Watonwan County, Minnesota
A shallow water table limits basements on 87% of Watonwan County's mapped land, a higher share than 94% of US counties. Shrink-swell clay limits houses without basements on 12%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 12 flood losses here since 2016. 72% of homes were built before 1980, against 50% nationally; the median home dates from 1962.
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 Watonwan County
| Expansive clay (limits slab homes) | 12.2% |
| High water table (limits basements) | 87.2% |
| Septic fields very limited | 92.7% |
| Clay swell (LEP, by area) | 3.8% |
| High-swell land (LEP 6%+) | 7.6% |
| Mapped soil | 281,300 acres |
How we count · survey areas MN165 (2025-09-10)
What the numbers mean here
On 87% of Watonwan 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: 22.26 in, 9.94 in below the 1991-2020 average year of 32.20 in.
USDA rates 93% 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 18 of the last 52 weeks; the most was 56.7% of its area, on the July 28, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 22.3% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
12 flood losses since 2016, $988,001 paid. The worst year was 2024, with 7.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 2 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 3 |
| 2024 | 7 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 32.20 in |
| 12 months to August 2026 | 22.26 in (-9.94) |
| 2025 | 28.13 in (-4.07) |
| Wettest year since 1895 | 2016: 48.36 in |
| Driest year since 1895 | 1910: 16.13 in |
| Days with 1 inch or more, normal at AMBOY (23 mi away) | 8.3 |
Homes
| Housing units | 4,881 |
| Median year built | 1962 |
| Built before 1980 | 72% |
| Built 2000 or later | 11% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $162,400 |
| Single-family detached | 83% |
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 |
|---|---|---|---|
| Brown County, MN | 19 mi | 10% | 85% |
| Martin County, MN | 21 mi | 9% | 87% |
| Blue Earth County, MN | 28 mi | 40% | 84% |
| Cottonwood County, MN | 28 mi | 8% | 86% |
| Nicollet County, MN | 32 mi | 10% | 83% |
| Jackson County, MN | 34 mi | 25% | 85% |
| Faribault County, MN | 39 mi | 37% | 88% |
| Emmet County, IA | 42 mi | 10% | 84% |
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