Soil survey area

Minnehaha County, South Dakota

Survey Area SD099• South Dakota
The short version

The most common soil here is Nora, on about 12% of the land: a silty clay loam, smooth and slightly sticky. Moody and Egan come next.

About 75% of the land drains well, and 21% stays wet for long stretches; groundwater comes within two feet of the surface under 17% of it.

USDA rates 79% of the land very limited for a standard septic drain field, and 28% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 16% 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 Minnehaha County, South Dakota, each drawn five feet deep from its official USDA description, in its recorded colors.

Nora
12% of the area
Silty clay loam topsoil · well drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Moody
10% of the area
Silty clay loam topsoil · well drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Egan
8% of the area
Silty clay loam topsoil · well drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Trent
8% of the area
Silty clay loam topsoil · well drained
Smooth and slightly sticky. Holds a lot of water.
Mollisols
Ethan
6% of the area
Loam topsoil · well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Mollisols
Crofton
5% of the area
Silt loam topsoil · well drained
Smooth, like flour. Fertile and holds water well.
Entisols

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 Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). 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 Minnehaha County, South Dakota. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Nora-Crofton complex, 6 to 9 percent slopes 70K Well drainedCNot limitedSomewhat limited
Moody-Nora complex, 2 to 6 percent slopes 51K Well drainedCSomewhat limitedVery limited
Egan-Ethan-Trent complex, 1 to 6 percent slopes 50K Well drainedCSomewhat limitedVery limited
Ethan-Egan complex, 5 to 9 percent slopes 28K Well drainedCSomewhat limitedVery limited
Egan-Wentworth-Trent complex, 2 to 6 percent slopes 21K Well drainedCSomewhat limitedVery limited
Whitewood silty clay loam, 0 to 2 percent slopes, occasionally flooded 17K Somewhat poorly drainedCVery limitedVery limited
Moody silty clay loam, cool, 2 to 6 percent slopes 16K Well drainedCSomewhat limitedVery limited
Clamo silty clay, 0 to 1 percent slopes 13K Poorly drainedC/DVery limitedVery limited
Moody-Trent complex, 0 to 2 percent slopes 13K Well drainedCSomewhat limitedVery limited
Obert silty clay loam, 0 to 1 percent slopes 11K Very poorly drainedC/DVery limitedVery limited
Crofton-Nora complex, 9 to 15 percent slopes 10K Well drainedBSomewhat limitedSomewhat limited
Lamo silty clay loam, channeled 10K Somewhat poorly drainedCVery limitedVery limited
Chaska loam, channeled, 0 to 3 percent slopes, frequently flooded 10K Somewhat poorly drainedB/DVery limitedVery limited
Worthing-Davison complex, 0 to 2 percent slopes 9K Very poorly drainedC/DVery limitedVery limited
Wakonda-Chancellor complex, 0 to 2 percent slopes 9K Somewhat poorly drainedC/DVery limitedVery limited
Thurman-Flandreau complex, 6 to 9 percent slopes 8K Well drainedANot limitedVery limited
Chancellor-Tetonka complex, 0 to 2 percent slopes 7K Somewhat poorly drainedC/DVery limitedVery limited
Moody-Nora silty clay loams, 6 to 9 percent slopes 7K Well drainedBSomewhat limitedSomewhat limited
Trent silty clay loam, 0 to 3 percent slopes 7K Well drainedCSomewhat limitedVery limited
Dempster silt loam, 0 to 2 percent slopes 7K Well drainedBNot 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.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 28% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.

Septic Systems

About 79% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.

Look Up a Specific Address

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