Saint George, Utah: what the ground under the city is like
Saint George sits in Washington County, on basin and range. The soil mapped here is predominantly classified well drained — and that classification, not the rainfall total, is what decides how a basement behaves.
21% of the mapped soil area around Saint George is wet enough that the USDA describes it as needing artificial drainage.
Linear extensibility 8.6% — high.
Shallowest annual water table around 185 cm (6.1 ft).
Values are for Washington County, which is what the soil survey resolves to. Full county report · soil map for a specific address.
The ground under Saint George
Basin and Range. Alluvial fans and lacustrine sediments of former Lake Bonneville
Semi-arid, but the lacustrine clays on the basin floors are expansive while parts of the fans are collapsible — they settle when wetted. Two opposite failure modes in one metropolitan area.
When it shows up here
| Water | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ground movement | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Rainfall is low all year, so the water line stays flat. What moves is the ground: the late spring and early summer dry-down is the sharpest part of the cycle, and summer monsoon storms end it abruptly.
Climate pattern for this physiographic region, not a forecast for your house and not from the soil survey. It answers a question homeowners actually ask: when does this show up.
What repairs cost in Utah
| Reference job | Modelled range |
|---|---|
| Interior drain along two walls + sump pump | $5,200–$11,200 |
| Exterior excavation of one 40 ft wall | $3,900–$11,100 |
| Underpinning on 10 piers | $15,450–$32,950 |
Regional factor for UT: ×1.03. Full cost breakdown for Utah · run your own dimensions.
ZIP codes in Saint George
84770, 84771, 84790, 84791
Soil does not stop at a city boundary, and neither does this data — every ZIP code above resolves to the same county soil survey. For the individual survey polygons around one address, use the soil map.
Questions about Saint George
Is the soil the same everywhere in Saint George?
No. These values describe Washington County as a whole, which is the unit the soil survey publishes. Within a city, map units change over a few hundred metres — the soil map draws the actual polygons around a point and is the honest answer for one address.
Which contractor should I call in Saint George?
We do not rank or recommend individual firms and we are not one. What this page is for is knowing which kind of work the ground here points to before anyone quotes you, and which claim to check. If you want quotes, the form below passes your request to the named networks.
Does this replace an inspection?
No. It tells you what the ground is; an inspection tells you what your building is doing on it. The useful order is: read this, print the brief for your county, then have someone look.
Get quotes in Saint George
We pass what you enter to the contractor networks listed below. You choose whether to hire anyone.
Page data updated