Harlingen, Texas: what the ground under the city is like
Harlingen sits in Cameron County, on south texas plains. The soil mapped here is predominantly classified well drained — and that classification, not the rainfall total, is what decides how a slab foundation behaves.
Linear extensibility 8.8% — high.
31% of the mapped soil area around Harlingen is wet enough that the USDA describes it as needing artificial drainage.
Shallowest annual water table around 185 cm (6.1 ft).
Values are for Cameron County, which is what the soil survey resolves to. Full county report · soil map for a specific address.
The ground under Harlingen
South Texas Plains. Clayey and loamy sediments of the Rio Grande plain, semi-arid, caliche at depth
Expansive clay in a dry climate, which is the combination that produces the sharpest wet-dry cycle. Long droughts shrink the profile hard, then one wet season swells it back. Footings move seasonally and the movement is not uniform across a slab.
When it shows up here
| Slab moisture | 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 |
The mechanism here is the wet–dry cycle, and it peaks in the summer drought: clay shrinks hard from June to September, then the first heavy rain swells it back. Foundation cracks tend to appear at the ends of that swing, not during it.
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 Texas
| Reference job | Modelled range |
|---|---|
| Slab foundation lifted and stabilised on 12 piers | $16,900–$36,100 |
| Two slab cracks injected + regrading around the perimeter | $1,900–$6,300 |
| Engineer's report plus buried downspout discharge | $1,200–$4,150 |
Regional factor for TX: ×0.94. Full cost breakdown for Texas · run your own dimensions.
ZIP codes in Harlingen
78550, 78551, 78552, 78553
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.
Other places in Cameron County
Questions about Harlingen
Is the soil the same everywhere in Harlingen?
No. These values describe Cameron 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 Harlingen?
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 Harlingen
We pass what you enter to the contractor networks listed below. You choose whether to hire anyone.
Page data updated