Shiawassee County, Michigan
A shallow water table limits basements on 80% of Shiawassee County's mapped land, a higher share than 89% of US counties and the 10th highest of 83 Michigan counties. Shrink-swell clay limits houses without basements on 0%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 6 flood losses here since 2016. 70% of homes were built before 1980, against 50% nationally; the median home dates from 1969.
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 Shiawassee County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 80.0% |
| Septic fields very limited | 99.0% |
| Clay swell (LEP, by area) | 2.5% |
| High-swell land (LEP 6%+) | 0.0% |
| Mapped soil | 346,023 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Conover | 22% | n/a |
| Brookston | 16% | n/a |
| Wawasee | 6% | n/a |
| Boyer | 5% | n/a |
| Carlisle | 3% | n/a |
| Macomb | 3% | n/a |
How we count · survey areas MI155 (2025-09-04)
What the numbers mean here
On 80% of Shiawassee 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: 33.27 in, 0.61 in below the 1991-2020 average year of 33.88 in.
USDA rates 99% 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 8 of the last 52 weeks; the most was 33.5% of its area, in 7 weeks, most recently on the September 29, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 83.9% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
6 flood losses since 2016, $9,729 paid. The worst year was 2018, with 2.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 1 |
| 2018 | 2 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 33.88 in |
| 12 months to August 2026 | 33.27 in (-0.61) |
| 2025 | 31.38 in (-2.50) |
| Wettest year since 1895 | 2011: 46.17 in |
| Driest year since 1895 | 1934: 20.26 in |
| Days with 1 inch or more, normal at OWOSSO WWTP (5 mi away) | 5.8 |
Homes
| Housing units | 30,354 |
| Median year built | 1969 |
| Built before 1980 | 70% |
| Built 2000 or later | 12% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $171,600 |
| Single-family detached | 81% |
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 |
|---|---|---|---|
| Clinton County, MI | 22 mi | 0% | 80% |
| Genesee County, MI | 23 mi | under 1% | 72% |
| Saginaw County, MI | 26 mi | 6% | 95% |
| Ingham County, MI | 27 mi | 0% | 68% |
| Livingston County, MI | 27 mi | under 1% | 37% |
| Gratiot County, MI | 33 mi | 2% | 90% |
| Eaton County, MI | 43 mi | 0% | 76% |
| Oakland County, MI | 44 mi | 1% | 34% |
Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status