Coos County, Oregon
The most common soil here is Preacher, on about 14% of the land: a medial clay loam, firm and a little sticky. Bohannon and Umpcoos come next.
About 87% of the land drains well, and 5% stays wet for long stretches; groundwater comes within two feet of the surface under 10% of it.
USDA rates 97% of the land very limited for a standard septic drain field, and 94% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 4% of the land floods occasionally or more, and bedrock lies within 40 inches under 54% of it.
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 Coos County, Oregon, 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 Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Coos County, Oregon. 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 |
|---|---|---|---|---|---|
| Milbury-Bohannon-Umpcoos association, 50 to 80 percent slopes | 125K | Well drained | B | Very limited | Very limited |
| Preacher-Bohannon loams, 60 to 90 percent slopes | 106K | Well drained | B | Very limited | Very limited |
| Preacher-Bohannon loams, 30 to 60 percent slopes | 77K | Well drained | B | Very limited | Very limited |
| Digger-Preacher-Umpcoos association, 50 to 80 percent slopes | 65K | Well drained | B | Very limited | Very limited |
| Umpcoos-Rock outcrop association, 70 to 99 percent slopes | 44K | Well drained | D | Very limited | Very limited |
| Digger-Umpcoos-Rock outcrop association, 50 to 90 percent slopes | 44K | Well drained | D | Very limited | Very limited |
| Etelka-Whobrey-Remote complex, 30 to 60 percent slopes | 36K | Moderately well drained | C | Very limited | Very limited |
| Remote-Digger-Preacher complex, 30 to 50 percent slopes | 35K | Well drained | B | Very limited | Very limited |
| Templeton silt loam, 30 to 50 percent slopes | 33K | Well drained | B | Very limited | Very limited |
| Preacher-Blachly association, 30 to 60 percent slopes | 28K | Well drained | B | Very limited | Very limited |
| Templeton silt loam, 7 to 30 percent slopes | 28K | Well drained | B | Very limited | Very limited |
| Preacher-Bohannon loams, 3 to 30 percent slopes | 27K | Well drained | B | Very limited | Very limited |
| Rinearson silt loam, 30 to 50 percent slopes | 25K | Well drained | B | Very limited | Very limited |
| Water | 19K | Not rated | Not rated | ||
| Preacher-Blachly association, 12 to 30 percent slopes | 16K | Well drained | B | Very limited | Very limited |
| Preacher-Blachly-Digger association, 30 to 60 percent slopes | 13K | Well drained | B | Very limited | Very limited |
| Etelka silt loam, 30 to 50 percent slopes | 12K | Moderately well drained | C | Very limited | Very limited |
| Millicoma-Templeton complex, 50 to 75 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Honeygrove silty clay loam, 30 to 50 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Kirkendall silt loam | 10K | Well drained | B | 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 94% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 97% 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.