| maximum |
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|
normal |
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|
minimum |
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|
type of channel and discription |
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| D. Natural Streams |
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| (D-1. Minor streams (top width at flood stage<100 ft |
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| a. Streams on plain |
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| ۰/۰۳۳ |
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۰/۰۳۰ |
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۰/۰۲۵ |
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|
1. Clean, straight, full stage, no rifts or deep pools |
|
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| ۰/۰۴۰ |
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۰/۰۳۵ |
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۰/۰۳۰ |
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2. Same as above, but more stones and weeds |
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| ۰/۰۴۵ |
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۰/۰۴۰ |
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۰/۰۳۳ |
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3. Clean, winding, some pools and shoals |
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| ۰/۰۵۰ |
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۰/۰۴۵ |
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۰/۰۳۵ |
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|
4. Same as above ,but some weeds and stones |
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| ۰/۰۵۵ |
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۰/۰۴۸ |
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|
۰/۰۴۰ |
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|
5. Same as above, lower stages, more ineffective slopes and sections |
|
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| ۰/۰۶۰ |
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۰/۰۵۰ |
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|
۰/۰۴۵ |
|
|
6. Same as 4, but more stones |
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|
|
| ۰/۰۸۰ |
|
|
۰/۰۷۰ |
|
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۰/۰۵۰ |
|
|
7. Sluggish reaches, weedy, deep pools |
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| ۰/۱۵۰ |
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|
۰/۱۰۰ |
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۰/۰۷۵ |
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|
8. Very weedy reaches, deep pools, or floodways with heavy stand of timber and underbrush |
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b. Mountain stureams, no vegetation in channel, banks usually steep, trees and brush along banks submerged at high stages |
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|
| ۰/۰۵۰ |
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|
۰/۰۴۰ |
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|
۰/۰۳۰ |
|
|
1. Bottom^ cobbles with large boulders |
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| ۰/۰۷۰ |
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|
۰/۰۵۰ |
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|
۰/۰۴۰ |
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2. Bottom: cobbles with large boulders |
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| D-2 Flood plains |
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| a. pasture, no bush |
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| ۰/۰۳۵ |
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|
۰/۰۳۰ |
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|
۰/۰۲۵ |
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|
1. Short grass |
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| ۰/۰۵۰ |
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|
۰/۰۳۵ |
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|
۰/۰۳۰ |
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|
2. high grass |
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| b. cultivated areas |
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| ۰/۰۴۰ |
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|
۰/۰۳۰ |
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|
۰/۰۲۰ |
|
|
1. No crop |
|
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| ۰/۰۴۵ |
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|
۰/۰۳۵ |
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|
۰/۰۲۵ |
|
|
2. Mature field crops |
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| ۰/۰۵۰ |
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|
۰/۰۴۰ |
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|
۰/۰۳۰ |
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3. Mature field crops |
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| c. Brush |
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| ۰/۰۷۰ |
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|
۰/۰۵۰ |
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|
۰/۰۳۵ |
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|
1. Scattered brush, heavy weeds |
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| ۰/۰۶۰ |
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|
۰/۰۵۰ |
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|
۰/۰۳۵ |
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|
2. Light brush and trees, in winter |
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| ۰/۰۸۰ |
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|
۰/۰۶۰ |
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|
۰/۰۴۰ |
|
|
3. Light brush and trees , in summer |
|
|
|
| ۰/۱۱۰ |
|
|
۰/۱۰۰ |
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|
۰/۰۷۵ |
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|
5. medium to dense brush, in summer |
|
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|
| d. Trees |
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|
| ۰/۲۰۰ |
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|
۰/۱۵۰ |
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|
۰/۱۱۰ |
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|
1. Dense willows, summer, straight |
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| ۰/۰۵۰ |
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|
۰/۰۴۰ |
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|
۰/۰۳۰ |
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2. Cleared land with tree stumps, no sprouts |
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| ۰/۰۸۰ |
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|
۰/۰۶۰ |
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|
۰/۰۵۰ |
|
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3. Same as above, but with heavy growth of sprouts |
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| ۰/۱۲۰ |
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۰/۱۰۰ |
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۰/۰۸۰ |
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4. Heavy stand of timber, a few down trees, little undergrowth, flood stage below branches |
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| ۰/۱۶۰ |
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۰/۱۲۰ |
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۰/۱۰۰ |
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5. Same as above, but with flood stage reaching branches |
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(D-3. Major streams (top width at flood,stage>100ft
. The n value is less than that for minor streams of similar description, because banks offer less effective resistance |
|
|
|
| ۰/۰۶۰ |
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|
- |
|
|
۰/۰۲۵ |
|
|
a. Regular section with no boulders or brush |
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|
|
| ۰/۱۰۰ |
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|
- |
|
|
۰/۰۳۵ |
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|
b. Irregular and rough section |
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|
