Wisconsin: basement moisture and foundation risk by county
72 counties, ranked by our combined index. Highest combined risk is Fond du Lac County (59), lowest is Menominee County (20). The worst soil for foundation cracks specifically is in Rock County.
| County | Index | Moisture | Cracks | Water table | Region |
|---|---|---|---|---|---|
| Fond du Lac County | 59 | 52 | 52 | 82 | Wisconsinan till plain |
| Kenosha County | 59 | 56 | 48 | 82 | Wisconsinan till plain |
| Ozaukee County | 59 | 52 | 52 | 82 | Wisconsinan till plain |
| Green Lake County | 58 | 56 | 42 | 82 | Wisconsinan till plain |
| Calumet County | 57 | 56 | 52 | 66 | Wisconsinan till plain |
| Rock County | 57 | 54 | 54 | 66 | Wisconsinan till plain |
| Sheboygan County | 57 | 55 | 52 | 66 | Wisconsinan till plain |
| Racine County | 56 | 56 | 48 | 66 | Wisconsinan till plain |
| Washington County | 56 | 55 | 38 | 82 | Wisconsinan till plain |
| Columbia County | 55 | 54 | 38 | 82 | Wisconsinan till plain |
| Walworth County | 55 | 54 | 36 | 82 | Wisconsinan till plain |
| Milwaukee County | 54 | 52 | 49 | 66 | Wisconsinan till plain |
| Waukesha County | 54 | 52 | 48 | 66 | Wisconsinan till plain |
| Waushara County | 52 | 55 | 53 | 46 | Wisconsinan till plain |
| Winnebago County | 52 | 56 | 52 | 46 | Wisconsinan till plain |
| Manitowoc County | 50 | 54 | 33 | 66 | Wisconsinan till plain |
| Dane County | 49 | 52 | 33 | 66 | Wisconsinan till plain |
| Dodge County | 49 | 52 | 48 | 46 | Wisconsinan till plain |
| Green County | 48 | 56 | 39 | 46 | Wisconsinan till plain |
| Outagamie County | 47 | 53 | 39 | 46 | Wisconsinan till plain |
| Jefferson County | 46 | 57 | 30 | 46 | Wisconsinan till plain |
| Wood County | 40 | 39 | 22 | 66 | Central Wisconsin Sand Plain |
| Portage County | 38 | 39 | 16 | 66 | Central Wisconsin Sand Plain |
| Buffalo County | 35 | 37 | 35 | 30 | Driftless Area |
| Richland County | 35 | 37 | 37 | 30 | Driftless Area |
| Adams County | 34 | 40 | 16 | 46 | Central Wisconsin Sand Plain |
| La Crosse County | 34 | 33 | 26 | 46 | Driftless Area |
| Marquette County | 34 | 42 | 15 | 46 | Central Wisconsin Sand Plain |
| Juneau County | 33 | 40 | 14 | 46 | Central Wisconsin Sand Plain |
| Crawford County | 32 | 37 | 25 | 30 | Driftless Area |
| Barron County | 31 | 31 | 19 | 46 | Glaciofluvial sand plains |
| Oconto County | 31 | 33 | 16 | 46 | Glaciofluvial sand plains |
| Polk County | 31 | 31 | 20 | 46 | Glaciofluvial sand plains |
| Sauk County | 30 | 35 | 22 | 30 | Driftless Area |
| Vernon County | 30 | 34 | 35 | 16 | Driftless Area |
| Lafayette County | 29 | 34 | 22 | 30 | Driftless Area |
| Marathon County | 29 | 33 | 10 | 46 | Glaciofluvial sand plains |
| Oneida County | 29 | 32 | 13 | 46 | Glaciofluvial sand plains |
| Sawyer County | 29 | 30 | 16 | 46 | Glaciofluvial sand plains |
| Brown County | 28 | 32 | 11 | 46 | Glaciofluvial sand plains |
| Grant County | 28 | 36 | 25 | 16 | Driftless Area |
| Iowa County | 28 | 33 | 30 | 16 | Driftless Area |
| Pierce County | 28 | 31 | 12 | 46 | Glaciofluvial sand plains |
| Price County | 28 | 33 | 20 | 30 | Glaciofluvial sand plains |
| Burnett County | 27 | 30 | 20 | 30 | Glaciofluvial sand plains |
| Door County | 27 | 31 | 20 | 30 | Glaciofluvial sand plains |
| Eau Claire County | 27 | 32 | 19 | 30 | Glaciofluvial sand plains |
| Jackson County | 27 | 33 | 27 | 16 | Driftless Area |
| Monroe County | 27 | 37 | 21 | 16 | Driftless Area |
| Pepin County | 27 | 36 | 23 | 16 | Driftless Area |
| Dunn County | 26 | 31 | 15 | 30 | Glaciofluvial sand plains |
| Langlade County | 26 | 30 | 17 | 30 | Glaciofluvial sand plains |
| Shawano County | 26 | 29 | 19 | 30 | Glaciofluvial sand plains |
| Waupaca County | 26 | 30 | 7 | 46 | Glaciofluvial sand plains |
| Ashland County | 25 | 33 | 9 | 30 | Glaciofluvial sand plains |
| Chippewa County | 25 | 33 | 9 | 30 | Glaciofluvial sand plains |
| Forest County | 25 | 33 | 9 | 30 | Glaciofluvial sand plains |
| Marinette County | 25 | 32 | 13 | 30 | Glaciofluvial sand plains |
| Vilas County | 25 | 31 | 14 | 30 | Glaciofluvial sand plains |
| Bayfield County | 24 | 30 | 11 | 30 | Glaciofluvial sand plains |
| Iron County | 24 | 30 | 11 | 30 | Glaciofluvial sand plains |
| Kewaunee County | 24 | 32 | 7 | 30 | Glaciofluvial sand plains |
| Trempealeau County | 24 | 33 | 16 | 16 | Driftless Area |
| Washburn County | 24 | 29 | 12 | 30 | Glaciofluvial sand plains |
| Clark County | 23 | 30 | 17 | 16 | Glaciofluvial sand plains |
| Douglas County | 23 | 31 | 16 | 16 | Glaciofluvial sand plains |
| Florence County | 22 | 30 | 16 | 16 | Glaciofluvial sand plains |
| Lincoln County | 22 | 33 | 11 | 16 | Glaciofluvial sand plains |
| Rusk County | 22 | 29 | 16 | 16 | Glaciofluvial sand plains |
| St. Croix County | 21 | 33 | 7 | 16 | Glaciofluvial sand plains |
| Taylor County | 21 | 29 | 13 | 16 | Glaciofluvial sand plains |
| Menominee County | 20 | 29 | 10 | 16 | Glaciofluvial sand plains |
Values from USDA NRCS SSURGO where available, otherwise our regional model — each county page states which. Methodology.
The physiographic regions inside Wisconsin
State lines are political; soil follows geology. These are the distinct ground types inside Wisconsin and why each behaves the way it does.
Glaciofluvial sand plains
Sand sheds water and there is very little clay, so volume-change cracking is rare. Where the outwash is thin over till or bedrock, though, a local perched water table forms and basements leak even in sand.
33 counties: Ashland County, Barron County, Bayfield County, Brown County, Burnett County, Chippewa County, Clark County, Door County, Douglas County, Dunn County, Eau Claire County, Florence County, Forest County, Iron County, Kewaunee County, Langlade County, Lincoln County, Marathon County, Marinette County, Menominee County, Oconto County, Oneida County, Pierce County, Polk County, Price County, Rusk County, Sawyer County, Shawano County, St. Croix County, Taylor County, Vilas County, Washburn County, Waupaca County
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.
21 counties: Calumet County, Columbia County, Dane County, Dodge County, Fond du Lac County, Green County, Green Lake County, Jefferson County, Kenosha County, Manitowoc County, Milwaukee County, Outagamie County, Ozaukee County, Racine County, Rock County, Sheboygan County, Walworth County, Washington County, Waukesha County, Waushara County, Winnebago 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.
13 counties: Buffalo County, Crawford County, Grant County, Iowa County, Jackson County, La Crosse County, Lafayette County, Monroe County, Pepin County, Richland County, Sauk County, Trempealeau County, Vernon County
Central Wisconsin Sand Plain
Sand, but flat sand with the water table close behind it. Cracking is not the issue; a pump that runs through spring is. Easy to mistake for the well-drained sand country further north.
5 counties: Adams County, Juneau County, Marquette County, Portage County, Wood County
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