Soil survey area

Humboldt County, Iowa

Survey Area IA091• Iowa
The short version

The most common soil here is Canisteo, on about 24% of the land: a clay loam, firm and a little sticky. Clarion and Webster come next.

About 10% of the land drains well, and 69% stays wet for long stretches; groundwater comes within two feet of the surface under 69% of it.

USDA rates 95% of the land very limited for a standard septic drain field, and 70% 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.

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

Canisteo
24% of the area
Clay loam topsoil · poorly drained
Firm and a little sticky. Holds water and nutrients well.
Mollisols
Clarion
17% of the area
Loam topsoil · well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Mollisols
Webster
13% of the area
Silty clay loam topsoil · poorly drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Nicollet
11% of the area
Clay loam topsoil · somewhat poorly drained
Firm and a little sticky. Holds water and nutrients well.
Mollisols
Okoboji
9% of the area
Silty clay loam topsoil · very poorly drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Harps
5% of the area
Clay loam topsoil · poorly drained
Firm and a little sticky. Holds water and nutrients well.
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 Humboldt County, Iowa. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Canisteo clay loam, 0 to 2 percent slopes 86K Poorly drainedC/DVery limitedVery limited
Clarion loam, 2 to 6 percent slopes 47K Moderately well drainedCSomewhat limitedVery limited
Webster clay loam, 0 to 2 percent slopes 33K Poorly drainedC/DVery limitedVery limited
Nicollet clay loam, 1 to 3 percent slopes 30K Somewhat poorly drainedC/DVery limitedVery limited
Okoboji silty clay loam, 0 to 1 percent slopes 8K Very poorly drainedC/DVery limitedVery limited
Garmore clay loam, 0 to 2 percent slopes 8K Moderately well drainedCSomewhat limitedVery limited
Harps clay loam, 0 to 2 percent slopes 7K Poorly drainedC/DVery limitedVery limited
Wacousta silty clay loam, depressional, 0 to 1 percent slopes 6K Very poorly drainedC/DVery limitedVery limited
Clarion loam, 6 to 10 percent slopes, moderately eroded 5K Well drainedBSomewhat limitedSomewhat limited
Spillville-Coland complex, channeled, 0 to 2 percent slopes, frequently flooded 5K Somewhat poorly drainedB/DVery limitedVery limited
Harps-Okoboji complex, 0 to 2 percent slopes 5K Poorly drainedC/DVery limitedVery limited
Lester loam, 2 to 6 percent slopes 4K Well drainedCSomewhat limitedVery limited
Clarion-Storden complex, 6 to 10 percent slopes, moderately eroded 3K Well drainedBSomewhat limitedSomewhat limited
Calcousta silty clay loam, 0 to 1 percent slopes 2K Very poorly drainedC/DVery limitedVery limited
Ridgeport sandy loam, 0 to 2 percent slopes 2K Somewhat excessively drainedANot limitedVery limited
Biscay clay loam, 0 to 2 percent slopes 1K Poorly drainedC/DVery limitedVery limited
Okoboji mucky silty clay loam, depressional, 0 to 1 percent slopes 1K Very poorly drainedC/DVery limitedVery limited
Wadena loam, 0 to 2 percent slopes 1K Well drainedBNot limitedVery limited
Wacousta mucky silty clay loam, depressional, 0 to 1 percent slopes 1K Very poorly drainedC/DVery limitedVery limited
Rolfe silt loam, 0 to 1 percent slopes 1K Very 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.

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.
Inceptisols
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.

What This Means

Building & Foundations

About 70% 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 95% 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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