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Lee County, Illinois

A shallow water table limits basements on 66% of Lee County's mapped land, a higher share than 79% of US counties. Shrink-swell clay limits houses without basements on 14%.

None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 2 flood losses here since 2016. 72% of homes were built before 1980, against 50% nationally; the median home dates from 1960.

Data as of October 13, 2026 · sources

14%

expansive clay: shrink-swell limits slab homes

66%

high water table: limits basements

0%

in drought, October 13, 2026

72%

of homes built before 1980

Soil under Lee County

Expansive clay (limits slab homes)14.4%
High water table (limits basements)65.9%
Septic fields very limited83.9%
Clay swell (LEP, by area)4.0%
High-swell land (LEP 6%+)2.9%
Mapped soil466,500 acres
Soil seriesShare hereSeries nationally: high water table
Catlin7%n/a
Osco7%3%
Wyanet6%n/a
Drummer5%over 99%
Muscatune4%n/a
Saybrook4%n/a
Ogle County: 35%Bureau County: 53%DeKalb County: 98%Whiteside County: 40%LaSalle County: 84%Putnam County: 50%Carroll County: 17%Winnebago County: 28%Lee County OgleBureauDeKalbWhitesideLaSallePutnamCarrollWinnebagoLee
Lee County (heavy outline) and nearby counties, shaded by high water table share.under 10%10-25%25-40%40-60%60%+

How we count · survey areas IL103 (2025-08-31)

What the numbers mean here

On 66% of Lee 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: 37.43 in, 0.81 in below the 1991-2020 average year of 38.24 in.

USDA rates 84% 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 19 of the last 52 weeks; the most was 100% of its area, in 8 weeks, most recently on the June 9, 2026 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026
Category, October 13, 2026Share of county
D0 abnormally dry or worse0%
D1 moderate drought or worse0%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

2 flood losses since 2016, $0 paid. The worst year was 2019, with 1.

YearFlood losses
20161
20170
20180
20191
20200
20210
20220
20230
20240
20250
2026 to date0

Rain

Average year, 1991-202038.24 in
12 months to August 202637.43 in (-0.81)
202533.09 in (-5.15)
Wettest year since 18952019: 52.35 in
Driest year since 18951910: 23.30 in
Days with 1 inch or more, normal at DIXON 1W (13 mi away)10.3

Homes

Housing units14,995
Median year built1960
Built before 198072%
Built 2000 or later12%
Owner-occupied74%
Median value, owner-occupied$154,600
Single-family detached79%

What repairs cost

Published ranges from cost guides, not quotes. More sources, and where they disagree.

WorkRangeSource
Basement waterproofing, US $3,000 to $10,000 Fixr, February 6, 2026
Sump pump installation, US $800 to $2,000 Fixr, January 31, 2025
Crawl space encapsulation, US $2,000 to $8,000 Fixr, August 29, 2025

Nearby counties

PlaceDistanceExpansive clayHigh water table
Ogle County, IL 20 mi 10% 35%
Bureau County, IL 27 mi 25% 53%
DeKalb County, IL 29 mi 28% 98%
Whiteside County, IL 32 mi 2% 40%
LaSalle County, IL 35 mi 37% 84%
Putnam County, IL 38 mi 23% 50%
Carroll County, IL 39 mi 13% 17%
Winnebago County, IL 41 mi 9% 28%

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