Dallas County, Iowa

Survey Area IA049• Iowa

The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Dallas 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
Clarion loam, Bemis moraine, 2 to 6 percent slopes	76K	Well drained	B	Somewhat limited	Somewhat limited
Canisteo clay loam, Bemis moraine, 0 to 2 percent slopes	49K	Poorly drained	C/D	Very limited	Very limited
Nicollet loam, 1 to 3 percent slopes	40K	Somewhat poorly drained	B/D	Very limited	Very limited
Webster clay loam, Bemis moraine, 0 to 2 percent slopes	28K	Poorly drained	C/D	Very limited	Very limited
Clarion loam, Bemis moraine, 6 to 10 percent slopes, moderately eroded	23K	Well drained	B	Somewhat limited	Somewhat limited
Clarion loam, 2 to 5 percent long slopes	14K	Well drained	B	Somewhat limited	Somewhat limited
Sharpsburg silty clay loam, 5 to 9 percent slopes, eroded	9K	Moderately well drained	C	Somewhat limited	Very limited
Sharpsburg silty clay loam, 2 to 5 percent slopes	8K	Moderately well drained	C	Somewhat limited	Very limited
Coland clay loam, 0 to 2 percent slopes, occasionally flooded	8K	Poorly drained	C/D	Very limited	Very limited
Hayden-Storden loams, 25 to 50 percent slopes	6K	Well drained	B	Very limited	Very limited
Dockery-Quiver silt loams, 0 to 2 percent slopes, occasionally flooded	5K	Somewhat poorly drained	B/D	Very limited	Very limited
Coland-Terril complex, 2 to 5 percent slopes	5K	Poorly drained	C/D	Very limited	Very limited
Hanlon-Spillville complex, channeled, 0 to 2 percent slopes	5K	Moderately well drained	A	Very limited	Very limited
Ladoga silty clay loam, dissected till plain, 5 to 9 percent slopes, eroded	5K	Moderately well drained	C	Very limited	Very limited
Water	4K			Not rated	Not rated
Lindley silt loam, 18 to 40 percent slopes	4K	Well drained	C	Very limited	Very limited
Gara-Armstrong complex, 14 to 18 percent slopes	4K	Somewhat poorly drained	D	Very limited	Very limited
Clarion loam, 9 to 14 percent slopes, moderately eroded	3K	Well drained	B	Somewhat limited	Somewhat limited
Lester loam, Bemis moraine, 2 to 6 percent slopes	3K	Well drained	C	Somewhat limited	Very limited
Colo, occasionally flooded-Ely silty clay loams, dissected till plain, 2 to 5 percent slopes	3K	Poorly drained	C/D	Very 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.

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 53% 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 60% 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

Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.