Value of ‘n’ for different types of the channel

 

Types of channel

‘n’

A.   Earth Channel

 

       I.            Straight or uniform

0.023

    II.            Small drainage ditches

0.04

 

 

B.   Lined channels

 

I. Concrete

0.015

II. Masonary rubble

0.017 to 0.030

 

 

C.   Pipe (cast iron)

0.012 to 0.013