St. Johns County, Florida
The most common soil here is Riviera, on about 10% of the land: a sand, loose sand that holds almost no water. Myakka and Pomona come next.
About 3% of the land drains well, and 85% stays wet for long stretches; groundwater comes within two feet of the surface under 78% of it.
USDA rates 91% of the land very limited for a standard septic drain field, and 83% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 22% of the land floods occasionally or more.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in St. Johns County, Florida, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Poorly drained and the dominant hydrologic group is A/D (varies with drainage). The most common soil order is Entisols — young soils with little profile development, often on floodplains or steep slopes. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in St. Johns County, Florida. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Myakka-Myakka, wet, fine sands, 0 to 2 percent slopes | 40K | Poorly drained | A/D | Very limited | Very limited |
| Water | 34K | Not rated | Not rated | ||
| Pomona fine sand | 32K | Poorly drained | B/D | Very limited | Very limited |
| Riviera fine sand, frequently flooded | 27K | Poorly drained | C/D | Very limited | Very limited |
| Tocoi fine sand | 21K | Poorly drained | A/D | Very limited | Very limited |
| Immokalee fine sand | 20K | Poorly drained | A/D | Very limited | Very limited |
| Pellicer silty clay loam, frequently flooded | 17K | Very poorly drained | D | Very limited | Very limited |
| Holopaw fine sand | 17K | Poorly drained | A/D | Very limited | Very limited |
| Riviera fine sand | 16K | Poorly drained | C/D | Very limited | Very limited |
| Smyrna-Smyrna, wet, fine sand, 0 to 2 percent slopes | 11K | Poorly drained | A/D | Very limited | Very limited |
| Terra Ceia muck, 0 to 1 percent slopes, frequently flooded | 10K | Very poorly drained | A/D | Very limited | Very limited |
| St. Johns fine sand | 10K | Poorly drained | B/D | Very limited | Very limited |
| Holopaw fine sand, frequently flooded | 10K | Very poorly drained | A/D | Very limited | Very limited |
| Floridana fine sand, 0 to 2 percent slopes | 9K | Very poorly drained | C/D | Very limited | Very limited |
| Placid fine sand | 9K | Very poorly drained | A/D | Very limited | Very limited |
| Tavares fine sand, 0 to 5 percent slopes | 8K | Moderately well drained | A | Very limited | Very limited |
| Zolfo fine sand | 7K | Somewhat poorly drained | A | Somewhat limited | Very limited |
| Ellzey fine sand | 6K | Poorly drained | B/D | Very limited | Very limited |
| EauGallie fine sand | 6K | Poorly drained | A/D | Very limited | Very limited |
| St. Johns fine sand, depressional | 6K | Very poorly drained | B/D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 83% of soils are rated "very limited" for dwellings with basements. Specific challenges include poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 91% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.