The efficient application and distribution of
water by irrigation furrows or borders is highly
dependent on the rate of advance of water in these
channels. The rate of advance is governed by the
intake rate of the soil, the resistance offered by
the channels to the flow of water, and the discharge
rate into the channels. A knowledge of these
factors is essential for the design of efficient irrigation
systems. Intake rate has been the object
of much study and methods are available for its
measurement before the construction of irrigation
systems. Previous flow resistance studies have
dealt with either artificially roughened boundaries,
conduits intended for uses other than irrigation,
or discharges much greater than are likely to
occur in small irrigation channels. Results of
studies of flow resistance are not available for the
types of roughness, sizes of channels, and discharges
that are likely to be encountered in surface
irrigation systems. Discharge can be regulated
to correspond to other design conditions
