Soil survey area

Catahoula Parish, Louisiana

Survey Area LA025• Louisiana
The short version

The most common soil here is Sharkey, on about 17% of the land: a clay, sticky when wet and rock-hard when dry. Alligator and Tensas come next.

About 19% of the land drains well, and 72% stays wet for long stretches; groundwater comes within two feet of the surface under 73% of it.

USDA rates 90% of the land very limited for a standard septic drain field, and 89% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 30% 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 Catahoula Parish, Louisiana, each drawn five feet deep from its official USDA description, in its recorded colors.

Sharkey
17% of the area
Clay topsoil · poorly drained
Sticky when wet and rock-hard when dry. Drains slowly.
Vertisols
Alligator
12% of the area
Clay topsoil · poorly drained
Sticky when wet and rock-hard when dry. Drains slowly.
Vertisols
Tensas
8% of the area
Clay topsoil · somewhat poorly drained
Sticky when wet and rock-hard when dry. Drains slowly.
Alfisols
Dundee
7% of the area
Loam topsoil · somewhat poorly drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Guyton
4% of the area
Silt loam topsoil · poorly drained
Smooth, like flour. Fertile and holds water well.
Alfisols
Smithdale
4% of the area
Fine sandy loam topsoil · well drained
Gritty and crumbly. Drains fast and warms early in spring.
Ultisols

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 Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Catahoula Parish, Louisiana. 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, south 46K Poorly drainedDVery limitedVery limited
Alligator clay, 0 to 1 percent slopes, occasionally flooded 31K Poorly drainedDVery limitedVery limited
Sharkey clay, 0 to 1 percent slopes, occasionally flooded 28K Poorly drainedDVery limitedVery limited
Water 28K Not ratedNot rated
Tensas-Alligator complex, undulating 25K Somewhat poorly drainedDVery limitedVery limited
Alligator clay, frequently flooded 20K Poorly drainedDVery limitedVery limited
Smithdale-Oula-Providence association, 5 to 40 percent slopes 17K Well drainedBVery limitedVery limited
Guyton silt loam, 0 to 1 percent slopes, frequently flooded 16K Poorly drainedC/DVery limitedVery limited
Smithdale-Briley(lucy)-Providence association, 5 to 25 percent slopes 14K Well drainedBVery limitedVery limited
Oula-Providence association, 5 to 25 percent slopes 13K Well drainedDVery limitedVery limited
Tensas silty clay, 0 to 1 percent slopes, rarely flooded 12K Somewhat poorly drainedDVery limitedVery limited
Dundee silt loam, 0 to 1 percent slopes 12K Somewhat poorly drainedCVery limitedVery limited
Dundee silty clay loam, 0 to 1 percent slopes 12K Somewhat poorly drainedCVery limitedVery limited
Tensas-Alligator complex, undulating, occasionally flooded 11K Somewhat poorly drainedDVery limitedVery limited
Dundee-Alligator complex, gently undulating 11K Somewhat poorly drainedCSomewhat limitedVery limited
Hebert silt loam, 0 to 1 percent slopes 11K Somewhat poorly drainedCVery limitedVery limited
Sweatman-Smithdale association, 5 to 40 percent slopes 10K Well drainedCVery limitedVery limited
Perry clay, 0 to 1 percent slopes, occasionally flooded, Arkansas River 10K Poorly drainedDVery limitedVery limited
Oula-Providence-Smithdale association, 5 to 40 percent slopes 9K Well drainedVery limitedVery limited
Calloway silt loam 8K Somewhat 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.

Alfisols
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Vertisols
High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.
Ultisols
Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 89% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 90% 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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