GLG410 manning coefficients for english units

This table comes from Ritter, et al., Process Geomorphology, 3rd ed., Wm. C. Brown Publishers, 1995.

Manning roughness coefficients (n) for different boundary types

Boundary Manning n (ft1/6)
Very smooth surfaces such as glass, plastic, or brass 0.010
Very smooth concrete and planed timber 0.011
Smooth concrete 0.012
Ordinary concrete lining 0.013
Good wood 0.014
Vitrified clay 0.015
Shot concrete, untroweled, and earth channels in best condition 0.017
Straight unlined earth canals in good condition 0.020
Rivers and earth canals in fair condition; some growth 0.025
Winding natural streams and canals in poor condition; considerable moss growth 0.035
Mountain streams with rocky beds and rivers with variable sections and some vegetation along banks 0.041-0.050

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Prof. Ramón Arrowsmith

Last modified November 28, 1999