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Alaska soil by county

Across Alaska's mapped land, shrink-swell clay limits houses without basements on under 1% and a shallow water table limits basements on 51%.

Highest clay shares: Copper River Census Area (3%), Aleutians East Borough (0%), Anchorage Municipality (0%), Bristol Bay Borough (0%), Chugach Census Area (0%). Highest water-table shares: North Slope Borough (67%), Northwest Arctic Borough (64%), Nome Census Area (63%), Yukon-Koyukuk Census Area (62%), Southeast Fairbanks Census Area (62%).

Data as of September 22, 2026 · 30 boroughs and census areas

Aleutians East Borough: 0%Aleutians West Census Area: no dataAnchorage Municipality: 0%Bethel Census Area: no dataBristol Bay Borough: 0%Chugach Census Area: 0%Copper River Census Area: 3%Denali Borough: no dataDillingham Census Area: 0%Fairbanks North Star Borough: 0%Haines Borough: 0%Hoonah-Angoon Census Area: 0%Juneau City and Borough: 0%Kenai Peninsula Borough: 0%Ketchikan Gateway Borough: 0%Kodiak Island Borough: 0%Kusilvak Census Area: no dataLake and Peninsula Borough: no dataMatanuska-Susitna Borough: no dataNome Census Area: 0%North Slope Borough: 0%Northwest Arctic Borough: 0%Petersburg Borough: no dataPrince of Wales-Hyder Census Area: 0%Sitka City and Borough: no dataSkagway Municipality: 0%Southeast Fairbanks Census Area: 0%Wrangell City and Borough: 0%Yakutat City and Borough: 0%Yukon-Koyukuk Census Area: 0%
Expansive clay: share of mapped land where shrink-swell clay limits houses without basementsunder 10%10-25%25-40%40-60%60%+
Aleutians East Borough: 11%Aleutians West Census Area: no dataAnchorage Municipality: 28%Bethel Census Area: no dataBristol Bay Borough: 34%Chugach Census Area: 29%Copper River Census Area: 37%Denali Borough: no dataDillingham Census Area: 61%Fairbanks North Star Borough: 56%Haines Borough: 25%Hoonah-Angoon Census Area: 21%Juneau City and Borough: 10%Kenai Peninsula Borough: 39%Ketchikan Gateway Borough: 47%Kodiak Island Borough: 27%Kusilvak Census Area: no dataLake and Peninsula Borough: no dataMatanuska-Susitna Borough: no dataNome Census Area: 63%North Slope Borough: 67%Northwest Arctic Borough: 64%Petersburg Borough: no dataPrince of Wales-Hyder Census Area: 35%Sitka City and Borough: no dataSkagway Municipality: 27%Southeast Fairbanks Census Area: 62%Wrangell City and Borough: 37%Yakutat City and Borough: 23%Yukon-Koyukuk Census Area: 62%
High water table: share of mapped land where a shallow water table limits basementsunder 10%10-25%25-40%40-60%60%+

Every boroughs and census area in Alaska

Select a column heading to sort.
Aleutians East Borough 0% 11% 0% 0 1981
Aleutians West Census Area n/a n/a 0% 0 1990
Anchorage Municipality 0% 28% 0% 13 1982
Bethel Census Area n/a n/a 0% 4 1988
Bristol Bay Borough 0% 34% 0% 0 1985
Chugach Census Area 0% 29% 0% 0 1979
Copper River Census Area 3% 37% 0% 0 1985
Denali Borough n/a n/a 0% 0 1989
Dillingham Census Area 0% 61% 0% 0 1985
Fairbanks North Star Borough 0% 56% 0% 31 1985
Haines Borough 0% 25% 0% 0 1987
Hoonah-Angoon Census Area 0% 21% 0% 0 1984
Juneau City and Borough 0% 10% 0% 74 1982
Kenai Peninsula Borough 0% 39% 0% 10 1990
Ketchikan Gateway Borough 0% 47% 3% 3 1977
Kodiak Island Borough 0% 27% 0% 0 1987
Kusilvak Census Area n/a n/a 0% 0 1989
Lake and Peninsula Borough n/a n/a 0% 0 1986
Matanuska-Susitna Borough n/a n/a 0% 10 1997
Nome Census Area 0% 63% 0% 10 1985
North Slope Borough 0% 67% 0% 0 1984
Northwest Arctic Borough 0% 64% 0% 9 1987
Petersburg Borough n/a n/a 0% 0 1979
Prince of Wales-Hyder Census Area 0% 35% 67% 0 1987
Sitka City and Borough n/a n/a 0% 1 1980
Skagway Municipality 0% 27% 0% 0 1985
Southeast Fairbanks Census Area 0% 62% 0% 0 1988
Wrangell City and Borough 0% 37% 8% 0 1976
Yakutat City and Borough 0% 23% 0% 0 1982
Yukon-Koyukuk Census Area 0% 62% 0% 1 1984

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.