McHenry County, Illinois
The most common soil here is Kidder, on about 6% of the land: a silt loam, smooth, like flour. Pella and Kidami come next.
About 47% of the land drains well, and 39% stays wet for long stretches; groundwater comes within two feet of the surface under 38% of it.
USDA rates 95% of the land very limited for a standard septic drain field, and 43% 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 soils you're most likely standing on
The biggest named soils in McHenry County, Illinois, each drawn five feet deep from its official USDA description, in its recorded colors.
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 B (moderate infiltration). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 McHenry County, Illinois. 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 |
|---|---|---|---|---|---|
| Pella silty clay loam, cool, 0 to 2 percent slopes | 21K | Poorly drained | C/D | Very limited | Very limited |
| Ringwood silt loam, 2 to 4 percent slopes | 17K | Well drained | B | Not limited | Very limited |
| McHenry silt loam, 2 to 4 percent slopes | 13K | Well drained | B | Not limited | Very limited |
| Dunham silty clay loam, 0 to 2 percent slopes | 13K | Poorly drained | B/D | Very limited | Very limited |
| Kidder loam, 4 to 6 percent slopes, eroded | 11K | Well drained | B | Not limited | Very limited |
| Kidami loam, 4 to 6 percent slopes, eroded | 10K | Moderately well drained | C | Somewhat limited | Very limited |
| Dakota loam, 0 to 2 percent slopes | 8K | Well drained | B | Not limited | Very limited |
| Houghton muck, 0 to 2 percent slopes | 8K | Very poorly drained | A/D | Very limited | Very limited |
| Fox silt loam, 2 to 4 percent slopes | 7K | Well drained | B | Not limited | Very limited |
| Grundelein silt loam, 0 to 2 percent slopes | 7K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Kidami silt loam, 2 to 4 percent slopes | 7K | Moderately well drained | C | Somewhat limited | Very limited |
| Water | 7K | Not rated | Not rated | ||
| Warsaw loam, 2 to 4 percent slopes | 7K | Well drained | B | Not limited | Very limited |
| Comfrey loam, 0 to 2 percent slopes, occasionally flooded | 7K | Poorly drained | B/D | Very limited | Very limited |
| Brenton silt loam, 0 to 2 percent slopes | 7K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Waupecan silt loam, 0 to 2 percent slopes | 6K | Well drained | B | Not limited | Very limited |
| Griswold loam, 4 to 6 percent slopes, eroded | 6K | Well drained | B | Not limited | Very limited |
| Elburn silt loam, cool, 0 to 2 percent slopes | 5K | Somewhat poorly drained | C | Very limited | Very limited |
| Kidder loam, 6 to 12 percent slopes, eroded | 5K | Well drained | B | Somewhat limited | Very limited |
| Millstream silt loam, 0 to 2 percent slopes | 5K | Somewhat poorly drained | B/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.
What This Means
Building & Foundations
About 43% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 95% 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.