Delaware / Kent County
Score 43 · elevated · #1 of 3 in DE
Crawl space moisture in Kent County, DE
50% of Kent County's mapped soil is somewhat poorly to very poorly drained, which means ground that stays wet near the surface for significant periods. Where a seasonal water table is reported — 62% of acres — it averages 1.4 ft below grade, shallow enough to reach a typical crawl-space footing.
- 1Water table 1.4 ft
- 2Wet soils 50%
- 3Moisture score 43
- 4EPA radon zone 3
Reading the Kent County soil survey
The score of 43 combines four parts, each from the USDA survey: wet drainage classes contribute 54 points of 100 on their own scale, group D soils 34.7, a shallow water table 48.7, and flooding 9.5; the weights are on the methodology page. The dominant hydrologic group is C/D (28% 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 Kent County. Venting cannot fix that; it needs drainage — a perimeter drain to daylight or a sump — before any liner goes down.
Kent County against the rest of Delaware
Kent County ranks 1 of 3 Delaware counties, 2 points above the state median of 41. Only no other county in the state scores higher. Statewide, 40% of mapped soil is in the wet drainage classes; here it is 50%. After well drained, the next most common class is poorly drained at 26%.
Flooding. 2.2% of acres with a flooding class are rated frequent; 0.4% 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.
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 3. The zone is a county-level prediction; EPA says elevated levels occur in every zone and every home should be tested.
Near Kent County by score
Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area DE001; drainage covers 72% of 383,800 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.