Soil survey area

Webster County, Iowa

Survey Area IA187• Iowa
The short version

The most common soil here is Webster, on about 18% of the land: a silty clay loam, smooth and slightly sticky. Nicollet and Clarion come next.

About 10% of the land drains well, and 75% stays wet for long stretches; groundwater comes within two feet of the surface under 75% of it.

USDA rates 94% of the land very limited for a standard septic drain field, and 80% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 3% of the land floods occasionally or more, and bedrock lies within 40 inches under 1% of it.

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 Webster County, Iowa, each drawn five feet deep from its official USDA description, in its recorded colors.

Webster
18% of the area
Silty clay loam topsoil · poorly drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Nicollet
13% of the area
Clay loam topsoil · somewhat poorly drained
Firm and a little sticky. Holds water and nutrients well.
Mollisols
Clarion
12% of the area
Loam topsoil · well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Mollisols
Kossuth
9% of the area
Silty clay loam topsoil · poorly drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Canisteo
9% of the area
Clay loam topsoil · poorly drained
Firm and a little sticky. Holds water and nutrients well.
Mollisols
Okoboji
8% of the area
Silty clay loam topsoil · very poorly drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols

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 C/D (varies with drainage). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Webster County, Iowa. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Webster clay loam, 0 to 2 percent slopes 85K Poorly drainedC/DVery limitedVery limited
Nicollet clay loam, 1 to 3 percent slopes 55K Somewhat poorly drainedC/DVery limitedVery limited
Kossuth silty clay loam, 0 to 2 percent slopes 50K Poorly drainedC/DVery limitedVery limited
Canisteo clay loam, 0 to 2 percent slopes 50K Poorly drainedC/DVery limitedVery limited
Clarion loam, 2 to 6 percent slopes 45K Moderately well drainedCSomewhat limitedVery limited
Okoboji silty clay loam, 0 to 1 percent slopes 21K Very poorly drainedC/DVery limitedVery limited
Lester-Belview complex, 22 to 40 percent slopes 16K Well drainedCVery limitedVery limited
Nicollet-Guckeen complex, 1 to 3 percent slopes 11K Somewhat poorly drainedDVery limitedVery limited
Brownton silty clay loam, 0 to 2 percent slopes 11K Poorly drainedC/DVery limitedVery limited
Harps clay loam, 0 to 2 percent slopes 10K Poorly drainedC/DVery limitedVery limited
Clarion loam, 6 to 10 percent slopes, moderately eroded 8K Well drainedBSomewhat limitedSomewhat limited
Guckeen clay loam, 1 to 3 percent slopes 8K Somewhat poorly drainedC/DVery limitedVery limited
Coland clay loam, 0 to 2 percent slopes, occasionally flooded 5K Poorly drainedC/DVery limitedVery limited
Fluvaquents, loamy, 0 to 2 percent slopes, frequently flooded 4K Very poorly drainedA/DVery limitedVery limited
Pits, gypsum quarries 4K Not ratedNot rated
Wacousta silty clay loam, depressional, 0 to 1 percent slopes 4K Very poorly drainedC/DVery limitedVery limited
Corvuso-Brownton complex, 0 to 2 percent slopes 4K Poorly drainedDVery limitedVery limited
Water 3K Not ratedNot rated
Angus loam, 2 to 6 percent slopes 3K Well drainedCSomewhat limitedVery limited
Clarion clay loam, 2 to 5 percent slopes 3K Moderately well drainedCSomewhat limitedSomewhat 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.

Mollisols
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Alfisols
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 80% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 94% 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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