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Mannings N: table 2
8. on irregular excavated rock to g. sluggish reaches, weedy, deep pools
Manning's n roughness coefficients for open channels and closed conduits — used in hydraulic flow calculations
| section | description | n max (dimensionless) | n min (dimensionless) | n normal (dimensionless) | subcategory |
|---|---|---|---|---|---|
| table 2 | a. bottom: gravels, cobbles, and few boulders | 0.05 | 0.03 | 0.04 | 2. Mountain streams, no vegetation in channel, banks usually steep, trees and brush along banks submerged at high stages |
| table 2 | a. clean, straight, full stage, no rifts or deep pools | 0.033 | 0.025 | 0.03 | 1. Main Channels |
| table 2 | b. bottom: cobbles with large boulders | 0.07 | 0.04 | 0.05 | 2. Mountain streams, no vegetation in channel, banks usually steep, trees and brush along banks submerged at high stages |
| table 2 | b. same as above, but more stones and weeds | 0.04 | 0.03 | 0.035 | 1. Main Channels |
| table 2 | c. clean, winding, some pools and shoals | 0.045 | 0.033 | 0.04 | 1. Main Channels |
| table 2 | d. same as above, but some weeds and stones | 0.05 | 0.035 | 0.045 | 1. Main Channels |
| table 2 | e. same as above, lower stages, more ineffective slopes and sections | 0.055 | 0.04 | 0.048 | 1. Main Channels |
| table 2 | f. same as "d" with more stones | 0.06 | 0.045 | 0.05 | 1. Main Channels |
| table 2 | g. sluggish reaches, weedy, deep pools | 0.08 | 0.05 | 0.07 | 1. Main Channels |
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