USDA SSURGO COUNTY SOIL REFERENCE

Maricopa County, Arizona Soil Summary

This page summarizes USDA SSURGO mapped soil information for Maricopa County, Arizona.

Mapped Land Coverage
72.18%4,261,686.57 mapped acres of 5,904,627.68 Census land acres

Coverage measures mapped SSURGO intersection with Census land geometry. It does not mean that every parcel or point has complete soil information.

Soil at a Glance

Largest mapped soil unit
Ustic Haplargids and Typic Torriorthents; cool thermic aridic fan piedmonts
Symbol: 2039.21% of mapped area
Largest estimated component
Unnamed soils
368,240.48 acres (8.64% of mapped area)
Mapped units & components
15 soil units • 15 component series
Distinct SSURGO map units & series
Dominant drainage class
Well drained
Highest acreage drainage class
Dominant hydrologic group
Group C
Runoff potential classification
Weighted average slope
13.42%
Terrain slope analysis
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County summaries provide regional context across mapped soil units. Address lookup combines available public datasets for the Census-matched location.

Mapped SSURGO Soil Units

Largest mapped soil units in Maricopa County ranked by intersected vector acreage
SymbolMap Unit NameMapped Acres% of Mapped Area
203Ustic Haplargids and Typic Torriorthents; cool thermic aridic fan piedmonts392,342.839.21%
207Lithic Argiustolls, Typic Haplustolls, and Aridic Calciustolls; warm mesic ustic mountains312,900.817.34%
206Lithic Argiustolls, Cumulic Haplustolls, rarely flooded, and Typic Ustorthents; warm mesic ustic mountains120,330.692.82%
201Typic Haplargids, Ustic Haplocambids, and Ustic Calciargids; warm thermic basins and fan remnants110,705.062.6%
7Dateland, Wellton, Rillito, Denure, and Rositas, dry, 0 to 5 percent slopes90,756.842.13%
6Bucklebar-Hayhook-Tubac complex, 0 to 3 percent slopes76,783.461.8%
10Growler, Mohall, Tucson, and Valencia, occasionally flooded, dry, 1 to 3 percent slopes66,138.311.55%
25Tremant, Casa Grande, and Rositas, rarely flooded, occasionally ponded, dry, 0 to 10 percent slopes62,103.881.46%
21Denure-Rillito-Why complex, 1 to 5 percent slopes55,295.531.3%
6Coolidge, Denure, and Rillito, dry, 0 to 5 percent slopes53,379.351.25%
45Nahda-Stagecoach complex, 1 to 15 percent slopes46,548.131.09%
44Mohall-Trix complex, 0 to 1 percent slopes44,599.521.05%
21Lomitas, Rock outcrop, Quilotosa, and Rizzo, dry, 15 to 65 percent slopes42,654.671%
24Superstition, Rositas, and Tucson, dry, 0 to 10 percent slopes42,117.430.99%
13Gunsight, Chuckawalla, and Carrizo, occasionally flooded, dry, 1 to 10 percent slopes41,591.790.98%

Estimated Soil Components

Component acreage estimated from SSURGO component percentages
ComponentDrainage ClassHydrologic GroupEstimated Acres% of Mapped Area
Unnamed soilsUnspecifiedUnspecified368,240.488.64%
Ustic HaplargidsWell drainedC327,456.337.68%
Lithic ArgiustollsWell drainedD220,227.725.17%
Rock outcropUnspecifiedD161,448.33.79%
GunsightSomewhat excessively drainedA, B129,849.883.05%
DenureSomewhat excessively drained, Well drainedA, B127,513.162.99%
MohallWell drainedC124,445.62.92%
RillitoSomewhat excessively drained, Well drainedB, A113,067.572.65%
GilmanWell drainedA, C, B96,938.692.27%
Typic HaplustollsWell drainedC93,870.242.2%
CarrizoExcessively drainedA87,408.852.05%
Typic TorriorthentsExcessively drainedA78,468.571.84%
MomoliSomewhat excessively drained, Well drainedA, B73,502.771.72%
Casa GrandeWell drainedC71,996.241.69%
QuilotosaSomewhat excessively drainedD68,236.741.6%
Component acreage is estimated from SSURGO map-unit component percentages. Component values are not independently mapped polygon boundaries.

Drainage Class Distribution

Well drained64.4%
2,744,445.28 acres
Somewhat excessively drained17.43%
742,703.69 acres
Unknown / Unmapped13.36%
569,245.12 acres
Excessively drained4.81%
205,045.6 acres
Moderately well drained0%
155.24 acres
Poorly drained0%
40.79 acres
Very poorly drained0%
35.71 acres
Somewhat poorly drained0%
15.15 acres

Hydrologic Soil Group Distribution

Group C32.59%
1,388,849.01 acres
Group A23.89%
1,018,238.07 acres
Group D21.92%
934,364.94 acres
Group B11.17%
475,906.96 acres
Group Unknown / Unmapped10.43%
444,291.89 acres
Group A/D0%
35.71 acres

Hydrologic soil groups are USDA/NRCS classifications related to runoff potential under specified soil conditions. They are not a property-level flood-risk rating.

Slope Characteristics

Weighted Average Slope: 13.42%
Nearly Level (0-2%)36.4%
1,551,304.82 acres
Gently Sloping (2-8%)19.8%
843,738.85 acres
Moderately Sloping (8-15%)7.18%
306,118.81 acres
Steep (15-30%)4.24%
180,659.06 acres
Very Steep (>30%)19.61%
835,808.94 acres
Unspecified Slope12.77%
544,056.1 acres

Sources & Methodology

USDA NRCS SSURGO

Mapped soil units, components, drainage classes, hydrologic groups, and slope ratings derived from official Soil Data Access REST services.

U.S. Census Bureau TIGER/Line

County land geometry used for county-level coverage calculation.

Coverage Method

Mapped acreage is calculated from true spatial vector intersection of county land geometry and SSURGO mapped soil polygons using NAD83 / CONUS Albers Equal Area projection (EPSG:5070).