Hydrologic soil group |
Infiltration rate (inches/hour) |
Soil textures |
Corresponding Unified Soil Classification |
A |
1.6a |
- gravel
- sandy gravel
- silty gravels
|
- GW - well-graded gravels, sandy gravels
- GP - gap-graded or uniform gravels, sandy gravels
- GM - silty gravels, silty sandy gravels
- SW - well-graded gravelly sands
|
0.8 |
- sand
- loamy sand
- sandy loam
|
SP - gap-graded or uniform sands, gravelly sands
|
B |
0.6 |
silt loam |
SM - silty sands, silty gravelly sands |
0.3 |
loam |
MH - micaceous silts, diatomaceous silts, volcanic ash |
C |
0.2 |
Sandy clay loam |
ML - silts, very fine sands, silty or clayey fine sands |
D |
<0.2 |
- clay loam
- silty clay loam
- sandy clay
- silty clay
- clay
|
- GC - clayey gravels, clayey sandy gravels
- SC - clayey sands, clayey gravelly sands
- CL - low plasticity clays, sandy or silty clays
- OL - organic silts and clays of low plasticity
- CH - highly plastic clays and sandy clays
- OH - organic silts and clays of high plasticity
|