Hach AS950 - Page 34

Table 13 Lined or built-up channels (continued)
Concrete Trowel finish 0.011 0.013 0.015
Float finish 0.013 0.015 0.016
Finished, with gravel
on bottom
0.015 0.017 0.020
Unfinished 0.014 0.017 0.020
Wood Planed, untreated 0.010 0.012 0.014
Planed, creosoted 0.011 0.012 0.015
Unplaned 0.011 0.013 0.015
Plank with battens 0.012 0.015 0.018
Brick Glazed 0.011 0.013 0.015
In cement mortar 0.012 0.015 0.018
Masonry Cemented rubble 0.017 0.025 0.030
Dry rubble 0.023 0.032 0.035
Asphalt Smooth 0.013 0.013 —
Rough 0.016 0.016 —
Vegetal lining — 0.030 — 0.500
Excavated or dredged
Earth, straight and uniform 0.016 0.022 0.035
Earth, winding and sluggish 0.023 0.030 0.040
Rock cuts 0.030 0.040 0.050
Not maintained channels 0.040 0.070 0.140
Natural channels (minor streams, top width at flood 30.5 m (100 ft.))
Fairly regular section 0.030 0.050 0.070
Irregular section with pools 0.040 0.070 0.100
32 English