BasementSoil

Illinois: basement moisture and foundation risk by county

102 counties, ranked by our combined index. Highest combined risk is Crawford County (64), lowest is Jo Daviess County (27). The worst soil for foundation cracks specifically is in Williamson County.

Where in Illinois the ground is worse

Every county in the state, coloured by the soil values below. Click a county to open its report; switch what the colour means with the buttons. The pattern is geology, not administration — risk stops at the edge of a physiographic region, not at a county line.

Adams County, IL — combined 52/100, moisture 53, movement 39, water table 66Alexander County, IL — combined 54/100, moisture 53, movement 48, water table 66Bond County, IL — combined 56/100, moisture 52, movement 42, water table 82Boone County, IL — combined 56/100, moisture 52, movement 53, water table 66Brown County, IL — combined 56/100, moisture 53, movement 41, water table 82Bureau County, IL — combined 53/100, moisture 56, movement 38, water table 66Calhoun County, IL — combined 51/100, moisture 49, movement 44, water table 66Carroll County, IL — combined 28/100, moisture 33, movement 20, water table 30Cass County, IL — combined 58/100, moisture 53, movement 47, water table 82Champaign County, IL — combined 51/100, moisture 52, movement 39, water table 66Christian County, IL — combined 52/100, moisture 53, movement 30, water table 82Clark County, IL — combined 55/100, moisture 56, movement 45, water table 66Clay County, IL — combined 54/100, moisture 51, movement 49, water table 66Clinton County, IL — combined 60/100, moisture 50, movement 57, water table 82Coles County, IL — combined 56/100, moisture 56, movement 49, water table 66Cook County, IL — combined 53/100, moisture 53, movement 31, water table 82Crawford County, IL — combined 64/100, moisture 52, movement 68, water table 82Cumberland County, IL — combined 59/100, moisture 53, movement 61, water table 66De Witt County, IL — combined 52/100, moisture 52, movement 55, water table 46DeKalb County, IL — combined 50/100, moisture 53, movement 34, water table 66Douglas County, IL — combined 49/100, moisture 53, movement 31, water table 66DuPage County, IL — combined 51/100, moisture 55, movement 48, water table 46Edgar County, IL — combined 54/100, moisture 55, movement 57, water table 46Edwards County, IL — combined 56/100, moisture 54, movement 41, water table 82Effingham County, IL — combined 61/100, moisture 54, movement 66, water table 66Fayette County, IL — combined 57/100, moisture 51, movement 58, water table 66Ford County, IL — combined 52/100, moisture 56, movement 35, water table 66Franklin County, IL — combined 53/100, moisture 54, movement 43, water table 66Fulton County, IL — combined 60/100, moisture 54, movement 52, water table 82Gallatin County, IL — combined 63/100, moisture 54, movement 62, water table 82Greene County, IL — combined 57/100, moisture 54, movement 43, water table 82Grundy County, IL — combined 49/100, moisture 55, movement 29, water table 66Hamilton County, IL — combined 56/100, moisture 53, movement 43, water table 82Hancock County, IL — combined 55/100, moisture 53, movement 38, water table 82Hardin County, IL — combined 49/100, moisture 49, movement 37, water table 66Henderson County, IL — combined 48/100, moisture 52, movement 30, water table 66Henry County, IL — combined 56/100, moisture 53, movement 53, water table 66Iroquois County, IL — combined 53/100, moisture 57, movement 38, water table 66Jackson County, IL — combined 62/100, moisture 53, movement 61, water table 82Jasper County, IL — combined 63/100, moisture 54, movement 62, water table 82Jefferson County, IL — combined 56/100, moisture 50, movement 45, water table 82Jersey County, IL — combined 62/100, moisture 49, movement 65, water table 82Jo Daviess County, IL — combined 27/100, moisture 34, movement 16, water table 30Johnson County, IL — combined 60/100, moisture 51, movement 67, water table 66Kane County, IL — combined 54/100, moisture 56, movement 42, water table 66Kankakee County, IL — combined 58/100, moisture 54, movement 57, water table 66Kendall County, IL — combined 57/100, moisture 57, movement 52, water table 66Knox County, IL — combined 56/100, moisture 53, movement 52, water table 66LaSalle County, IL — combined 52/100, moisture 55, movement 39, water table 66Lake County, IL — combined 57/100, moisture 57, movement 52, water table 66Lawrence County, IL — combined 64/100, moisture 53, movement 67, water table 82Lee County, IL — combined 56/100, moisture 55, movement 50, water table 66Livingston County, IL — combined 50/100, moisture 53, movement 34, water table 66Logan County, IL — combined 51/100, moisture 53, movement 38, water table 66Macon County, IL — combined 47/100, moisture 56, movement 34, water table 46Macoupin County, IL — combined 57/100, moisture 54, movement 42, water table 82Madison County, IL — combined 58/100, moisture 51, movement 52, water table 82Marion County, IL — combined 59/100, moisture 53, movement 50, water table 82Marshall County, IL — combined 51/100, moisture 54, movement 36, water table 66Mason County, IL — combined 49/100, moisture 53, movement 31, water table 66Massac County, IL — combined 51/100, moisture 51, movement 39, water table 66McDonough County, IL — combined 50/100, moisture 53, movement 35, water table 66McHenry County, IL — combined 50/100, moisture 56, movement 45, water table 46McLean County, IL — combined 51/100, moisture 57, movement 32, water table 66Menard County, IL — combined 60/100, moisture 56, movement 50, water table 82Mercer County, IL — combined 53/100, moisture 56, movement 39, water table 66Monroe County, IL — combined 57/100, moisture 49, movement 61, water table 66Montgomery County, IL — combined 58/100, moisture 53, movement 59, water table 66Morgan County, IL — combined 52/100, moisture 57, movement 34, water table 66Moultrie County, IL — combined 49/100, moisture 53, movement 32, water table 66Ogle County, IL — combined 53/100, moisture 57, movement 38, water table 66Peoria County, IL — combined 50/100, moisture 56, movement 44, water table 46Perry County, IL — combined 57/100, moisture 53, movement 55, water table 66Piatt County, IL — combined 53/100, moisture 54, movement 41, water table 66Pike County, IL — combined 55/100, moisture 53, movement 39, water table 82Pope County, IL — combined 60/100, moisture 52, movement 57, water table 82Pulaski County, IL — combined 56/100, moisture 53, movement 54, water table 66Putnam County, IL — combined 51/100, moisture 54, movement 37, water table 66Randolph County, IL — combined 52/100, moisture 53, movement 42, water table 66Richland County, IL — combined 53/100, moisture 51, movement 46, water table 66Rock Island County, IL — combined 51/100, moisture 52, movement 38, water table 66Saline County, IL — combined 55/100, moisture 51, movement 40, water table 82Sangamon County, IL — combined 54/100, moisture 53, movement 48, water table 66Schuyler County, IL — combined 56/100, moisture 55, movement 51, water table 66Scott County, IL — combined 50/100, moisture 57, movement 30, water table 66Shelby County, IL — combined 62/100, moisture 56, movement 56, water table 82St. Clair County, IL — combined 53/100, moisture 50, movement 49, water table 66Stark County, IL — combined 52/100, moisture 54, movement 38, water table 66Stephenson County, IL — combined 34/100, moisture 37, movement 34, water table 30Tazewell County, IL — combined 56/100, moisture 53, movement 54, water table 66Union County, IL — combined 55/100, moisture 50, movement 55, water table 66Vermilion County, IL — combined 59/100, moisture 53, movement 51, water table 82Wabash County, IL — combined 60/100, moisture 52, movement 66, water table 66Warren County, IL — combined 51/100, moisture 52, movement 39, water table 66Washington County, IL — combined 60/100, moisture 50, movement 57, water table 82Wayne County, IL — combined 53/100, moisture 54, movement 43, water table 66White County, IL — combined 55/100, moisture 49, movement 54, water table 66Whiteside County, IL — combined 54/100, moisture 53, movement 34, water table 82Will County, IL — combined 57/100, moisture 54, movement 56, water table 66Williamson County, IL — combined 61/100, moisture 53, movement 69, water table 66Winnebago County, IL — combined 57/100, moisture 56, movement 52, water table 66Woodford County, IL — combined 46/100, moisture 56, movement 31, water table 46
  • Low (0–27)
  • Moderate (28–49)
  • Elevated (50–74)
  • High (75–100)

County boundaries: US Census TIGER (public domain), simplified for display. Colours are our index from USDA SSURGO fields where loaded, otherwise from our regional model — each county page states which. How the index is calculated.

CountyIndexMoistureCracksWater tableRegion
Crawford County64526882Dissected till plain with a claypan
Lawrence County64536782Dissected till plain with a claypan
Gallatin County63546282Dissected till plain with a claypan
Jasper County63546282Dissected till plain with a claypan
Jackson County62536182Dissected till plain with a claypan
Jersey County62496582Dissected till plain with a claypan
Shelby County62565682Wisconsinan till plain
Effingham County61546666Dissected till plain with a claypan
Williamson County61536966Dissected till plain with a claypan
Clinton County60505782Dissected till plain with a claypan
Fulton County60545282Wisconsinan till plain
Johnson County60516766Dissected till plain with a claypan
Menard County60565082Wisconsinan till plain
Pope County60525782Dissected till plain with a claypan
Wabash County60526666Dissected till plain with a claypan
Washington County60505782Dissected till plain with a claypan
Cumberland County59536166Dissected till plain with a claypan
Marion County59535082Dissected till plain with a claypan
Vermilion County59535182Wisconsinan till plain
Cass County58534782Wisconsinan till plain
Kankakee County58545766Wisconsinan till plain
Madison County58515282Dissected till plain with a claypan
Montgomery County58535966Dissected till plain with a claypan
Fayette County57515866Dissected till plain with a claypan
Greene County57544382Wisconsinan till plain
Kendall County57575266Wisconsinan till plain
Lake County57575266Wisconsinan till plain
Macoupin County57544282Dissected till plain with a claypan
Monroe County57496166Dissected till plain with a claypan
Perry County57535566Dissected till plain with a claypan
Will County57545666Wisconsinan till plain
Winnebago County57565266Wisconsinan till plain
Bond County56524282Dissected till plain with a claypan
Boone County56525366Wisconsinan till plain
Brown County56534182Wisconsinan till plain
Coles County56564966Wisconsinan till plain
Edwards County56544182Dissected till plain with a claypan
Hamilton County56534382Dissected till plain with a claypan
Henry County56535366Wisconsinan till plain
Jefferson County56504582Dissected till plain with a claypan
Knox County56535266Wisconsinan till plain
Lee County56555066Wisconsinan till plain
Pulaski County56535466Dissected till plain with a claypan
Schuyler County56555166Wisconsinan till plain
Tazewell County56535466Wisconsinan till plain
Clark County55564566Wisconsinan till plain
Hancock County55533882Wisconsinan till plain
Pike County55533982Wisconsinan till plain
Saline County55514082Dissected till plain with a claypan
Union County55505566Dissected till plain with a claypan
White County55495466Dissected till plain with a claypan
Alexander County54534866Dissected till plain with a claypan
Clay County54514966Dissected till plain with a claypan
Edgar County54555746Wisconsinan till plain
Kane County54564266Wisconsinan till plain
Sangamon County54534866Wisconsinan till plain
Whiteside County54533482Wisconsinan till plain
Bureau County53563866Wisconsinan till plain
Cook County53533182Wisconsinan till plain
Franklin County53544366Dissected till plain with a claypan
Iroquois County53573866Wisconsinan till plain
Mercer County53563966Wisconsinan till plain
Ogle County53573866Wisconsinan till plain
Piatt County53544166Wisconsinan till plain
Richland County53514666Dissected till plain with a claypan
St. Clair County53504966Dissected till plain with a claypan
Wayne County53544366Dissected till plain with a claypan
Adams County52533966Wisconsinan till plain
Christian County52533082Wisconsinan till plain
De Witt County52525546Wisconsinan till plain
Ford County52563566Wisconsinan till plain
LaSalle County52553966Wisconsinan till plain
Morgan County52573466Wisconsinan till plain
Randolph County52534266Dissected till plain with a claypan
Stark County52543866Wisconsinan till plain
Calhoun County51494466Dissected till plain with a claypan
Champaign County51523966Wisconsinan till plain
DuPage County51554846Wisconsinan till plain
Logan County51533866Wisconsinan till plain
Marshall County51543666Wisconsinan till plain
Massac County51513966Dissected till plain with a claypan
McLean County51573266Wisconsinan till plain
Putnam County51543766Wisconsinan till plain
Rock Island County51523866Wisconsinan till plain
Warren County51523966Wisconsinan till plain
DeKalb County50533466Wisconsinan till plain
Livingston County50533466Wisconsinan till plain
McDonough County50533566Wisconsinan till plain
McHenry County50564546Wisconsinan till plain
Peoria County50564446Wisconsinan till plain
Scott County50573066Wisconsinan till plain
Douglas County49533166Wisconsinan till plain
Grundy County49552966Wisconsinan till plain
Hardin County49493766Dissected till plain with a claypan
Mason County49533166Wisconsinan till plain
Moultrie County49533266Wisconsinan till plain
Henderson County48523066Wisconsinan till plain
Macon County47563446Wisconsinan till plain
Woodford County46563146Wisconsinan till plain
Stephenson County34373430Driftless Area
Carroll County28332030Driftless Area
Jo Daviess County27341630Driftless Area

Values from USDA NRCS SSURGO where available, otherwise our regional model — each county page states which. Methodology.

The physiographic regions inside Illinois

State lines are political; soil follows geology. These are the distinct ground types inside Illinois and why each behaves the way it does.

Wisconsinan till plain

The classic American basement belt. Below the topsoil sits dense till that water barely penetrates, so infiltrating water travels sideways along it until it meets the first vertical obstruction — typically a basement wall.

60 counties: Adams County, Boone County, Brown County, Bureau County, Cass County, Champaign County, Christian County, Clark County, Coles County, Cook County, De Witt County, DeKalb County, Douglas County, DuPage County, Edgar County, Ford County, Fulton County, Greene County, Grundy County, Hancock County, Henderson County, Henry County, Iroquois County, Kane County, Kankakee County, Kendall County, Knox County, LaSalle County, Lake County, Lee County, Livingston County, Logan County, Macon County, Marshall County, Mason County, McDonough County, McHenry County, McLean County, Menard County, Mercer County, Morgan County, Moultrie County, Ogle County, Peoria County, Piatt County, Pike County, Putnam County, Rock Island County, Sangamon County, Schuyler County, Scott County, Shelby County, Stark County, Tazewell County, Vermilion County, Warren County, Whiteside County, Will County, Winnebago County, Woodford County

Dissected till plain with a claypan

The claypan is a hard clay layer a few tens of centimetres under the lawn. Water sits on it and spreads sideways. The typical symptom is seepage through the upper part of the wall rather than at the floor.

39 counties: Alexander County, Bond County, Calhoun County, Clay County, Clinton County, Crawford County, Cumberland County, Edwards County, Effingham County, Fayette County, Franklin County, Gallatin County, Hamilton County, Hardin County, Jackson County, Jasper County, Jefferson County, Jersey County, Johnson County, Lawrence County, Macoupin County, Madison County, Marion County, Massac County, Monroe County, Montgomery County, Perry County, Pope County, Pulaski County, Randolph County, Richland County, Saline County, St. Clair County, Union County, Wabash County, Washington County, Wayne County, White County, Williamson County

Driftless Area

The region the ice sheets missed. Slope, permeable loess, deep water table. Soil-driven basement risk is low here; the problems are surface runoff arriving from the hillside rather than groundwater pushing in.

3 counties: Carroll County, Jo Daviess County, Stephenson County

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