Crawl Space Map

North Carolina / Northampton County

Score 44 · elevated · #29 of 100 in NC

Crawl space moisture in Northampton County, NC

53% of Northampton 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 — 86% of acres — it averages 2 ft below grade.

Size venting or encapsulation

1234
  1. 1Water table 2 ft
  2. 2Wet soils 34%
  3. 3Moisture score 44
  4. 4EPA radon zone 3
Somewhat excessively1%Well34%Moderately well31%Somewhat poorly8%Poorly26%
Share of mapped soil acres in Northampton County, NC by NRCS drainage class (dominant condition), bars to scale; wetter classes highlighted. Covers 97% of mapped acres.
Dominant drainage
Well drained
34% of acres
Group D soils
53%
slow infiltration
Flood-prone acres
21%
any flooding frequency
Ponding
0%
acres where water ponds

Reading the Northampton County soil survey

The score of 44 combines four parts, each from the USDA survey: wet drainage classes contribute 41.9 points of 100 on their own scale, group D soils 42.7, a shallow water table 59.8, and flooding 14.2; the weights are on the methodology page. The dominant hydrologic group is B (34% of acres): moderate infiltration.

2%A34%B11%C19%D2%A/D14%B/D19%C/D
Hydrologic soil groups in Northampton 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 86% 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.

Northampton County against the rest of North Carolina

Northampton County ranks 29 of 100 North Carolina counties, 27 points above the state median of 17. Wetter counties exist in North Carolina, but the soil here still sits well above the national middle. Statewide, 30% of mapped soil is in the wet drainage classes; here it is 34%. After well drained, the next most common class is moderately well drained at 31%.

Flooding. 11% of acres with a flooding class are rated frequent; 2.9% of acres with a flooding class are rated occasional; 7.3% 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 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 Northampton County by score

Duplin County 44Wilson County 44Lenoir County 45Edgecombe County 42

All 100 North Carolina counties

Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area NC131; drainage covers 97% of 351,757 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.