Virginia / Chesapeake City
Score 73 · high · #1 of 95 in VA
Crawl space moisture in Chesapeake City, VA
92% of Chesapeake City'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 — 92% of acres — it averages 0.5 ft below grade, shallow enough to reach a typical crawl-space footing.
- 1Water table 0.5 ft
- 2Wet soils 92%
- 3Moisture score 73
- 4EPA radon zone n/a
Reading the Chesapeake City soil survey
The score of 73 combines four parts, each from the USDA survey: wet drainage classes contribute 92 points of 100 on their own scale, group D soils 58, a shallow water table 85.1, and flooding 9; the weights are on the methodology page. The dominant hydrologic group is B/D (70% of acres): D when undrained, B 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 Chesapeake City. Venting cannot fix that; it needs drainage — a perimeter drain to daylight or a sump — before any liner goes down.
Chesapeake City against the rest of Virginia
Chesapeake City ranks 1 of 95 Virginia counties, 61 points above the state median of 12. Only no other county in the state scores higher. Statewide, 11% of mapped soil is in the wet drainage classes; here it is 92%, half again the state figure or more. After poorly drained, the next most common class is very poorly drained at 40%.
Flooding. 8.1% of acres with a flooding class are rated frequent. 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 2.3% of acres.
What it means for a crawl space here
In a high county, the model-code default of a vented crawl space over bare earth works against the soil: outside air brings humidity in all summer, and the ground underneath keeps supplying moisture from below. The R408 alternative — an unvented crawl space with a sealed vapor retarder lapped 6 inches and turned 6 inches up the stem wall, plus conditioned or exhaust air at 1 cfm per 50 sq ft or a dehumidifier — is built for exactly this. If the water table is shallow, drainage comes first.
Near Chesapeake City by score
Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area VA550; drainage covers 92% of 230,600 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.