Wisconsin / Outagamie County
Score 44 · elevated · #14 of 72 in WI
Crawl space moisture in Outagamie County, WI
60% of Outagamie County's soil falls in hydrologic group D or a dual D group: clays and high water tables that shed water slowly. Where a seasonal water table is reported — 72% of acres — it averages 1.6 ft below grade, shallow enough to reach a typical crawl-space footing.
- 1Water table 1.6 ft
- 2Wet soils 48%
- 3Moisture score 44
- 4EPA radon zone 2
Reading the Outagamie County soil survey
The score of 44 combines four parts, each from the USDA survey: wet drainage classes contribute 41.1 points of 100 on their own scale, group D soils 48.8, a shallow water table 54, and flooding 21.8; the weights are on the methodology page. The dominant hydrologic group is C (28% of acres): slow infiltration (clay layers).
A water table under two feet is the single most important number here. A crawl-space floor is usually 18 to 36 inches below the joists and often below outside grade, so in a wet season groundwater can stand at or above the crawl-space floor across much of Outagamie County. Venting cannot fix that; it needs drainage — a perimeter drain to daylight or a sump — before any liner goes down.
Outagamie County against the rest of Wisconsin
Outagamie County ranks 14 of 72 Wisconsin counties, 11 points above the state median of 33. That puts it in the wettest quarter of the state. Statewide, 32% of mapped soil is in the wet drainage classes; here it is 48%. After well drained, the next most common class is somewhat poorly drained at 26%.
Flooding. 15.9% of acres with a flooding class are rated frequent; 9.9% of acres with a flooding class are rated occasional. That is a large flood-prone share; a crawl space in the floodplain needs flood vents under most local floodplain ordinances, which is a separate rule from R408 and can rule out a fully sealed design.
What it means for a crawl space here
In an elevated county the soil supplies more moisture than average, but a vented crawl space can work if the ground is covered: the code lets vent area drop from 1 sq ft per 150 to 1 per 1500 with a Class I vapor retarder on the ground, which is an admission of how much moisture comes from below. Grading, gutters and a ground cover usually decide whether a crawl space here stays dry before any decision about sealing it.
Radon. EPA radon zone 2. The zone is a county-level prediction; EPA says elevated levels occur in every zone and every home should be tested.
Near Outagamie County by score
Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area WI087; drainage covers 99% of 412,659 mapped acres); EPA Map of Radon Zones, county table (June 2024 JSON); IRC R408.3 Unvented crawl space, as adopted in S.C. Code Regs. 8-1221 (LII). Checked 2026-10-23.