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Maryland soil by county

Across Maryland's mapped land, shrink-swell clay limits houses without basements on 1% and a shallow water table limits basements on 45%.

Highest clay shares: Washington County (9%), Harford County (5%), Baltimore city (5%), Charles County (4%), Allegany County (2%). Highest water-table shares: Caroline County (86%), Worcester County (86%), Wicomico County (84%), Queen Anne's County (79%), Dorchester County (69%).

Data as of September 22, 2026 · 24 counties

Allegany County: 2%Anne Arundel County: 0%Baltimore city: 5%Baltimore County: 2%Calvert County: 0%Caroline County: 0%Carroll County: 0%Cecil County: 2%Charles County: 4%Dorchester County: 0%Frederick County: 1%Garrett County: 0%Harford County: 5%Howard County: 1%Kent County: 0%Montgomery County: 1%Prince George's County: 1%Queen Anne's County: 0%Somerset County: 0%St. Mary's County: 1%Talbot County: 0%Washington County: 9%Wicomico County: 0%Worcester County: 0%
Expansive clay: share of mapped land where shrink-swell clay limits houses without basementsunder 10%10-25%25-40%40-60%60%+
Allegany County: 21%Anne Arundel County: 46%Baltimore city: 18%Baltimore County: 23%Calvert County: 56%Caroline County: 86%Carroll County: 21%Cecil County: 38%Charles County: 61%Dorchester County: 69%Frederick County: 22%Garrett County: 47%Harford County: 29%Howard County: 24%Kent County: 54%Montgomery County: 19%Prince George's County: 46%Queen Anne's County: 79%Somerset County: 40%St. Mary's County: 47%Talbot County: 65%Washington County: 18%Wicomico County: 84%Worcester County: 86%
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 Maryland

Select a column heading to sort.
Allegany County 2% 21% 0% 52 1959
Anne Arundel County 0% 46% 0% 322 1983
Baltimore County 2% 23% 13% 281 1973
Baltimore city 5% 18% 0% 194 1947
Calvert County under 1% 56% 0% 73 1990
Caroline County 0% 86% 87% 4 1981
Carroll County 0% 21% 98% 27 1983
Cecil County 2% 38% 0% 83 1987
Charles County 4% 61% 0% 79 1991
Dorchester County 0% 69% 66% 224 1975
Frederick County 1% 22% 100% 76 1991
Garrett County 0% 47% 0% 13 1982
Harford County 5% 29% 0% 52 1986
Howard County 1% 24% 8% 228 1989
Kent County 0% 54% 1% 17 1978
Montgomery County 1% 19% 5% 234 1980
Prince George's County 1% 46% 0% 439 1977
Queen Anne's County under 1% 79% 23% 99 1990
Somerset County under 1% 40% 0% 157 1986
St. Mary's County 1% 47% 0% 82 1992
Talbot County 0% 65% 30% 76 1983
Washington County 9% 18% 76% 21 1974
Wicomico County under 1% 84% 48% 85 1984
Worcester County 0% 86% 12% 78 1985

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.