St. Louis County, Minnesota
A shallow water table limits basements on 70% of St. Louis County's mapped land, a higher share than 81% of US counties. Shrink-swell clay limits houses without basements on 10%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 15 flood losses here since 2016. 70% 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 St. Louis County
| Expansive clay (limits slab homes) | 10.3% |
| High water table (limits basements) | 69.7% |
| Septic fields very limited | 88.1% |
| Clay swell (LEP, by area) | 2.4% |
| High-swell land (LEP 6%+) | 13.6% |
| Mapped soil | 4,331,918 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Greenwood | 10% | n/a |
| Rifle | 7% | n/a |
| Conic | 3% | n/a |
| Eveleth | 3% | n/a |
| Tacoosh | 3% | n/a |
| Eaglesnest | 3% | n/a |
How we count · survey areas MN613 (2025-09-10), MN615 (2025-09-10), MN617 (2025-09-10), MN619 (2025-09-10), MN621 (2025-09-10), MN627 (2025-09-10)
What the numbers mean here
On 70% of St. Louis 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: 24.10 in, 4.23 in below the 1991-2020 average year of 28.33 in.
USDA rates 88% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 46 of the last 52 weeks; the most was 100% of its area, in 26 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 35.1% |
| D3 extreme or worse | 0.6% |
| D4 exceptional | 0% |
Flood losses since 2016
15 flood losses since 2016, $549,357 paid. The worst year was 2024, with 6.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 2 |
| 2019 | 3 |
| 2020 | 1 |
| 2021 | 0 |
| 2022 | 3 |
| 2023 | 0 |
| 2024 | 6 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 28.33 in |
| 12 months to August 2026 | 24.10 in (-4.23) |
| 2025 | 25.98 in (-2.35) |
| Wettest year since 1895 | 1977: 35.90 in |
| Driest year since 1895 | 1910: 18.12 in |
| Days with 1 inch or more, normal at EVELETH WWTP (8 mi away) | 4.6 |
Homes
| Housing units | 104,263 |
| Median year built | 1962 |
| Built before 1980 | 70% |
| Built 2000 or later | 15% |
| Owner-occupied | 71% |
| Median value, owner-occupied | $221,400 |
| Single-family detached | 73% |
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 |
|---|---|---|---|
| Itasca County, MN | 52 mi | 8% | 54% |
| Lake County, MN | 52 mi | 5% | 57% |
| Carlton County, MN | 68 mi | 6% | 53% |
| Koochiching County, MN | 75 mi | 16% | 90% |
| Aitkin County, MN | 80 mi | 1% | 74% |
| Douglas County, WI | 82 mi | 20% | 56% |
| Bayfield County, WI | 91 mi | 20% | 46% |
| Cass County, MN | 96 mi | 1% | 44% |
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