m |
m |
||
Line 11: | Line 11: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
− | <td>Open space (<50% cover)</td> | + | <td>Open space poor condition (<50% cover)</td> |
<td>68</td> | <td>68</td> | ||
<td>79</td> | <td>79</td> | ||
Line 18: | Line 18: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
− | <td>Open space (50-75% cover)</td> | + | <td>Open space average condition (50-75% cover)</td> |
<td>49</td> | <td>49</td> | ||
<td>69</td> | <td>69</td> | ||
Line 25: | Line 25: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
− | <td>Open space (<75% cover)</td> | + | <td>Open space good condition (<75% cover)</td> |
<td>39</td> | <td>39</td> | ||
<td>61</td> | <td>61</td> |
Curve numbers for urban and agricultural areas. Source: 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 poor condition (<50% cover) | 68 | 79 | 86 | 89 |
Open space average condition (50-75% cover) | 49 | 69 | 79 | 84 |
Open space good condition (<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 |