Brown County, Wisconsin
Shrink-swell clay limits houses without basements on 47% of Brown County's mapped land, a higher share than 90% of US counties and the highest of 72 Wisconsin counties. A shallow water table limits basements on 32%.
21.2% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 131 flood losses here since 2016, 65% of them in buildings with basements. 48% of homes were built before 1980, against 50% nationally; the median home dates from 1981.
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 Brown County
| Expansive clay (limits slab homes) | 46.7% |
| High water table (limits basements) | 32.0% |
| Septic fields very limited | 75.9% |
| Clay swell (LEP, by area) | 5.0% |
| High-swell land (LEP 6%+) | 46.0% |
| Mapped soil | 349,050 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Kewaunee | 23% | n/a |
| Manawa | 11% | n/a |
| Oshkosh | 10% | n/a |
| Waymor | 5% | n/a |
| Poygan | 3% | n/a |
| Shawano | 3% | n/a |
How we count · survey areas WI009 (2025-09-10)
What the numbers mean here
Clay swell averages a linear extensibility of 5.0% by land area here, and 46% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 47% of the mapped land.
Clay shrinks as it dries: 21.2% of the county is in drought on the latest map, and 47% of Brown County's mapped land has shrink-swell clay.
On 32% of Brown 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: 32.46 in, 0.30 in below the 1991-2020 average year of 32.76 in.
USDA rates 76% of the land very limited for septic absorption fields.
Drought
21.2% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 31 of the last 52 weeks; the most was 100% of its area, in 16 weeks, most recently on the February 17, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 34.5% |
| D1 moderate drought or worse | 21.2% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
131 flood losses since 2016, $1.6 million paid. The worst year was 2019, with 74. Foundations of the buildings, where recorded: 65% basements, 32% slabs, 3% crawl spaces. Median water depth outside the building: 12 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 12 |
| 2019 | 74 |
| 2020 | 20 |
| 2021 | 3 |
| 2022 | 4 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 17 |
Rain
| Average year, 1991-2020 | 32.76 in |
| 12 months to August 2026 | 32.46 in (-0.30) |
| 2025 | 28.43 in (-4.33) |
| Wettest year since 1895 | 2019: 47.80 in |
| Driest year since 1895 | 1895: 18.70 in |
| Days with 1 inch or more, normal at GREEN BAY (6 mi away) | 5.9 |
Homes
| Housing units | 115,493 |
| Median year built | 1981 |
| Built before 1980 | 48% |
| Built 2000 or later | 25% |
| Owner-occupied | 66% |
| Median value, owner-occupied | $266,000 |
| Single-family detached | 64% |
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 |
|---|---|---|---|
| Outagamie County, WI | 23 mi | 20% | 54% |
| Kewaunee County, WI | 28 mi | 19% | 40% |
| Calumet County, WI | 29 mi | 44% | 42% |
| Manitowoc County, WI | 30 mi | 38% | 47% |
| Oconto County, WI | 38 mi | 0% | 51% |
| Winnebago County, WI | 43 mi | 33% | 48% |
| Shawano County, WI | 43 mi | under 1% | 50% |
| Waupaca County, WI | 48 mi | 1% | 46% |
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