San Juan County, Utah, Central Part
The most common soil here is Rizno, on about 17% of the land: a fine sandy loam, gritty and crumbly. Skos and Strych come next.
About 84% of the land drains well.
USDA rates 73% of the land very limited for a standard septic drain field, and 69% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 2% of the land floods occasionally or more, and bedrock lies within 40 inches under 82% 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 San Juan County, Utah, Central Part, 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 D (very slow infiltration, high runoff). The most common soil order is Entisols — young soils with little profile development, often on floodplains or steep slopes. 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 San Juan County, Utah, Central Part. 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 |
|---|---|---|---|---|---|
| Rizno-Barx-Yarts complex | 126K | Well drained | D | Very limited | Very limited |
| Rizno-Rock outcrop complex | 81K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Piute-Skos association | 74K | D | Not rated | Not rated | |
| Rizno-Skos-Rock outcrop complex | 71K | Well drained | D | Very limited | Very limited |
| Rizno-Littlenan-Bodot association | 70K | Well drained | D | Very limited | Very limited |
| Myton family-Skos-Rock outcrop association | 70K | Well drained | D | Very limited | Very limited |
| Rizno-Ruinpoint-Rock outcrop complex | 65K | Well drained | D | Not rated | Not rated |
| Bodot-Strych-Skos association | 64K | Well drained | C | Very limited | Very limited |
| Skos,warm-Rock outcrop complex | 45K | Well drained | D | Very limited | Very limited |
| Bluechief-Limeridge-Nakai complex, 1 to 6 percent slopes | 41K | Well drained | B | Very limited | Very limited |
| Rock outcrop-Strych-Rizno association | 41K | Well drained | D | Very limited | Very limited |
| Strych-Rizno-Strych, very steep association | 36K | Well drained | A | Very limited | Very limited |
| Rizno-Cahona-Rock outcrop complex | 34K | Well drained | D | Very limited | Very limited |
| Moenkopie-Moenkopie,warm, complex | 34K | Well drained | D | Very limited | Very limited |
| Ruinpoint-Cahona association | 31K | Well drained | B | Somewhat limited | Somewhat limited |
| Moenkopie-Rock outcrop complex | 30K | D | Not rated | Not rated | |
| Piute-Sheppard-Rock outcrop association | 30K | D | Not rated | Very limited | |
| Littlenan-Ruinpoint-Rizno association, 1 to 20 percent slopes | 29K | Well drained | D | Very limited | Very limited |
| Milok-Mivida complex | 25K | Well drained | A | Not limited | Not limited |
| Strych, warm-Skos, warm-Badland complex | 24K | Well drained | A | 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 69% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 73% 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.