Milwaukee County, Wisconsin
A shallow water table limits basements on 57% of Milwaukee County's mapped land, a higher share than 72% of US counties. Shrink-swell clay limits houses without basements on 8%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 316 flood losses here since 2016, 92% of them in buildings with basements. 79% of homes were built before 1980, against 50% nationally; the median home dates from 1957.
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 Milwaukee County
| Expansive clay (limits slab homes) | 8.1% |
| High water table (limits basements) | 57.4% |
| Septic fields very limited | 60.3% |
| Clay swell (LEP, by area) | 4.2% |
| High-swell land (LEP 6%+) | 8.0% |
| Mapped soil | 155,424 acres |
How we count · survey areas WI079 (2025-09-10)
What the numbers mean here
On 57% of Milwaukee 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: 34.14 in, 0.32 in below the 1991-2020 average year of 34.46 in.
USDA rates 60% 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 5 of the last 52 weeks; the most was 100% of its area, in 3 weeks, most recently 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
316 flood losses since 2016, $12.2 million paid. The worst year was 2025, with 271. Foundations of the buildings, where recorded: 92% basements, 5% slabs, 1% crawl spaces, 2% elevated. Median water depth outside the building: 6 in.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 3 |
| 2018 | 4 |
| 2019 | 5 |
| 2020 | 8 |
| 2021 | 3 |
| 2022 | 6 |
| 2023 | 2 |
| 2024 | 0 |
| 2025 | 271 |
| 2026 to date | 12 |
Rain
| Average year, 1991-2020 | 34.46 in |
| 12 months to August 2026 | 34.14 in (-0.32) |
| 2025 | 35.87 in (+1.41) |
| Wettest year since 1895 | 2018: 44.00 in |
| Driest year since 1895 | 1963: 19.51 in |
| Days with 1 inch or more, normal at MILWAUKEE MITCHELL AP (4 mi away) | 6.8 |
Homes
| Housing units | 426,715 |
| Median year built | 1957 |
| Built before 1980 | 79% |
| Built 2000 or later | 10% |
| Owner-occupied | 50% |
| Median value, owner-occupied | $230,700 |
| Single-family detached | 45% |
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 |
|---|---|---|---|
| Racine County, WI | 10 mi | 15% | 76% |
| Kenosha County, WI | 22 mi | 15% | 76% |
| Waukesha County, WI | 23 mi | 3% | 42% |
| Washington County, WI | 38 mi | 1% | 44% |
| Walworth County, WI | 38 mi | under 1% | 33% |
| Ozaukee County, WI | 41 mi | 41% | 43% |
| Jefferson County, WI | 47 mi | 4% | 57% |
| Lake County, IL | 50 mi | 16% | 87% |
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