Tucson-Avra Valley Area, Arizona

Survey Area AZ668• Arizona

The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low 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 Tucson-Avra Valley Area, Arizona. 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
Anthony gravelly sandy loam,1 to 3 percent slopes	14K	Well drained	A	Very limited	Somewhat limited
Grabe loam	14K	Well drained	B	Very limited	Somewhat limited
Gila loam, 0 to 1 percent slopes	10K	Well drained	B	Very limited	Somewhat limited
Anway loam	9K	Well drained	B	Very limited	Somewhat limited
Anway silty clay loam	8K	Well drained	B	Very limited	Somewhat limited
Grabe silty clay loam	7K	Well drained	C	Very limited	Somewhat limited
Comoro sandy loam	6K	Well drained	A	Very limited	Somewhat limited
Valencia sandy loam, 0 to 1 percent slopes	6K	Well drained	C	Very limited	Very limited
Anthony sandy loam, 0 to 1 percent slopes	5K	Well drained	A	Very limited	Somewhat limited
Pima silty clay loam	5K	Well drained	C	Very limited	Very limited
Rough broken land-Palos Verdes complex, 0 to 60 percent slopes	5K	Well drained		Very limited	Very limited
Valencia-Sonoita sandy loams, 1 to 5 percent slopes	5K	Well drained	C	Very limited	Very limited
Gravelly alluvial land	5K	Excessively drained		Very limited	Very limited
Sonoita sandy loam, 0 to 1 percent slopes	4K	Well drained	A	Somewhat limited	Not limited
Anthony and Sonoita soils, 0 to 5 percent slopes	4K	Well drained	A	Very limited	Somewhat limited
Vinton-anthony sandy loams	4K	Well drained	A	Very limited	Very limited
Anthony sandy loam, 1 to 3 percent slopes	4K	Well drained	A	Very limited	Somewhat limited
Mohave clay loam	4K	Well drained	C	Somewhat limited	Very limited
Vekol silty clay loam	3K	Well drained	C	Very limited	Very limited
Sonoita sandy clay loam	3K	Well drained	A	Somewhat limited	Not 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.

Aridisols

Dry-climate soils with low organic matter. Often have caliche layers that make excavation difficult. Low shrink-swell is good for foundations.

Entisols

Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

Mollisols

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

What This Means

Building & Foundations

About 91% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 28% of soils have significant septic limitations, while others are more suitable. A perc test is essential — conditions vary across the area.

Gardening & Agriculture

Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.