North Dakota / LaMoure County

Score 24 · moderate · #26 of 53 in ND

Crawl space moisture in LaMoure County, ND

LaMoure County scores moderate: no single wet-soil signal dominates its mapped acres. Where a seasonal water table is reported — 88% of acres — it averages 3.3 ft below grade.

Size venting or encapsulation

1234
  1. 1Water table 3.3 ft
  2. 2Wet soils 16%
  3. 3Moisture score 24
  4. 4EPA radon zone 1
Excessively1%Somewhat excessively2%Well44%Moderately well37%Somewhat poorly5%Poorly5%Very poorly7%
Share of mapped soil acres in LaMoure County, ND by NRCS drainage class (dominant condition), bars to scale; wetter classes highlighted. Covers 99% of mapped acres.
Dominant drainage
Well drained
44% of acres
Group D soils
12%
slow infiltration
Flood-prone acres
5%
any flooding frequency
Ponding
0.3%
acres where water ponds

Reading the LaMoure County soil survey

The score of 24 combines four parts, each from the USDA survey: wet drainage classes contribute 27 points of 100 on their own scale, group D soils 9.3, a shallow water table 43.5, and flooding 4; the weights are on the methodology page. The dominant hydrologic group is B (80% of acres): moderate infiltration.

2%A80%B7%C0%D0%A/D2%B/D9%C/D
Hydrologic soil groups in LaMoure 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 3.3 ft the seasonal water table is usually below a crawl-space floor, but the 88% 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.

LaMoure County against the rest of North Dakota

LaMoure County ranks 26 of 53 North Dakota counties, level with the state median of 24. That places it in the middle range, nationally and for the state. Statewide, 23% of mapped soil is in the wet drainage classes; here it is 16%, below the state figure — the score here comes from a shallow water table rather than drainage class alone. After well drained, the next most common class is moderately well drained at 37%.

Flooding. 2.8% of acres with a flooding class are rated frequent; 1.9% of acres with a flooding class are rated occasional; 0.1% of acres with a flooding class are rated rare; 0.5% of acres with a flooding class are rated very rare. 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 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. LaMoure County is in EPA radon zone 1, the highest predicted potential. A sealed crawl space and a radon system share most of their parts — the liner, the sealed seams, a fan — so if you are encapsulating, test for radon first and design both together. EPA itself says the zone map is not a reason to skip testing in zones 2 and 3.

Near LaMoure County by score

All 53 North Dakota counties

Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area ND045; drainage covers 99% of 738,000 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.