Tazewell County, Illinois
A shallow water table limits basements on 53% of Tazewell County's mapped land, a higher share than 69% of US counties. Shrink-swell clay limits houses without basements on 33%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 16 flood losses here since 2016. 72% 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 Tazewell County
| Expansive clay (limits slab homes) | 32.7% |
| High water table (limits basements) | 53.2% |
| Septic fields very limited | 76.8% |
| Clay swell (LEP, by area) | 4.3% |
| High-swell land (LEP 6%+) | 16.9% |
| Mapped soil | 420,910 acres |
How we count · survey areas IL179 (2025-08-31)
What the numbers mean here
Clay swell averages a linear extensibility of 4.3% by land area here, and 17% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 33% of the mapped land.
On 53% of Tazewell 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: 39.80 in, 1.33 in above the 1991-2020 average year of 38.47 in.
USDA rates 77% 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 24 of the last 52 weeks; the most was 100% of its area, in 24 weeks, most recently on the March 31, 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
16 flood losses since 2016, $329,638 paid. The worst year was 2020, with 5.
| Year | Flood losses |
|---|---|
| 2016 | 4 |
| 2017 | 0 |
| 2018 | 1 |
| 2019 | 3 |
| 2020 | 5 |
| 2021 | 2 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 38.47 in |
| 12 months to August 2026 | 39.80 in (+1.33) |
| 2025 | 27.16 in (-11.31) |
| Wettest year since 1895 | 1993: 57.40 in |
| Driest year since 1895 | 1988: 22.37 in |
| Days with 1 inch or more, normal at PEORIA GTR PEORIA AP (14 mi away) | 9.2 |
Homes
| Housing units | 58,731 |
| Median year built | 1969 |
| Built before 1980 | 72% |
| Built 2000 or later | 15% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $167,500 |
| 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 |
|---|---|---|---|
| Peoria County, IL | 23 mi | 29% | 37% |
| Woodford County, IL | 25 mi | 49% | 81% |
| Logan County, IL | 27 mi | 45% | 71% |
| Mason County, IL | 28 mi | 3% | 42% |
| McLean County, IL | 35 mi | 54% | 85% |
| Fulton County, IL | 36 mi | 24% | 38% |
| Menard County, IL | 37 mi | 27% | 51% |
| Marshall County, IL | 37 mi | 36% | 66% |
Sources: USDA SSURGO (August 31, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status