Sac County, Iowa

Survey Area IA161• Iowa

The dominant drainage class is Well 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 Sac County, Iowa. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map Unit	Acres	Drainage	Hydro Group	Dwellings	Septic
Galva silty clay loam, 2 to 5 percent slopes	50K	Well drained	C	Somewhat limited	Very limited
Primghar silty clay loam, 0 to 2 percent slopes	31K	Somewhat poorly drained	C/D	Very limited	Very limited
Clarion loam, 2 to 6 percent slopes	30K	Moderately well drained	C	Somewhat limited	Very limited
Nicollet clay loam, 1 to 3 percent slopes	21K	Somewhat poorly drained	C/D	Very limited	Very limited
Canisteo clay loam, 0 to 2 percent slopes	21K	Poorly drained	C/D	Very limited	Very limited
Webster clay loam, 0 to 2 percent slopes	14K	Poorly drained	C/D	Very limited	Very limited
Clarion loam, Bemis moraine, 2 to 6 percent slopes	13K	Well drained	B	Somewhat limited	Somewhat limited
Marshall silty clay loam, 5 to 9 percent slopes, eroded	13K	Well drained	C	Somewhat limited	Very limited
Colo silty clay loam, deep loess, 0 to 2 percent slopes, occasionally flooded	12K	Poorly drained	C/D	Very limited	Very limited
Afton silty clay loam, 0 to 2 percent slopes, occasionally flooded	10K	Poorly drained	C/D	Very limited	Very limited
Nicollet loam, 1 to 3 percent slopes	8K	Somewhat poorly drained	B/D	Very limited	Very limited
Clarion loam, 6 to 10 percent slopes, moderately eroded	7K	Well drained	B	Somewhat limited	Somewhat limited
Webster clay loam, Bemis moraine, 0 to 2 percent slopes	6K	Poorly drained	C/D	Very limited	Very limited
Marcus silty clay loam, 0 to 2 percent slopes	6K	Poorly drained	C/D	Very limited	Very limited
Kennebec-Ackmore complex, 2 to 5 percent slopes, occasionally flooded	5K	Moderately well drained	C	Very limited	Very limited
Okoboji silty clay loam, 0 to 1 percent slopes	5K	Very poorly drained	C/D	Very limited	Very limited
Canisteo clay loam, Bemis moraine, 0 to 2 percent slopes	5K	Poorly drained	C/D	Very limited	Very limited
Sac silty clay loam, 5 to 9 percent slopes, eroded	4K	Moderately well drained	C	Somewhat limited	Very limited
Sac silty clay loam, loam substratum, 2 to 5 percent slopes	4K	Moderately well drained	C	Somewhat limited	Very limited
Galva silty clay loam, 5 to 9 percent slopes, eroded	4K	Well drained	C	Somewhat limited	Very 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.

Inceptisols

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

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 53% 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. 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.