Pima County, Arizona, Eastern Part
The most common soil here is Sahuarita, on about 4% of the land: a very gravelly fine sandy loam, gritty and crumbly. Caralampi and Hayhook come next.
About 97% of the land drains well.
USDA rates 72% of the land very limited for a standard septic drain field, and 50% 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 35% 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 Pima County, Arizona, Eastern 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 C (slow infiltration, moderate runoff). The most common soil order is Aridisols — dry-climate soils with limited organic matter and often calcium carbonate accumulation. 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 Pima County, Arizona, Eastern 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 |
|---|---|---|---|---|---|
| Hayhook-Sahuarita complex, 1 to 5 percent slopes | 79K | Well drained | A | Not limited | Not limited |
| Pantano-Granolite complex, 5 to 25 percent slopes | 75K | Well drained | D | Very limited | Very limited |
| Deloro-Andrada complex, 5 to 35 percent slopes | 65K | Well drained | D | Very limited | Very limited |
| Sahuarita soils, mohave soils and urban land, 1 to 5 percent slopes | 65K | Well drained | C | Somewhat limited | Very limited |
| Oracle-Romero-Rock outcrop complex, 5 to 35 percent slopes | 58K | Well drained | D | Very limited | Very limited |
| Anklam-Cellar-Rock outcrop complex, 15 to 55 percent slopes | 53K | Well drained | D | Very limited | Very limited |
| Lampshire-Romero-Rock outcrop complex, 10 to 65 percent slopes | 49K | Well drained | D | Very limited | Very limited |
| Pinaleno very cobbly sandy loam, 1 to 8 percent slopes | 49K | Well drained | C | Very limited | Very limited |
| Sasabe-Caralampi complex, 1 to 15 percent slopes | 48K | Well drained | C | Somewhat limited | Very limited |
| White House-Caralampi complex, 5 to 25 percent slopes | 47K | Well drained | C | Somewhat limited | Very limited |
| Bucklebar-Sahuarita complex, 0 to 3 percent slopes | 45K | Well drained | B | Somewhat limited | Somewhat limited |
| Mohave soils and urban land, 1 to 8 percent slopes | 44K | Well drained | C | Somewhat limited | Very limited |
| Tubac gravelly loam, 1 to 8 percent slopes | 44K | Well drained | C | Somewhat limited | Very limited |
| Powerline-Kimrose family complex, 10 to 35 percent slopes | 40K | Well drained | B | Very limited | Very limited |
| Hayhook sandy loam, 1 to 5 percent slopes | 39K | Well drained | A | Not limited | Not limited |
| White House gravelly loam, 1 to 8 percent slopes | 38K | Well drained | C | Somewhat limited | Very limited |
| Nolam-Tombstone complex, 8 to 30 percent slopes | 38K | Well drained | B | Somewhat limited | Somewhat limited |
| Pinaleno-Stagecoach complex, 5 to 16 percent slopes | 36K | Well drained | C | Very limited | Very limited |
| Mabray-Deloro-Rock outcrop complex, 20 to 65 percent slopes | 35K | Well drained | D | Very limited | Very limited |
| Arizo-Riverwash complex, 0 to 3 percent slopes | 33K | Excessively 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 50% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 72% 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.