Rock Island County, Illinois
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Rock Island County, Illinois.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Fayette silt loam, glaciated, 2 to 5 percent slopes | 28K | Well drained | B | Somewhat limited | Somewhat limited |
| Water | 18K | Not rated | Not rated | ||
| Muscatune silt loam, 0 to 2 percent slopes | 14K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Hickory-Sylvan-Fayette silt loams, 18 to 30 percent slopes | 12K | Well drained | B | Very limited | Very limited |
| Orion silt loam, 0 to 2 percent slopes, frequently flooded | 9K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Sylvan silty clay loam, 10 to 18 percent slopes, severely eroded | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Hickory-Sylvan silt loams, 35 to 60 percent slopes | 8K | Well drained | B | Very limited | Very limited |
| Orthents, loamy, undulating | 8K | Well drained | C | Not limited | Very limited |
| Sparta loamy sand, Illinois till plain, 0 to 2 percent slopes | 7K | Excessively drained | A | Not limited | Very limited |
| Osco silt loam, 2 to 5 percent slopes | 7K | Well drained | B | Somewhat limited | Somewhat limited |
| Sawmill silty clay loam, 0 to 2 percent slopes, frequently flooded | 7K | Poorly drained | B/D | Very limited | Very limited |
| Coffeen silt loam, 0 to 2 percent slopes, rarely flooded | 6K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Greenbush silt loam, 2 to 5 percent slopes | 6K | Well drained | B | Somewhat limited | Somewhat limited |
| Osco silt loam, 5 to 10 percent slopes, eroded | 5K | Well drained | B | Somewhat limited | Somewhat limited |
| Hickory-Sylvan-Fayette silt loams, 10 to 18 percent slopes, eroded | 5K | Well drained | B | Somewhat limited | Somewhat limited |
| Fluvaquents, loamy, 0 to 2 percent slopes, frequently flooded, long duration | 5K | Poorly drained | B/D | Very limited | Very limited |
| Radford silt loam, 0 to 2 percent slopes, frequently flooded | 5K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Rozetta silt loam, 0 to 2 percent slopes | 5K | Well drained | B | Somewhat limited | Somewhat limited |
| Sylvan silt loam, 18 to 35 percent slopes | 5K | Well drained | B | Very limited | Very limited |
| Lawson silt loam, cool mesic, 0 to 2 percent slopes, frequently flooded | 4K | Somewhat poorly drained | B/D | Very limited | Very limited |
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 52% 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.