Knox County, Indiana
A shallow water table limits basements on 46% of Knox County's mapped land, a higher share than 63% 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 9 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 Knox County
| Expansive clay (limits slab homes) | 8.2% |
| High water table (limits basements) | 46.0% |
| Septic fields very limited | 71.0% |
| Clay swell (LEP, by area) | 2.7% |
| High-swell land (LEP 6%+) | 3.6% |
| Mapped soil | 335,488 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Alford | 11% | n/a |
| Sylvan | 8% | n/a |
| Hosmer | 6% | over 99% |
| Selma | 5% | n/a |
| Wakeland | 5% | n/a |
| Haymond | 4% | n/a |
How we count · survey areas IN083 (2025-09-03)
What the numbers mean here
On 46% of Knox 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: 45.65 in, 1.17 in below the 1991-2020 average year of 46.82 in.
USDA rates 71% 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 6 of the last 52 weeks; the most was 80.2% of its area, in 2 weeks, most recently on the March 3, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
9 flood losses since 2016, $177,850 paid. The worst year was 2022, with 3.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 2 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 3 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 46.82 in |
| 12 months to August 2026 | 45.65 in (-1.17) |
| 2025 | 47.91 in (+1.09) |
| Wettest year since 1895 | 1945: 63.21 in |
| Driest year since 1895 | 1953: 29.05 in |
| Days with 1 inch or more, normal at VINCENNES 5 NE (5 mi away) | 12.6 |
Homes
| Housing units | 16,974 |
| Median year built | 1962 |
| Built before 1980 | 70% |
| Built 2000 or later | 11% |
| Owner-occupied | 68% |
| Median value, owner-occupied | $137,700 |
| Single-family detached | 75% |
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 |
|---|---|---|---|
| Lawrence County, IL | 17 mi | 23% | 78% |
| Daviess County, IN | 19 mi | 5% | 64% |
| Pike County, IN | 22 mi | 1% | 53% |
| Gibson County, IN | 27 mi | 4% | 62% |
| Sullivan County, IN | 28 mi | 2% | 61% |
| Wabash County, IL | 28 mi | 14% | 74% |
| Crawford County, IL | 28 mi | 43% | 81% |
| Martin County, IN | 33 mi | 3% | 30% |
Sources: USDA SSURGO (September 3, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status