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Illinois soil by county

Across Illinois's mapped land, shrink-swell clay limits houses without basements on 31% and a shallow water table limits basements on 70%.

Highest clay shares: Christian County (72%), Douglas County (72%), De Witt County (69%), Montgomery County (68%), Moultrie County (68%). Highest water-table shares: Ford County (98%), DeKalb County (98%), Livingston County (96%), Douglas County (96%), Hamilton County (95%).

Data as of September 22, 2026 · 102 counties

Adams County: 36%Alexander County: 19%Bond County: 47%Boone County: 6%Brown County: 29%Bureau County: 25%Calhoun County: 4%Carroll County: 13%Cass County: 13%Champaign County: 26%Christian County: 72%Clark County: 29%Clay County: 44%Clinton County: 44%Coles County: 19%Cook County: 25%Crawford County: 43%Cumberland County: 39%De Witt County: 69%DeKalb County: 28%Douglas County: 72%DuPage County: 33%Edgar County: 16%Edwards County: 21%Effingham County: 43%Fayette County: 35%Ford County: 55%Franklin County: 31%Fulton County: 24%Gallatin County: 31%Greene County: 20%Grundy County: 30%Hamilton County: 23%Hancock County: 48%Hardin County: 1%Henderson County: 13%Henry County: 19%Iroquois County: 44%Jackson County: 26%Jasper County: 51%Jefferson County: 26%Jersey County: 22%Jo Daviess County: 17%Johnson County: 2%Kane County: 8%Kankakee County: 19%Kendall County: 26%Knox County: 41%Lake County: 16%LaSalle County: 37%Lawrence County: 23%Lee County: 14%Livingston County: 53%Logan County: 45%Macon County: 57%Macoupin County: 62%Madison County: 33%Marion County: 40%Marshall County: 36%Mason County: 3%Massac County: 8%McDonough County: 63%McHenry County: 2%McLean County: 54%Menard County: 27%Mercer County: 15%Monroe County: 20%Montgomery County: 68%Morgan County: 43%Moultrie County: 68%Ogle County: 10%Peoria County: 29%Perry County: 24%Piatt County: 57%Pike County: 9%Pope County: 2%Pulaski County: 10%Putnam County: 23%Randolph County: 24%Richland County: 44%Rock Island County: 6%Saline County: 20%Sangamon County: 58%Schuyler County: 31%Scott County: 27%Shelby County: 38%St. Clair County: 28%Stark County: 36%Stephenson County: 13%Tazewell County: 33%Union County: 10%Vermilion County: 34%Wabash County: 14%Warren County: 35%Washington County: 36%Wayne County: 26%White County: 12%Whiteside County: 2%Will County: 24%Williamson County: 16%Winnebago County: 9%Woodford County: 49%
Expansive clay: share of mapped land where shrink-swell clay limits houses without basementsunder 10%10-25%25-40%40-60%60%+
Adams County: 70%Alexander County: 48%Bond County: 86%Boone County: 55%Brown County: 38%Bureau County: 53%Calhoun County: 25%Carroll County: 17%Cass County: 45%Champaign County: 94%Christian County: 86%Clark County: 77%Clay County: 91%Clinton County: 88%Coles County: 85%Cook County: 59%Crawford County: 81%Cumberland County: 84%De Witt County: 87%DeKalb County: 98%Douglas County: 96%DuPage County: 90%Edgar County: 83%Edwards County: 92%Effingham County: 87%Fayette County: 81%Ford County: 98%Franklin County: 88%Fulton County: 38%Gallatin County: 67%Greene County: 51%Grundy County: 85%Hamilton County: 95%Hancock County: 72%Hardin County: 41%Henderson County: 43%Henry County: 48%Iroquois County: 93%Jackson County: 62%Jasper County: 89%Jefferson County: 87%Jersey County: 53%Jo Daviess County: 20%Johnson County: 78%Kane County: 82%Kankakee County: 80%Kendall County: 85%Knox County: 41%Lake County: 87%LaSalle County: 84%Lawrence County: 78%Lee County: 66%Livingston County: 96%Logan County: 71%Macon County: 88%Macoupin County: 78%Madison County: 73%Marion County: 89%Marshall County: 66%Mason County: 42%Massac County: 79%McDonough County: 70%McHenry County: 54%McLean County: 85%Menard County: 51%Mercer County: 44%Monroe County: 59%Montgomery County: 88%Morgan County: 54%Moultrie County: 89%Ogle County: 35%Peoria County: 37%Perry County: 75%Piatt County: 94%Pike County: 56%Pope County: 67%Pulaski County: 72%Putnam County: 50%Randolph County: 64%Richland County: 93%Rock Island County: 32%Saline County: 86%Sangamon County: 72%Schuyler County: 46%Scott County: 47%Shelby County: 82%St. Clair County: 73%Stark County: 52%Stephenson County: 24%Tazewell County: 53%Union County: 49%Vermilion County: 90%Wabash County: 74%Warren County: 54%Washington County: 91%Wayne County: 94%White County: 75%Whiteside County: 40%Will County: 85%Williamson County: 74%Winnebago County: 28%Woodford County: 81%
High water table: share of mapped land where a shallow water table limits basementsunder 10%10-25%25-40%40-60%60%+

Every county in Illinois

Select a column heading to sort.
Adams County 36% 70% 0% 39 1965
Alexander County 19% 48% 0% 49 1969
Bond County 47% 86% 0% 5 1975
Boone County 6% 55% 0% 10 1986
Brown County 29% 38% 0% 1 1960
Bureau County 25% 53% 0% 4 1958
Calhoun County 4% 25% 0% 102 1968
Carroll County 13% 17% 0% 2 1957
Cass County 13% 45% 0% 6 1968
Champaign County 26% 94% 0% 13 1981
Christian County 72% 86% 0% 2 1963
Clark County 29% 77% 0% 4 1971
Clay County 44% 91% 0% 1 1972
Clinton County 44% 88% 0% 4 1977
Coles County 19% 85% 0% 17 1971
Cook County 25% 59% 0% 1,057 1961
Crawford County 43% 81% 0% 0 1965
Cumberland County 39% 84% 0% 0 1970
De Witt County 69% 87% 0% 0 1958
DeKalb County 28% 98% 0% 7 1978
Douglas County 72% 96% 0% 2 1967
DuPage County 33% 90% 0% 198 1978
Edgar County 16% 83% 0% 1 1964
Edwards County 21% 92% 0% 0 1970
Effingham County 43% 87% 0% 1 1978
Fayette County 35% 81% 0% 0 1972
Ford County 55% 98% 0% 2 1955
Franklin County 31% 88% 0% 7 1963
Fulton County 24% 38% 0% 4 1960
Gallatin County 31% 67% 0% 1 1969
Greene County 20% 51% 0% 2 1957
Grundy County 30% 85% 0% 52 1990
Hamilton County 23% 95% 0% 0 1970
Hancock County 48% 72% 0% 23 1964
Hardin County 1% 41% 0% 0 1974
Henderson County 13% 43% 0% 46 1972
Henry County 19% 48% 0% 7 1961
Iroquois County 44% 93% 0% 206 1960
Jackson County 26% 62% 0% 10 1976
Jasper County 51% 89% 0% 1 1975
Jefferson County 26% 87% 0% 7 1977
Jersey County 22% 53% 0% 121 1975
Jo Daviess County 17% 20% 0% 12 1976
Johnson County 2% 78% 0% 1 1985
Kane County 8% 82% 0% 71 1985
Kankakee County 19% 80% 0% 91 1972
Kendall County 26% 85% 0% 6 2001
Knox County 41% 41% 0% 2 1957
LaSalle County 37% 84% 0% 27 1963
Lake County 16% 87% 0% 655 1983
Lawrence County 23% 78% 0% 7 1963
Lee County 14% 66% 0% 2 1960
Livingston County 53% 96% 0% 10 1961
Logan County 45% 71% 0% 4 1964
Macon County 57% 88% 0% 6 1964
Macoupin County 62% 78% 0% 1 1966
Madison County 33% 73% 0% 131 1971
Marion County 40% 89% 0% 2 1973
Marshall County 36% 66% 0% 8 1961
Mason County 3% 42% 0% 9 1959
Massac County 8% 79% 0% 16 1975
McDonough County 63% 70% 0% 0 1965
McHenry County 2% 54% 0% 152 1989
McLean County 54% 85% 0% 27 1981
Menard County 27% 51% 0% 2 1976
Mercer County 15% 44% 0% 1 1962
Monroe County 20% 59% 0% 11 1990
Montgomery County 68% 88% 0% 0 1964
Morgan County 43% 54% 0% 5 1965
Moultrie County 68% 89% 0% 1 1968
Ogle County 10% 35% 0% 30 1972
Peoria County 29% 37% 0% 103 1966
Perry County 24% 75% 0% 4 1973
Piatt County 57% 94% 0% 0 1973
Pike County 9% 56% 0% 12 1961
Pope County 2% 67% 0% 0 1986
Pulaski County 10% 72% 0% 8 1969
Putnam County 23% 50% 0% 3 1975
Randolph County 24% 64% 0% 20 1972
Richland County 44% 93% 0% 0 1973
Rock Island County 6% 32% 0% 240 1962
Saline County 20% 86% 0% 9 1971
Sangamon County 58% 72% 0% 15 1974
Schuyler County 31% 46% 0% 0 1971
Scott County 27% 47% 0% 0 1963
Shelby County 38% 82% 0% 0 1966
St. Clair County 28% 73% 0% 298 1975
Stark County 36% 52% 0% 0 1956
Stephenson County 13% 24% 0% 89 1960
Tazewell County 33% 53% 0% 16 1969
Union County 10% 49% 0% 6 1975
Vermilion County 34% 90% 0% 21 1957
Wabash County 14% 74% 0% 0 1970
Warren County 35% 54% 0% 2 1956
Washington County 36% 91% 0% 3 1972
Wayne County 26% 94% 0% 2 1974
White County 12% 75% 0% 8 1962
Whiteside County 2% 40% 0% 48 1961
Will County 24% 85% 0% 158 1992
Williamson County 16% 74% 0% 29 1981
Winnebago County 9% 28% 0% 232 1971
Woodford County 49% 81% 0% 23 1972

How these shares are counted

Shares are of mapped land in USDA's soil survey (SSURGO), weighted by each soil's share of every map unit. Drought is the US Drought Monitor's D1-or-worse share on the September 22, 2026 map. Flood losses are FEMA NFIP records since 2016. Sources and methods.