Maryland Soil Drainage Rankings
How well does the soil drain across Maryland? We ranked every USDA survey area by the percentage of land classified as "well drained." Areas at the top of the list have soils where water moves through at a healthy rate — favorable for building, septic, and gardening. Areas at the bottom have more waterlogged or slowly-draining soils that may require engineered solutions.
The best-drained survey area is Montgomery County, Maryland at 84% well-drained soils. The most drainage-challenged is Somerset County, Maryland at 7%. With 84% poorly-drained soils, properties in Somerset County, Maryland should budget for drainage engineering, alternative septic designs, or raised-bed gardening.
| # | Survey Area | Well Drained | Poorly Drained | Dominant Class |
|---|---|---|---|---|
| 1 | Montgomery County, Maryland | 84% | 9% | Well drained |
| 2 | Carroll County, Maryland | 81% | 9% | Well drained |
| 3 | Frederick County, Maryland | 81% | 6% | Well drained |
| 4 | Washington County, Maryland | 75% | 5% | Well drained |
| 5 | City of Baltimore, Maryland | 75% | 4% | Well drained |
| 6 | Garrett County, Maryland | 74% | 10% | Well drained |
| 7 | Howard County, Maryland | 73% | 8% | Well drained |
| 8 | Harford County Area, Maryland | 72% | 9% | Well drained |
| 9 | Baltimore County, Maryland | 71% | 10% | Well drained |
| 10 | Allegany County, Maryland | 66% | 1% | Well drained |
| 11 | Prince George's County, Maryland | 59% | 15% | Well drained |
| 12 | Cecil County, Maryland | 57% | 14% | Well drained |
| 13 | Anne Arundel County, Maryland | 53% | 15% | Well drained |
| 14 | Calvert County, Maryland | 50% | 11% | Well drained |
| 15 | Kent County, Maryland | 49% | 17% | Well drained |
| 16 | Caroline County, Maryland | 44% | 30% | Well drained |
| 17 | Queen Anne's County, Maryland | 44% | 36% | Well drained |
| 18 | St. Mary's County, Maryland | 42% | 21% | Well drained |
| 19 | Charles County, Maryland | 33% | 22% | Moderately well drained |
| 20 | Talbot County, Maryland | 30% | 47% | Well drained |
| 21 | Harford County, Aberdeen Proving Ground, Maryland | 15% | 46% | Moderately well drained |
| 22 | Dorchester County, Maryland | 15% | 71% | Poorly drained |
| 23 | Worcester County, Maryland | 12% | 55% | Poorly drained |
| 24 | Wicomico County, Maryland | 10% | 62% | Poorly drained |
| 25 | Somerset County, Maryland | 7% | 84% | Poorly drained |