Wisconsin / Sawyer County
Score 40 · elevated · #20 of 72 in WI
Crawl space moisture in Sawyer County, WI
53% of Sawyer 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 — 64% of acres — it averages 0.8 ft below grade, shallow enough to reach a typical crawl-space footing.
- 1Water table 0.8 ft
- 2Wet soils 35%
- 3Moisture score 40
- 4EPA radon zone 2
Reading the Sawyer County soil survey
The score of 40 combines four parts, each from the USDA survey: wet drainage classes contribute 41.3 points of 100 on their own scale, group D soils 36.6, a shallow water table 56.3, and flooding 2.4; the weights are on the methodology page. The dominant hydrologic group is C/D (32% of acres): D when undrained, C when drained.
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 Sawyer County. Venting cannot fix that; it needs drainage — a perimeter drain to daylight or a sump — before any liner goes down.
Sawyer County against the rest of Wisconsin
Sawyer County ranks 20 of 72 Wisconsin counties, 7 points above the state median of 33. Wetter counties exist in Wisconsin, but the soil here still sits well above the national middle. Statewide, 32% of mapped soil is in the wet drainage classes; here it is 35%. After moderately well drained, the next most common class is well drained at 20%.
Flooding. 2.1% of acres with a flooding class are rated frequent; 0.5% of acres with a flooding class are rated occasional. Flood-prone soils are a minority here, concentrated along streams; the score mostly reflects what happens between floods. Ponding — water standing at the surface with nowhere to go — affects 2.8% of acres.
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 Sawyer County by score
Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area WI113; drainage covers 93% of 863,846 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.