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Fond du Lac County, Wisconsin
A shallow water table limits basements on 50% of Fond du Lac County's mapped land, a higher share than 66% of US counties. Shrink-swell clay limits houses without basements on 13%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 129 flood losses here since 2016, 87% of them in buildings with basements. 62% of homes were built before 1980, against 50% nationally; the median home dates from 1971.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Fond du Lac County
| Expansive clay (limits slab homes) | 13.3% |
| High water table (limits basements) | 50.2% |
| Septic fields very limited | 68.6% |
| Clay swell (LEP, by area) | 4.3% |
| High-swell land (LEP 6%+) | 11.6% |
| Mapped soil | 489,497 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Lomira | 10% | n/a |
| Pella | 9% | n/a |
| Theresa | 8% | n/a |
| Houghton | 5% | n/a |
| Kewaunee | 5% | n/a |
| Hochheim | 4% | n/a |
How we count · survey areas WI039 (2025-09-10)
What the numbers mean here
On 50% of Fond du Lac County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 29.81 in, 3.31 in below the 1991-2020 average year of 33.12 in.
USDA rates 69% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 21 of the last 52 weeks; the most was 87.3% of its area, in 4 weeks, most recently on the September 1, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
129 flood losses since 2016, $2.4 million paid. The worst year was 2019, with 110. Foundations of the buildings, where recorded: 87% basements, 7% slabs, 6% crawl spaces. Median water depth outside the building: 17 in.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 2 |
| 2018 | 5 |
| 2019 | 110 |
| 2020 | 4 |
| 2021 | 2 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 4 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 33.12 in |
| 12 months to August 2026 | 29.81 in (-3.31) |
| 2025 | 28.68 in (-4.44) |
| Wettest year since 1895 | 2019: 43.70 in |
| Driest year since 1895 | 1895: 19.02 in |
| Days with 1 inch or more, normal at FOND DU LAC WWTP (3 mi away) | 6.2 |
Homes
| Housing units | 46,094 |
| Median year built | 1971 |
| Built before 1980 | 62% |
| Built 2000 or later | 19% |
| Owner-occupied | 71% |
| Median value, owner-occupied | $222,800 |
| Single-family detached | 70% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Green Lake County, WI | 24 mi | 2% | 48% |
| Winnebago County, WI | 24 mi | 33% | 48% |
| Dodge County, WI | 25 mi | 7% | 59% |
| Calumet County, WI | 26 mi | 44% | 42% |
| Washington County, WI | 28 mi | 1% | 44% |
| Ozaukee County, WI | 37 mi | 41% | 43% |
| Sheboygan County, WI | 38 mi | 33% | 37% |
| Waushara County, WI | 45 mi | 5% | 36% |
Sources: USDA SSURGO (September 10, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status