Tonto National Forest, Arizona, Parts of Gila, Maricopa, Pinal and Yavapai Counties
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). 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 Tonto National Forest, Arizona, Parts of Gila, Maricopa, Pinal and Yavapai Counties.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Ustic Haplargids and Typic Torriorthents; cool thermic aridic fan piedmonts | 1.1M | Well drained | C | Very limited | Very limited |
| Lithic Argiustolls, Typic Haplustolls, and Aridic Calciustolls; warm mesic ustic mountains | 917K | Well drained | D | Very limited | Very limited |
| Lithic Argiustolls, Cumulic Haplustolls, rarely flooded, and Typic Ustorthents; warm mesic ustic mountains | 353K | Well drained | C | Very limited | Very limited |
| Typic Haplargids, Ustic Haplocambids, and Ustic Calciargids; warm thermic basins and fan remnants | 324K | Well drained | C | Somewhat limited | Very limited |
| Ustic Haplargids, Ustic Torrifluvents, rarely flooded, and Ustic Haplocambids; warm thermic aridic hills and fans | 97K | Well drained | A | Very limited | Very limited |
| Mined land | 14K | Not rated | Not rated | ||
| Caralampi-Eloma complex, 10 to 60 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Vertic Haplustalfs, Vertic Paleustalfs, and Typic Argiustolls; cool mesic ustic plateaus | 6K | Well drained | C | Very limited | Very limited |
| Ustic Haplocalcids, Ustic Haplocambids, rarely flooded, and Typic Torripsamments, rarely flooded; cool thermic aridic alluvial fans | 5K | Well drained | B | Very limited | Very limited |
| Rock outcrop-Woodcutter complex, tuff, 15 to 50 percent slopes | 4K | D | Not rated | Not rated | |
| Tombstone-Eloma-Pedregosa complex, 5 to 65 percent slopes mlra 38 | 4K | Well drained | A | Very limited | Very limited |
| Cammerman-Rock outcrop complex, 15 to 55 percent slopes mlra 38 | 4K | Well drained | D | Very limited | Very limited |
| Urban land and Haplic Torriarents soils, 2 to 15 percent slopes | 3K | D | Not rated | Not rated | |
| Turkeytrack loam, 1 to 8 percent slopes | 3K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Mabray-Pantak complex, 20 to 70 percent slopes | 3K | Well drained | D | Very limited | Very limited |
| Oracle-Cammerman-Rock outcrop complex, 10 to 50 percent slopes | 2K | Well drained | D | Very limited | Very limited |
| Comoro sandy loam, 0 to 5 percent slopes | 2K | Somewhat excessively drained | A | Very limited | Somewhat limited |
| Urban land and Haplic Torriarents soils, 15 to 40 percent slopes | 2K | D | Not rated | Not rated | |
| Spudrock gravelly loam, 3 to 8 percent slopes | 2K | Well drained | B | Very limited | Very limited |
| Silverstrike-Popcorn-Quillian complex, 15 to 50 percent slopes | 2K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 88% 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 99% 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.