Dane County, Wisconsin
A shallow water table limits basements on 34% of Dane County's mapped land, a higher share than 52% of US counties. Shrink-swell clay limits houses without basements on 7%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 121 flood losses here since 2016, 63% of them in buildings with basements. 43% of homes were built before 1980, against 50% nationally; the median home dates from 1986.
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 Dane County
| Expansive clay (limits slab homes) | 6.8% |
| High water table (limits basements) | 33.9% |
| Septic fields very limited | 85.8% |
| Clay swell (LEP, by area) | 4.1% |
| High-swell land (LEP 6%+) | 11.2% |
| Mapped soil | 793,094 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Plano | 7% | n/a |
| Dodge | 6% | n/a |
| St. Charles | 5% | n/a |
| McHenry | 5% | n/a |
| Kidder | 4% | n/a |
| Ringwood | 4% | n/a |
How we count · survey areas WI025 (2025-09-10)
What the numbers mean here
On 34% of Dane 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: 30.77 in, 6.57 in below the 1991-2020 average year of 37.34 in.
USDA rates 86% 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 32 of the last 52 weeks; the most was 67.4% of its area, on the July 28, 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
121 flood losses since 2016, $6.1 million paid. The worst year was 2018, with 85. Foundations of the buildings, where recorded: 63% basements, 17% slabs, 2% crawl spaces, 19% elevated. Median water depth outside the building: 15 in.
| Year | Flood losses |
|---|---|
| 2016 | 6 |
| 2017 | 5 |
| 2018 | 85 |
| 2019 | 12 |
| 2020 | 3 |
| 2021 | 0 |
| 2022 | 3 |
| 2023 | 2 |
| 2024 | 5 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 37.34 in |
| 12 months to August 2026 | 30.77 in (-6.57) |
| 2025 | 32.24 in (-5.10) |
| Wettest year since 1895 | 2018: 53.58 in |
| Driest year since 1895 | 1901: 20.96 in |
| Days with 1 inch or more, normal at UW ARBORETUM - MADISON (2 mi away) | 9.3 |
Homes
| Housing units | 261,061 |
| Median year built | 1986 |
| Built before 1980 | 43% |
| Built 2000 or later | 33% |
| Owner-occupied | 57% |
| Median value, owner-occupied | $394,800 |
| Single-family detached | 51% |
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 |
|---|---|---|---|
| Columbia County, WI | 28 mi | 1% | 48% |
| Green County, WI | 29 mi | 30% | 19% |
| Rock County, WI | 32 mi | 5% | 31% |
| Jefferson County, WI | 33 mi | 4% | 57% |
| Sauk County, WI | 36 mi | 1% | 26% |
| Iowa County, WI | 36 mi | 37% | 12% |
| Dodge County, WI | 44 mi | 7% | 59% |
| Lafayette County, WI | 46 mi | 29% | 14% |
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