GroundWise describes those conditions using two things: the USDA soil survey, which maps shrink-swell behaviour and restrictive-layer depth, and records of foundation repair work — third-party certified repair project records, and municipal building permits where a jurisdiction publishes them.
Everything here is area-level: the mapped soil unit and the census tract. Both are areas that routinely span many lots. Nothing on this site describes an individual property.
A county is far too coarse a unit to describe ground conditions. Every county below contains dozens of distinct soil-condition profiles, and within a single county the mapped shrink-swell runs from barely reactive to strongly expansive.
| County | USDA soil map units | Distinct soil-condition profiles | Range of mapped shrink-swell (LEP) |
|---|---|---|---|
| Williamson | 203 | 66 | 1.5–17.0% |
| Travis | 187 | 67 | 0.7–17.0% |
| Bexar | 157 | 58 | 0.7–17.0% |
| Atascosa | 153 | 45 | 1.5–17.0% |
| Bastrop | 150 | 32 | 1.5–17.0% |
| Wilson | 142 | 40 | 0.9–17.0% |
| Medina | 133 | 64 | 0.7–17.0% |
| Caldwell | 117 | 30 | 1.5–17.0% |
| Guadalupe | 107 | 37 | 0.7–17.0% |
| Hays | 91 | 48 | 0.7–17.0% |
| Comal | 89 | 46 | 0.7–17.0% |
| Bandera | 71 | 36 | 0.8–17.0% |
| Kendall | 71 | 44 | 0.7–17.0% |
A USDA soil map unit is a distinct mapped soil area identified by the soil survey — a mapped area typically larger than a single residential lot. A soil-condition profile is a distinct combination of the two mapped properties GroundWise reads: shrink-swell and depth to a restrictive layer. Shrink-swell is reported by the survey as linear extensibility percent (LEP), a measure of how much a soil expands and contracts with moisture. Source: USDA gSSURGO soil survey, counted within each county’s boundary (US Census TIGER 2023). Soil survey coverage of these counties is complete apart from open water — the largest gap is Canyon Lake in Comal County. These are survey-mapped values for mapped areas, not measurements taken at any particular parcel, and the exact location sampled within a map unit is not known.
Derived from the USDA soil survey for the soil map unit containing a location — principally shrink-swell (LEP) and the depth to a restrictive layer.
A soil map unit is a mapped area that routinely spans many lots. Two neighbouring homes in the same map unit get the same reading, because the underlying survey does not distinguish between them.
Reported for the census tract containing a location, relative to the metro median. The records behind it differ by foundation type:
A census tract contains thousands of homes. This is a measure of activity across an area — not a statement about any address in it, and not a record of whether any particular property has had work done.
Both signals are reported in parallel. Neither is blended into the other, and neither is a prediction. The reasoning, the data vintages, and a plain account of what the data does and does not support are on the methodology page.
When reports resume, a GroundWise report is a PDF describing conditions in the mapped areas that contain an address:
A report is a data report, not an inspection. It contains no observation of any structure, does not constitute professional engineering advice, and does not predict whether foundation movement will occur at a property or what any future work would involve. It should be treated as one input among several, never as the basis for a purchase, sale, lending, or insurance decision.
It is also expressly not a consumer report, and must not be used to decide anyone’s eligibility for credit, insurance, employment, housing, or tenancy.
Questions, or a request to delete information you gave us during the beta: support@groundwisedata.com. If you are writing about a specific report, please quote the report identifier printed on it.