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USDA SSURGO COUNTY SOIL REFERENCE

Ada County, Idaho Soil Summary

This page summarizes USDA SSURGO mapped soil information for Ada County, Idaho.

Mapped Land Coverage
100%678,885.93 mapped acres of 678,885.91 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
Chilcott-Catchell-Chardoton complex, 0 to 4 percent slopes
Symbol: 4105 • 4.76% of mapped area
Largest estimated component
Chilcott
54,673.38 acres (8.05% of mapped area)
Mapped units & components
446 mapped soil units
Top 15 shown below · 168 component series
Dominant drainage class
Well drained
Highest acreage drainage class
Dominant hydrologic group
Group C
Runoff potential classification
Weighted average slope
8.95%
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.

Top Mapped Soil Units

Showing the 15 largest mapped units, representing 31.71% of mapped soil area.
SymbolMap Unit NameMapped Acres% of Mapped Area
4105Chilcott-Catchell-Chardoton complex, 0 to 4 percent slopes32,334.94.76%
141Purdam silt loam, 0 to 2 percent slopes26,263.593.87%
4004Tadpole-Corder complex, 0 to 2 percent slopes25,761.833.79%
4104Catchell-Chilcott-Banbury complex, 1 to 12 percent slopes16,964.722.5%
4116Elfkin-Dolman-Minveno complex, 1 to 8 percent slopes13,784.252.03%
35Chilcott-Sebree complex, 2 to 4 percent slopes13,656.52.01%
34Chilcott-Sebree complex, 0 to 2 percent slopes12,490.951.84%
4010Tadpole-Purdam-Trevino complex, 0 to 5 percent slopes10,856.271.6%
129Power silt loam, 0 to 2 percent slopes10,196.811.5%
164Scism silt loam, bedrock substratum, 2 to 4 percent slopes9,781.661.44%
38Chilcott-Sebree complex, bedrock substratum, 2 to 4 percent slopes9,343.261.38%
40Colthorp silt loam, 0 to 2 percent slopes9,338.511.38%
4005Corder-Tadpole complex, 2 to 8 percent slopes8,478.891.25%
4114Elfkin-Chilcott-Power complex, 0 to 4 percent slopes8,085.121.19%
1Paulmyers silt loam, 0 to 3 percent slopes7,926.811.17%
41054.76% of mapped area

Chilcott-Catchell-Chardoton complex, 0 to 4 percent slopes

Mapped Area32,334.9 acres
Rank#1 of 446 in county
1413.87% of mapped area

Purdam silt loam, 0 to 2 percent slopes

Mapped Area26,263.59 acres
Rank#2 of 446 in county
40043.79% of mapped area

Tadpole-Corder complex, 0 to 2 percent slopes

Mapped Area25,761.83 acres
Rank#3 of 446 in county
41042.5% of mapped area

Catchell-Chilcott-Banbury complex, 1 to 12 percent slopes

Mapped Area16,964.72 acres
Rank#4 of 446 in county
41162.03% of mapped area

Elfkin-Dolman-Minveno complex, 1 to 8 percent slopes

Mapped Area13,784.25 acres
Rank#5 of 446 in county
352.01% of mapped area

Chilcott-Sebree complex, 2 to 4 percent slopes

Mapped Area13,656.5 acres
Rank#6 of 446 in county
341.84% of mapped area

Chilcott-Sebree complex, 0 to 2 percent slopes

Mapped Area12,490.95 acres
Rank#7 of 446 in county
40101.6% of mapped area

Tadpole-Purdam-Trevino complex, 0 to 5 percent slopes

Mapped Area10,856.27 acres
Rank#8 of 446 in county
1291.5% of mapped area

Power silt loam, 0 to 2 percent slopes

Mapped Area10,196.81 acres
Rank#9 of 446 in county
1641.44% of mapped area

Scism silt loam, bedrock substratum, 2 to 4 percent slopes

Mapped Area9,781.66 acres
Rank#10 of 446 in county
381.38% of mapped area

Chilcott-Sebree complex, bedrock substratum, 2 to 4 percent slopes

Mapped Area9,343.26 acres
Rank#11 of 446 in county
401.38% of mapped area

Colthorp silt loam, 0 to 2 percent slopes

Mapped Area9,338.51 acres
Rank#12 of 446 in county
40051.25% of mapped area

Corder-Tadpole complex, 2 to 8 percent slopes

Mapped Area8,478.89 acres
Rank#13 of 446 in county
41141.19% of mapped area

Elfkin-Chilcott-Power complex, 0 to 4 percent slopes

Mapped Area8,085.12 acres
Rank#14 of 446 in county
11.17% of mapped area

Paulmyers silt loam, 0 to 3 percent slopes

Mapped Area7,926.81 acres
Rank#15 of 446 in county

Estimated Soil Components

Showing the 15 largest estimated component series. Component acreages are estimated from SSURGO map-unit component percentages (comppct_r) applied to spatially measured map-unit acreage.
ComponentDrainage ClassHydrologic GroupEstimated Acres% of Mapped Area
ChilcottWell drainedD54,673.388.05%
PurdamWell drained, Somewhat poorly drainedC39,978.385.89%
PowerWell drainedC31,413.354.63%
ScismWell drainedC24,717.683.64%
TadpoleWell drainedB23,204.063.42%
ElijahWell drainedD, C21,476.253.16%
ColthorpWell drainedD20,050.672.95%
CorderWell drainedD17,463.352.57%
KunatonWell drainedD14,539.532.14%
ChardotonWell drainedD14,495.692.14%
Urban landUnspecifiedUnspecified14,479.942.13%
CatchellWell drainedD14,122.722.08%
McCainWell drainedC13,649.392.01%
SebreeWell drainedD13,227.711.95%
LankbushWell drainedC, A12,315.571.81%
Component acreage is estimated from SSURGO map-unit component percentages. Component values are not independently mapped polygon boundaries.

Chilcott

8.05%
Estimated Acres54,673.38
Drainage ClassWell drained
Hydrologic GroupD

Purdam

5.89%
Estimated Acres39,978.38
Drainage ClassWell drained, Somewhat poorly drained
Hydrologic GroupC

Power

4.63%
Estimated Acres31,413.35
Drainage ClassWell drained
Hydrologic GroupC

Scism

3.64%
Estimated Acres24,717.68
Drainage ClassWell drained
Hydrologic GroupC

Tadpole

3.42%
Estimated Acres23,204.06
Drainage ClassWell drained
Hydrologic GroupB

Elijah

3.16%
Estimated Acres21,476.25
Drainage ClassWell drained
Hydrologic GroupD, C

Colthorp

2.95%
Estimated Acres20,050.67
Drainage ClassWell drained
Hydrologic GroupD

Corder

2.57%
Estimated Acres17,463.35
Drainage ClassWell drained
Hydrologic GroupD

Kunaton

2.14%
Estimated Acres14,539.53
Drainage ClassWell drained
Hydrologic GroupD

Chardoton

2.14%
Estimated Acres14,495.69
Drainage ClassWell drained
Hydrologic GroupD

Urban land

2.13%
Estimated Acres14,479.94
Drainage ClassUnspecified
Hydrologic GroupUnspecified

Catchell

2.08%
Estimated Acres14,122.72
Drainage ClassWell drained
Hydrologic GroupD

McCain

2.01%
Estimated Acres13,649.39
Drainage ClassWell drained
Hydrologic GroupC

Sebree

1.95%
Estimated Acres13,227.71
Drainage ClassWell drained
Hydrologic GroupD

Lankbush

1.81%
Estimated Acres12,315.57
Drainage ClassWell drained
Hydrologic GroupC, A
Component acreage is estimated from SSURGO map-unit component percentages. Component values are not independently mapped polygon boundaries.

Drainage Class Distribution

Well drained70.38%
477,776.54 acres
Somewhat excessively drained5.08%
34,491.34 acres
Unknown / Unmapped4.63%
31,459.04 acres
Somewhat poorly drained2.71%
18,417.57 acres
Excessively drained0.87%
5,878.01 acres
Moderately well drained0.85%
5,748.22 acres
Poorly drained0.12%
843.68 acres
Very poorly drained0.12%
828.87 acres

Hydrologic Soil Group Distribution

Group C32.57%
221,088.91 acres
Group D31.33%
212,717.01 acres
Group B9.02%
61,236.59 acres
Group A8.16%
55,386.27 acres
Group Unknown / Unmapped3.28%
22,289.93 acres
Group A/D0.28%
1,868.7 acres
Group B/D0.12%
834.79 acres
Group C/D0%
21.09 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: 8.95%
Nearly Level (0-2%)41.39%
281,019.41 acres
Gently Sloping (2-8%)23.22%
157,642.65 acres
Moderately Sloping (8-15%)3.23%
21,916.64 acres
Steep (15-30%)4.59%
31,132.49 acres
Very Steep (>30%)9.16%
62,217.94 acres
Unspecified Slope3.17%
21,514.14 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).

Data SourcesMethodology
GEOID 16001 • spatial-mukey-clipped-area-v2