Soils in St. Mary's County, Maryland
St. Mary's County, Maryland has 100,902 acres of well-drained soil across 88 distinct soil map units. The map below shows every NRCS soil map unit inside the county boundary.
St. Mary's County, Maryland at a glance
| Well-drained land | 100,902 acres |
|---|---|
| Share of mapped soil that is well drained | 39.3% |
| Poorly drained land | 51,950 acres |
| Most common drainage class | Well drained — 96,147 acres |
| Distinct soil map units | 88 |
| Largest soil map unit | Beltsville silt loam, 2 to 5 percent slopes, moderately eroded — 32,855 acres |
| Share with hydrologic soil group A or B (high infiltration) | 25.7% |
| Typical shallowest annual water table | 24 in below the surface |
St. Mary's County, Maryland is home to 116,692 residents. Land Owl's soils layer records the following within the county boundary — Well-drained land: 100,902 acres. Share of mapped soil that is well drained: 39.3%. Poorly drained land: 51,950 acres. Most common drainage class: Well drained — 96,147 acres. Distinct soil map units: 88. Largest soil map unit: Beltsville silt loam, 2 to 5 percent slopes, moderately eroded — 32,855 acres. Share with hydrologic soil group A or B (high infiltration): 25.7%. Typical shallowest annual water table: 24 in below the surface. Every feature shown on the map above is clickable, and the figures on this page are derived from the same data the map renders, so they always agree. A free Land Owl account adds parcel boundaries, ownership records, flood zones, wetlands and topography over the same view.
Frequently asked questions
- What are the soils like in St. Mary's County, Maryland?
- The USDA soil survey maps 100,902 acres of St. Mary's County, Maryland as well drained and 51,950 acres as poorly drained. Drainage class and hydrologic soil group are the two properties that most often decide whether a rural lot can take a septic system and a driveway.
- Is this soil map free to use?
- Yes. This map is free to view. A free Land Owl account unlocks the other data layers, parcel boundaries and ownership records.
- Where does this data come from?
- Land Owl maps soils from the USDA Natural Resources Conservation Service SSURGO soil survey. SSURGO describes soil MAP UNITS at survey scale — it is a screening tool for shortlisting land, not a substitute for a site-specific soil evaluation or a septic percolation test, both of which your health department will want before it permits a system.
- Can I use this soil map to tell whether land will perc?
- It is the right place to start and the wrong place to finish. Drainage class and hydrologic soil group tell you which parcels are worth a site visit, but a health department permits a septic system on a percolation test dug on the actual lot, not on the survey.
See every layer over St. Mary's County
Parcel boundaries, ownership, flood zones, soils, wetlands and topography on one map.
Sign up free