“Excessively drained” soil: Water leaves this soil almost as fast as it arrives
Coarse sand and gravel, often glacial outwash or dune sand. Water moves through at rates measured in inches per hour.
What it means for a basement
A wet basement in excessively drained soil is usually not groundwater. Look at condensation, a plumbing leak, or a very local perched water table sitting on a buried clay or bedrock layer under the sand.
Where the USDA definition comes from
Drainage class is assigned per soil component in the national soil survey and describes frequency and duration of wet periods under conditions similar to those under which the soil formed. It is not a measurement taken at your house; it is a classification of a mapped soil body. That distinction is why we phrase every county page as a statement about soil, never as a statement about your basement.
USDA NRCS, National Soil Survey Handbook, part 618. Delivered per map unit in SSURGO.
Counties where “excessively drained” is the dominant class
0 counties in our coverage.
- No county in our coverage has this as its dominant class.
Page data updated