Score 43 · elevated · #15 of 46 in SC

Crawl space moisture in Bamberg County, SC

Bamberg County scores elevated because several moderate signals stack up rather than one dominant one. Where a seasonal water table is reported — 91% of acres — it averages 2 ft below grade.

Size venting or encapsulation

1Water table 2 ft
2Wet soils 43%
3Moisture score 43
4EPA radon zone 3

Share of mapped soil acres in Bamberg County, SC by NRCS drainage class (dominant condition), bars to scale; wetter classes highlighted. Covers 99% of mapped acres.

Dominant drainage

Poorly drained

31% of acres

Group D soils

43%

slow infiltration

Flood-prone acres

14%

any flooding frequency

Ponding

10.6%

acres where water ponds

Reading the Bamberg County soil survey

The score of 43 combines four parts, each from the USDA survey: wet drainage classes contribute 44.6 points of 100 on their own scale, group D soils 31.3, a shallow water table 62.7, and flooding 12.7; the weights are on the methodology page. The dominant hydrologic group is B (30% of acres): moderate infiltration.

Hydrologic soil groups in Bamberg 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 2 ft the seasonal water table is usually below a crawl-space floor, but the 91% 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.

Bamberg County against the rest of South Carolina

Bamberg County ranks 15 of 46 South Carolina counties, 18 points above the state median of 25. Wetter counties exist in South Carolina, but the soil here still sits well above the national middle. Statewide, 34% of mapped soil is in the wet drainage classes; here it is 43%. After poorly drained, the next most common class is well drained at 31%.

Flooding. 12.4% of acres with a flooding class are rated frequent; 1.4% 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. Ponding — water standing at the surface with nowhere to go — affects 10.6% 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 3. The zone is a county-level prediction; EPA says elevated levels occur in every zone and every home should be tested.

Near Bamberg County by score

Sumter County 42 Marlboro County 41 Orangeburg County 41 Clarendon County 46

All 46 South Carolina counties

Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area SC009; drainage covers 99% of 253,000 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.