Curve numbers for urban and agricultural areas
Curve numbers for urban and agricultural areas. Source: [https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044171.pdf USDA Urban Hydrology for Small Watersheds - TR-55 .
Link to this Curve numbers for urban and agricultural areas
| Cover type and hydrologic condition | Soil Group A | Soil Group B | Soil Group C | Soil Group D |
|---|---|---|---|---|
| Open space (<50% cover) | 68 | 79 | 86 | 89 |
| Open space (50-75% cover) | 49 | 69 | 79 | 84 |
| Open space (<75% cover) | 39 | 61 | 74 | 80 |
| Impervious surfaces | 98 | 98 | 98 | 98 |
| Commercial (85% impervious) | 89 | 92 | 94 | 95 |
| Industrial (72% impervious) | 81 | 88 | 91 | 93 |
| Residential (65% impervious) | 77 | 85 | 90 | 92 |
| Residential (30% impervious) | 57 | 72 | 81 | 86 |
| Residential (12% impervious) | 46 | 65 | 77 | 82 |
| Pervious, no vegetation (newly graded) | 77 | 86 | 91 | 94 |
| Fallow with residue cover | 74-76 | 83-85 | 88-90 | 90-93 |
| Row crop, no residue | 67-72 | 78-81 | 85-88 | 89-91 |
| Row crop with residue | 64-71 | 75-80 | 82-87 | 85-90 |
| Pasture, good condition | 39 | 61 | 74 | 80 |
| Pasture, poor condition | 68 | 79 | 86 | 89 |
| Meadow | 30 | 58 | 71 | 78 |
| Woods, good condition | 32 | 58 | 72 | 79 |
| Woods, poor condition | 57 | 73 | 82 | 86 |