Alabama / Bullock County

Score 36 · moderate · #7 of 67 in AL

Crawl space moisture in Bullock County, AL

57% of Bullock 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 — 42% of acres — it averages 2 ft below grade.

Size venting or encapsulation

1234
  1. 1Water table 2 ft
  2. 2Wet soils 23%
  3. 3Moisture score 36
  4. 4EPA radon zone 2
Somewhat excessively0%Well30%Moderately well46%Somewhat poorly23%Poorly0%
Share of mapped soil acres in Bullock County, AL by NRCS drainage class (dominant condition), bars to scale; wetter classes highlighted. Covers 100% of mapped acres.
Dominant drainage
Moderately well drained
46% of acres
Group D soils
57%
slow infiltration
Flood-prone acres
22%
any flooding frequency
Ponding
0%
acres where water ponds

Reading the Bullock County soil survey

The score of 36 combines four parts, each from the USDA survey: wet drainage classes contribute 31 points of 100 on their own scale, group D soils 58.9, a shallow water table 29.2, and flooding 19.2; the weights are on the methodology page. The dominant hydrologic group is D (40% of acres): very slow infiltration, high runoff (clays, high water table).

12%A2%B30%C40%D5%B/D12%C/D
Hydrologic soil groups in Bullock 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 42% 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.

Bullock County against the rest of Alabama

Bullock County ranks 7 of 67 Alabama counties, 14 points above the state median of 22. That puts it in the wettest quarter of the state. Statewide, 16% of mapped soil is in the wet drainage classes; here it is 23%. After moderately well drained, the next most common class is well drained at 30%.

Flooding. 18.3% of acres with a flooding class are rated frequent; 0.3% of acres with a flooding class are rated occasional; 3.7% of acres with a flooding class are rated rare. That is a large flood-prone share; a crawl space in the floodplain needs flood vents under most local floodplain ordinances, which is a separate rule from R408 and can rule out a fully sealed design.

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. 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 Bullock County by score

All 67 Alabama counties

Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area AL011; drainage covers 100% of 401,060 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.