Nevada / Northwest Elko County
Score 21 · moderate · #8 of 18 in NV
Crawl space moisture in Northwest Elko County, NV
62% of Northwest Elko 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 — 4% of acres — it averages 1 ft below grade, shallow enough to reach a typical crawl-space footing.
- 1Water table 1 ft
- 2Wet soils 3%
- 3Moisture score 21
- 4EPA radon zone n/a
Reading the Northwest Elko County soil survey
The score of 21 combines four parts, each from the USDA survey: wet drainage classes contribute 2.7 points of 100 on their own scale, group D soils 72.1, a shallow water table 3.1, and flooding 11.5; the weights are on the methodology page. The dominant hydrologic group is D (61% of acres): very slow infiltration, high runoff (clays, high water table).
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 on the soils that report a water table — about 4% of Northwest Elko County's acres. Venting cannot fix that; it needs drainage — a perimeter drain to daylight or a sump — before any liner goes down.
Northwest Elko County against the rest of Nevada
Northwest Elko County ranks 8 of 18 Nevada counties, level with the state median of 21. That places it in the middle range, nationally and for the state. Statewide, 6% of mapped soil is in the wet drainage classes; here it is 3%, below the state figure — the score here comes from heavy group D soils rather than drainage class alone. After well drained, the next most common class is poorly drained at 2%.
Flooding. 7.8% of acres with a flooding class are rated frequent; 4% of acres with a flooding class are rated occasional; 6.5% 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.
Near Northwest Elko County by score
Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area NV763; drainage covers 100% of 1,892,316 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.