Natchitoches, Louisiana: what the ground under the city is like
Natchitoches sits in Natchitoches Parish, on gulf coastal plain. 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 4.6% — moderate.
30% of the mapped soil area around Natchitoches is wet enough that the USDA describes it as needing artificial drainage.
Shallowest annual water table around 95 cm (3.1 ft).
Values are for Natchitoches Parish, which is what the soil survey resolves to. Full county report · soil map for a specific address.
The ground under Natchitoches
Gulf Coastal Plain. Unconsolidated sands and clays, pine uplands and broad flats
Extremely variable over short distances: deep sand on the ridges, saturated clay in the flats between them. High rainfall and a seasonally high water table make crawlspace and slab moisture the dominant complaint rather than structural movement.
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 |
Water peaks from August to October with the tropical season, when a single storm can deliver a season’s rain in two days. The spring dry spell is when clay movement shows up.
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 Louisiana
| Reference job | Modelled range |
|---|---|
| Slab foundation lifted and stabilised on 12 piers | $16,200–$34,550 |
| Two slab cracks injected + regrading around the perimeter | $1,800–$6,050 |
| Engineer's report plus buried downspout discharge | $1,150–$3,950 |
Regional factor for LA: ×0.90. Full cost breakdown for Louisiana · run your own dimensions.
ZIP codes in Natchitoches
71457, 71458, 71497
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 Natchitoches
Is the soil the same everywhere in Natchitoches?
No. These values describe Natchitoches Parish 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 Natchitoches?
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 Natchitoches
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Page data updated