine sandy loam 20% · clay loam 13% · gravelly clay loam 8% · silty clay 4%.

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
Tarrant County, Texas (FIPS 48439): 551,660 acres of mapped land, 23,457 acres of open water excluded. State comparisons pool all mapped land in Texas.
Method
Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.

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