Texas / Val Verde County

Score 23 · moderate · #63 of 209 in TX

Crawl space moisture in Val Verde County, TX

88% of Val Verde 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 — 0% of acres — it averages 4.6 ft below grade.

Size venting or encapsulation

1234
  1. 1Water table 4.6 ft
  2. 2Wet soils 0%
  3. 3Moisture score 23
  4. 4EPA radon zone 3
Excessively1%Well99%Moderately well0%
Share of mapped soil acres in Val Verde County, TX by NRCS drainage class (dominant condition), bars to scale; wetter classes highlighted. Covers 93% of mapped acres.
Dominant drainage
Well drained
99% of acres
Group D soils
88%
slow infiltration
Flood-prone acres
6%
any flooding frequency
Ponding
4.4%
acres where water ponds

Reading the Val Verde County soil survey

The score of 23 combines four parts, each from the USDA survey: wet drainage classes contribute 0 points of 100 on their own scale, group D soils 88.6, a shallow water table 0, and flooding 5; the weights are on the methodology page. The dominant hydrologic group is D (88% of acres): very slow infiltration, high runoff (clays, high water table).

5%A6%B1%C88%D
Hydrologic soil groups in Val Verde 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 4.6 ft the seasonal water table is usually below a crawl-space floor, but the 0% 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.

Val Verde County against the rest of Texas

Val Verde County ranks 63 of 209 Texas counties, 5 points above the state median of 18. 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 0%, 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 excessively drained at 1%.

Flooding. 4.7% of acres with a flooding class are rated frequent; 0% of acres with a flooding class are rated occasional; 1.3% 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 4.4% of acres.

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 3. The zone is a county-level prediction; EPA says elevated levels occur in every zone and every home should be tested.

Near Val Verde County by score

All 209 Texas counties

Sources: USDA NRCS SSURGO via Soil Data Access (muaggatt: drclassdcd, hydgrpdcd, flodfreqdcd, pondfreqprs, wtdepannmin), acreage-weighted (survey area TX465; drainage covers 93% of 2,069,031 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.