Crawl space moisture in Stark County, IL

Stark County scores moderate: no single wet-soil signal dominates its mapped acres. Where a seasonal water table is reported — 84% of acres — it averages 3 ft below grade.

Size venting or encapsulation

1Water table 3 ft
2Wet soils 39%
3Moisture score 32
4EPA radon zone 1

Share of mapped soil acres in Stark County, IL by NRCS drainage class (dominant condition), bars to scale; wetter classes highlighted. Covers 100% of mapped acres.

Dominant drainage

Well drained

50% of acres

Group D soils

40%

slow infiltration

Flood-prone acres

10%

any flooding frequency

Ponding

0.1%

acres where water ponds

Reading the Stark County soil survey

The score of 32 combines four parts, each from the USDA survey: wet drainage classes contribute 31.8 points of 100 on their own scale, group D soils 28, a shallow water table 45.7, and flooding 8.7; the weights are on the methodology page. The dominant hydrologic group is B (48% of acres): moderate infiltration.

Hydrologic soil groups in Stark County by share of acres, columns to scale. Group D and dual groups (x/D) shed water slowly and hold it near the surface.

At 3 ft the seasonal water table is usually below a crawl-space floor, but the 84% of acres that report one are by definition the wettest parts of the county; on those lots, a wet spring can bring water close to the footings.

Stark County against the rest of Illinois

Stark County ranks 84 of 102 Illinois counties, 17 points below the state median of 49. That places it in the middle range, nationally and for the state. Statewide, 57% of mapped soil is in the wet drainage classes; here it is 39%, below the state figure — the score here comes from a shallow water table rather than drainage class alone. After well drained, the next most common class is somewhat poorly drained at 33%.

Flooding. 6.6% of acres with a flooding class are rated frequent; 3.4% of acres with a flooding class are rated occasional; 0.2% of acres with a flooding class are rated rare. Flood-prone soils are a minority here, concentrated along streams; the score mostly reflects what happens between floods.

What it means for a crawl space here

In a moderate county the soil record is mixed rather than uniformly wet, so conditions vary from lot to lot. Where the lot drains, the model-code default — a vented crawl space with 1 sq ft of net vent per 150 sq ft of floor, or 1 per 1500 with a Class I vapor retarder on the ground — is a reasonable starting point; where the sections above point to a shallow water table or flood-prone soil on your lot, plan as for an elevated county. Either way, check the site first: grading that falls away from the foundation, gutters and downspouts that discharge well clear of it, and a ground cover over bare earth. A wet crawl space in a moderate county points to one of those first.

Radon. Stark County is in EPA radon zone 1, the highest predicted potential. A sealed crawl space and a radon system share most of their parts — the liner, the sealed seams, a fan — so if you are encapsulating, test for radon first and design both together. EPA itself says the zone map is not a reason to skip testing in zones 2 and 3.

Near Stark County by score

Mason County 32 Schuyler County 32 Cass County 33 Henry County 33

All 102 Illinois counties

Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area IL175; drainage covers 100% of 184,115 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.