Soil survey area

West Baton Rouge Parish, Lousiana

Survey Area LA121• Louisiana
The short version

The most common soil here is Sharkey, on about 40% of the land: a clay, sticky when wet and rock-hard when dry. Commerce and Robinsonville come next.

About 8% of the land drains well, and 84% stays wet for long stretches; groundwater comes within two feet of the surface under 46% of it.

USDA rates 92% of the land very limited for a standard septic drain field, and 57% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 9% 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 ground underfoot

The soils you're most likely standing on

The biggest named soils in West Baton Rouge Parish, Lousiana, each drawn five feet deep from its official USDA description, in its recorded colors.

Sharkey
40% of the area
Clay topsoil · poorly drained
Sticky when wet and rock-hard when dry. Drains slowly.
Vertisols
Commerce
32% of the area
Silt loam topsoil · somewhat poorly drained
Smooth, like flour. Fertile and holds water well.
Inceptisols
Robinsonville
5% of the area
Very fine sandy loam topsoil · well drained
Gritty and crumbly. Drains fast and warms early in spring.
Entisols
Tunica
4% of the area
Clay topsoil · poorly drained
Sticky when wet and rock-hard when dry. Drains slowly.
Inceptisols
Convent
2% of the area
Silt loam topsoil · somewhat poorly drained
Smooth, like flour. Fertile and holds water well.
Inceptisols
Bruin
2% of the area
Silt loam topsoil · moderately well drained
Smooth, like flour. Fertile and holds water well.
Inceptisols

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 Poorly drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Inceptisols — young soils with minimal horizon development but more than Entisols. 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 West Baton Rouge Parish, Lousiana. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Sharkey clay, 0 to 1 percent slopes, rarely flooded, deltaic plain 54K Poorly drainedDVery limitedVery limited
Commerce silty clay loam 24K Somewhat poorly drainedCSomewhat limitedVery limited
Commerce silt loam, 0 to 1 percent slopes 18K Somewhat poorly drainedCSomewhat limitedVery limited
Robinsonville and Commerce soils, occasionally flooded 10K Well drainedAVery limitedVery limited
Water 9K Not ratedNot rated
Convent silt loam, 0 to 1 percent slopes 4K Somewhat poorly drainedCSomewhat limitedVery limited
Tunica clay 3K Poorly drainedDVery limitedVery limited
Vacherie silt loam, 0 to 1 percent slopes 3K Somewhat poorly drainedCVery limitedVery limited
Sharkey silty clay loam 2K Poorly drainedDVery limitedVery limited
Bruin very fine sandy loam 1K Moderately well drainedBNot limitedSomewhat limited
Dowling clay, frequently flooded 555 Very poorly drainedDVery limitedVery limited
Commerce silty clay loam, occasionally flooded 433 Somewhat poorly drainedCVery limitedVery limited
Sharkey clay, 0 to 1 percent slopes, frequently flooded, deltaic plain 137 Poorly drainedDVery limitedVery limited
Sharkey clay, 0 to 1 percent slopes, occasionally flooded 86 Poorly drainedDVery limitedVery limited
Commerce silty clay loam, gently undulating 75 Somewhat poorly drainedCSomewhat limitedVery limited
Sharkey-Tunica complex, gently undulating 47 Poorly drainedDVery limitedVery limited
Mhoon silty clay loam 28 Poorly drainedC/DVery limitedVery 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.

Inceptisols
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Vertisols
High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.
Alfisols
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.

What This Means

Building & Foundations

About 57% 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 92% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.

Look Up a Specific Address

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